{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://overlord.local/schemas/wire-contract.schema.json",
  "title": "Overlord wire contract",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "schemaVersion",
    "protocolVersion",
    "encoding",
    "compatibility",
    "commandVersioning",
    "serverToAgentMessageTypes",
    "agentToServerMessageTypes",
    "commands"
  ],
  "properties": {
    "$schema": { "type": "string" },
    "schemaVersion": { "type": "integer", "minimum": 1 },
    "protocolVersion": { "type": "integer", "minimum": 1 },
    "encoding": { "const": "messagepack" },
    "compatibility": { "enum": ["additive"] },
    "commandVersioning": {
      "type": "object",
      "additionalProperties": false,
      "required": ["defaultVersion", "overrides"],
      "properties": {
        "defaultVersion": { "const": 1 },
        "overrides": {
          "type": "object",
          "propertyNames": { "$ref": "#/$defs/wireName" },
          "additionalProperties": {
            "type": "object",
            "additionalProperties": false,
            "required": ["latestVersion", "changes"],
            "properties": {
              "latestVersion": { "type": "integer", "minimum": 2 },
              "minVersion": { "type": "integer", "minimum": 1 },
              "changes": {
                "type": "object",
                "patternProperties": {
                  "^[2-9][0-9]*$": {
                    "type": "object",
                    "additionalProperties": false,
                    "required": ["breaking", "summary", "migration"],
                    "properties": {
                      "breaking": { "const": true },
                      "summary": { "type": "string", "minLength": 1 },
                      "migration": { "type": "string", "minLength": 1 }
                    }
                  }
                },
                "additionalProperties": false
              }
            }
          }
        }
      }
    },
    "serverToAgentMessageTypes": {
      "type": "array",
      "uniqueItems": true,
      "items": { "$ref": "#/$defs/wireName" }
    },
    "agentToServerMessageTypes": {
      "type": "array",
      "uniqueItems": true,
      "items": { "$ref": "#/$defs/wireName" }
    },
    "commands": {
      "type": "array",
      "uniqueItems": true,
      "items": { "$ref": "#/$defs/wireName" }
    }
  },
  "$defs": {
    "wireName": {
      "type": "string",
      "pattern": "^[a-z][a-z0-9]*(?:_[a-z0-9]+)*$"
    }
  }
}