Restate Invocation Structure

{
  "name": "Invocation",
  "description": "Structure documentation for a Restate durable invocation with exactly-once execution semantics",
  "fields": [
    {
      "name": "id",
      "type": "string",
      "required": true,
      "description": "Unique invocation identifier"
    },
    {
      "name": "target",
      "type": "string",
      "required": true,
      "description": "Fully qualified target in ServiceName/handlerName format"
    },
    {
      "name": "target_service_name",
      "type": "string",
      "required": false,
      "description": "Name of the target service"
    },
    {
      "name": "target_handler_name",
      "type": "string",
      "required": false,
      "description": "Name of the target handler"
    },
    {
      "name": "target_service_key",
      "type": "string|null",
      "required": false,
      "description": "Virtual object key (null for plain services)"
    },
    {
      "name": "status",
      "type": "enum",
      "required": true,
      "description": "Invocation execution state",
      "values": ["pending", "ready", "running", "backing-off", "suspended", "completed"]
    },
    {
      "name": "created_at",
      "type": "string (date-time)",
      "required": false,
      "description": "ISO 8601 creation timestamp"
    },
    {
      "name": "modified_at",
      "type": "string (date-time)",
      "required": false,
      "description": "ISO 8601 last modification timestamp"
    },
    {
      "name": "trace_id",
      "type": "string",
      "required": false,
      "description": "Distributed trace identifier"
    },
    {
      "name": "deployment_id",
      "type": "string",
      "required": false,
      "description": "Deployment handling the invocation"
    },
    {
      "name": "retry_count",
      "type": "integer",
      "required": false,
      "description": "Number of retries attempted"
    },
    {
      "name": "last_failure",
      "type": "string|null",
      "required": false,
      "description": "Last failure description"
    },
    {
      "name": "next_retry_at",
      "type": "string|null (date-time)",
      "required": false,
      "description": "Scheduled retry timestamp"
    }
  ]
}