$worker

iii-queue

v0.11.6-next.4

Queue worker for async job processing with named queues, retries, and dead-letter support.

engine module

baked into the iii engine; no separate install required.

agent-ready brief for v0.11.6-next.4

install + config + dependencies + readme + api reference, all in one place. fetch as agent-context.md for an llm to consume.

full markdown

open as agent-context.md

the same content rendered as discrete blocks below is exposed as a single markdown document at /workers/iii-queue.md?version=0.11.6-next.4. paste it into an llm prompt or pipe it through curl from a worker.

install

$iii worker add iii-queue@0.11.6-next.4

configuration

iii-config.yaml

- adapter:
    name: builtin

dependencies

no dependencies for v0.11.6-next.4

readme

README.md

iii-queue

Asynchronous job processing with named queues, retries, and dead-letter support.

Supports two modes:

Topic-based queues — register a consumer per topic, emit events via iii::durable::publish. Fan-out: every distinct function subscribed to a topic receives a copy of each message.
Named queues — define queues in config, then enqueue function calls via TriggerAction.Enqueue. No trigger registration needed.

Sample Configuration

- name: iii-queue
  config:
    queue_configs:
      default:
        max_retries: 5
        concurrency: 5
        type: standard
      payment:
        max_retries: 10
        concurrency: 2
        type: fifo
        message_group_field: transaction_id
    adapter:
      name: builtin
      config:
        store_method: file_based
        file_path: ./data/queue_store

Configuration

Field	Type	Description
`queue_configs`	map[string, FunctionQueueConfig]	Map of named queue configurations. Each key is the queue name.
`adapter`	Adapter	Transport adapter. Defaults to `builtin`.

Queue Configuration (`queue_configs` entries)

Field	Type	Description
`max_retries`	u32	Maximum delivery attempts before routing to DLQ. Defaults to `3`.
`concurrency`	u32	Maximum jobs processed simultaneously. Defaults to `10`. FIFO queues override this to `prefetch=1`.
`type`	string	`standard` (concurrent) or `fifo` (ordered within a message group).
`message_group_field`	string	Required for `fifo`. JSON field whose value determines the ordering group.
`backoff_ms`	u64	Base retry backoff in milliseconds. Exponential: `backoff_ms × 2^(attempt−1)`. Defaults to `1000`.
`poll_interval_ms`	u64	Worker poll interval in milliseconds. Defaults to `100`.

Queue Modes

When to use which

	Topic-based	Named queues
Producer	`trigger({ function_id: 'iii::durable::publish', payload: { topic, data } })`	`trigger({ function_id, payload, action: TriggerAction.Enqueue({ queue }) })`
Consumer	`registerTrigger({ type: 'durable:subscriber', config: { topic } })`	No registration — function is the target
Delivery	Fan-out: each subscribed function gets every message; replicas compete	Single target function per enqueue call
Config	Optional `queue_config` on trigger	`queue_configs` in `iii-config.yaml`
Use case	Durable pub/sub with retries and fan-out	Direct function invocation with retries, FIFO, DLQ

Standard vs FIFO Queues

Dimension	Standard	FIFO
Processing model	Up to `concurrency` jobs in parallel	One job at a time (prefetch=1)
Ordering	No guarantees	Strictly ordered within a message group
`message_group_field`	Not required	Required — must be present and non-null in every payload
Throughput	High	Lower — trades throughput for ordering
Use cases	Email sends, image processing, notifications	Payments, ledger entries, state machines
Retries	Retried independently, other jobs continue	Retried inline — blocks the queue until success or DLQ

Adapters

builtin

Built-in in-process queue. No external dependencies. Suitable for single-instance deployments.

name: builtin
config:
  store_method: file_based   # in_memory | file_based
  file_path: ./data/queue_store

redis

Uses Redis Pub/Sub for topic-based queues. Supports multi-instance deployments.

