{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://go-sip.local/contracts/proposals/task-discovery-v0.4-proposal.schema.json",
  "title": "Project-local restart snapshot and live assignment changes; SaaS compatibility unverified",
  "oneOf": [
    {"$ref": "#/$defs/snapshot_page"},
    {"$ref": "#/$defs/change_page"},
    {"$ref": "#/$defs/error_response"}
  ],
  "$defs": {
    "dispatcher_id": {"$ref": "https://go-sip.local/contracts/proposals/task-discovery-v0.3-proposal.schema.json#/$defs/dispatcher_id"},
    "cursor": {"$ref": "https://go-sip.local/contracts/proposals/task-discovery-v0.3-proposal.schema.json#/$defs/cursor"},
    "task": {"$ref": "https://go-sip.local/contracts/proposals/task-discovery-v0.3-proposal.schema.json#/$defs/task"},
    "snapshot_page": {
      "type": "object", "additionalProperties": false,
      "required": ["schema_version", "mode", "dispatcher_id", "snapshot_id", "watermark", "next_page_token", "tasks"],
      "properties": {
        "schema_version": {"const": "task-discovery.v0.4-proposal"},
        "mode": {"const": "snapshot"},
        "dispatcher_id": {"$ref": "#/$defs/dispatcher_id"},
        "snapshot_id": {"type": "string", "format": "uuid", "pattern": "^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$"},
        "watermark": {"$ref": "#/$defs/cursor"},
        "next_page_token": {"type": ["string", "null"], "minLength": 1, "maxLength": 256},
        "tasks": {"type": "array", "maxItems": 256, "items": {"$ref": "#/$defs/task"}}
      },
      "$comment": "Every page has identical snapshot_id and watermark; null next_page_token ends this consistent complete inventory. No task appears twice, and removed tasks are omitted only from the complete inventory. Server retains stopped tasks with not-yet-retired queues. Semantic client checks enforce consistency."
    },
    "change_page": {
      "type": "object", "additionalProperties": false,
      "required": ["schema_version", "mode", "dispatcher_id", "next_cursor", "tasks"],
      "properties": {
        "schema_version": {"const": "task-discovery.v0.4-proposal"},
        "mode": {"const": "changes"},
        "dispatcher_id": {"$ref": "#/$defs/dispatcher_id"},
        "next_cursor": {"$ref": "#/$defs/cursor"},
        "tasks": {"type": "array", "maxItems": 256, "items": {"$ref": "#/$defs/task"}}
      },
      "$comment": "Live-only event cursor; ordered complete event positions per dispatcher, no server expiry while the process is running. Removed tombstones are explicit; status values are not online control commands. A nonempty page advances the cursor, and an empty page repeats it."
    },
    "error_response": {
      "type": "object", "additionalProperties": false,
      "required": ["schema_version", "resource", "error"],
      "properties": {
        "schema_version": {"const": "task-discovery.v0.4-proposal"},
        "resource": {"const": "error"},
        "error": {
          "type": "object", "additionalProperties": false,
          "required": ["code", "message"],
          "properties": {
            "code": {"enum": ["invalid_request", "invalid_page_token", "snapshot_unavailable", "unauthorized", "dispatcher_not_authorized", "service_unavailable"]},
            "message": {"type": "string", "minLength": 1, "maxLength": 256}
          }
        }
      }
    }
  }
}