{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://git.eeqj.de/sneak/chat/schema/message.json",
  "title": "IRC Message Envelope",
  "description": "Base envelope for all messages. Mirrors IRC wire format (RFC 1459/2812) encoded as JSON over HTTP. The 'command' field carries either an IRC command name (PRIVMSG, JOIN, etc.) or a three-digit numeric reply code (001, 353, 433, etc.).",
  "type": "object",
  "properties": {
    "id": {
      "type": "string",
      "format": "uuid",
      "description": "Server-assigned message UUID. Present on all server-originated messages."
    },
    "command": {
      "type": "string",
      "description": "IRC command name (PRIVMSG, JOIN, NICK, etc.) or three-digit numeric reply code (001, 353, 433, etc.).",
      "examples": ["PRIVMSG", "JOIN", "001", "353", "433"]
    },
    "from": {
      "type": "string",
      "description": "Source — nick for user messages, server name for server messages. Equivalent to IRC prefix."
    },
    "to": {
      "type": "string",
      "description": "Target — channel (#name) or nick. Equivalent to first IRC parameter for most commands."
    },
    "params": {
      "type": "array",
      "items": { "type": "string" },
      "description": "Additional parameters (used primarily by numeric replies). Equivalent to IRC middle parameters."
    },
    "body": {
      "oneOf": [
        {
          "type": "array",
          "items": { "type": "string" },
          "description": "Array of strings (one per line for text messages)."
        },
        {
          "type": "object",
          "description": "Structured data (e.g. PUBKEY key material).",
          "additionalProperties": true
        }
      ],
      "description": "Message body. MUST be an array or object, never a raw string. Arrays represent lines of text; objects carry structured data. This enables deterministic canonicalization (RFC 8785 JCS) for signing."
    },
    "ts": {
      "type": "string",
      "format": "date-time",
      "description": "Server-assigned timestamp (ISO 8601). Not present in original IRC; added for HTTP transport."
    },
    "meta": {
      "type": "object",
      "description": "Extensible metadata. Used for signatures (meta.sig, meta.alg), hashes (meta.hash), and client extensions.",
      "properties": {
        "sig": {
          "type": "string",
          "description": "Base64-encoded cryptographic signature over the canonical message form."
        },
        "alg": {
          "type": "string",
          "description": "Signature algorithm (e.g. 'ed25519')."
        },
        "hash": {
          "type": "string",
          "description": "Hash of the canonical message form (e.g. 'sha256:base64...')."
        }
      },
      "additionalProperties": true
    }
  },
  "required": ["command"]
}