Note: The Redis adapter supports publishing to named queues but does not implement named queue consumption, retries, or dead-letter queues. For full named queue support in multi-instance deployments, use RabbitMQ.

name: redis
config:
  redis_url: ${REDIS_URL:redis://localhost:6379}

rabbitmq

Uses RabbitMQ for durable delivery, retries, and dead-letter queues across multiple engine instances.

name: rabbitmq
config:
  amqp_url: ${RABBITMQ_URL:amqp://localhost:5672}

Adapter Comparison

	builtin	rabbitmq	redis
Retries	Yes	Yes	No
Dead-letter queue	Yes	Yes	No
FIFO ordering	Yes	Yes	No
Named queue consumption	Yes	Yes	No (publish only)
Topic-based pub/sub	Yes	Yes	Yes
Multi-instance	No	Yes	Yes
External dependency	None	RabbitMQ	Redis

Scenario	Recommended Adapter
Local development	`builtin` (`in_memory`)
Single-instance production	`builtin` (`file_based`)
Multi-instance production	`rabbitmq`

Builtin Functions

`iii::durable::publish`

Publishes a message to a topic-based queue. Fanned out to every distinct subscribed function.

Field	Type	Description
`topic`	string	The topic to publish to (required).
`data`	any	The payload delivered to each subscribed function.

`iii::queue::redrive`

Moves all messages from a named queue's dead-letter queue back to the main queue.

Field	Type	Description
`queue`	string	The named queue whose DLQ should be redriven.

Returns: queue (string), redriven (number)

iii trigger \
  --function-id='iii::queue::redrive' \
  --payload='{"queue": "payment"}'

api reference (json)

agent-api-reference.json

{
  "functions": [
    {
      "description": "Browse DLQ messages",
      "metadata": {},
      "name": "engine::queue::dlq_messages",
      "request_schema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "title": "AnyValue"
      },
      "response_schema": {}
    },
    {
      "description": "List DLQ topics with counts",
      "metadata": {},
      "name": "engine::queue::dlq_topics",
      "request_schema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "title": "AnyValue"
      },
      "response_schema": {}
    },
    {
      "description": "List all queue topics",
      "metadata": {},
      "name": "engine::queue::list_topics",
      "request_schema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "title": "AnyValue"
      },
      "response_schema": {}
    },
    {
      "description": "Get stats for a queue topic",
      "metadata": {},
      "name": "engine::queue::topic_stats",
      "request_schema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "title": "AnyValue"
      },
      "response_schema": {}
    },
    {
      "description": "Enqueue a message",
      "metadata": {},
      "name": "iii::durable::publish",
      "request_schema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "properties": {
          "data": true,
          "topic": {
            "type": "string"
          }
        },
        "required": [
          "data",
          "topic"
        ],
        "title": "QueueInput",
        "type": "object"
      },
      "response_schema": {}
    },
    {
      "description": "Discard (purge) a single DLQ message by ID",
      "metadata": {},
      "name": "iii::queue::discard_message",
      "request_schema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "properties": {
          "message_id": {
            "type": "string"
          },
          "queue": {
            "type": "string"
          }
        },
        "required": [
          "message_id",
          "queue"
        ],
        "title": "RedriveSingleInput",
        "type": "object"
      },
      "response_schema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "properties": {
          "message_id": {
            "type": "string"
          },
          "queue": {
            "type": "string"
          },
          "redriven": {
            "format": "uint64",
            "minimum": 0,
            "type": "integer"
          }
        },
        "required": [
          "message_id",
          "queue",
          "redriven"
        ],
        "title": "RedriveSingleResult",
        "type": "object"
      }
    },
    {
      "description": "Redrive all DLQ messages back to the main queue",
      "metadata": {},
      "name": "iii::queue::redrive",
      "request_schema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "properties": {
          "queue": {
            "type": "string"
          }
        },
        "required": [
          "queue"
        ],
        "title": "RedriveInput",
        "type": "object"
      },
      "response_schema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "properties": {
          "queue": {
            "type": "string"
          },
          "redriven": {
            "format": "uint64",
            "minimum": 0,
            "type": "integer"
          }
        },
        "required": [
          "queue",
          "redriven"
        ],
        "title": "RedriveResult",
        "type": "object"
      }
    },
    {
      "description": "Redrive a single DLQ message by ID back to the main queue",
      "metadata": {},
      "name": "iii::queue::redrive_message",
      "request_schema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "properties": {
          "message_id": {
            "type": "string"
          },
          "queue": {
            "type": "string"
          }
        },
        "required": [
          "message_id",
          "queue"
        ],
        "title": "RedriveSingleInput",
        "type": "object"
      },
      "response_schema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "properties": {
          "message_id": {
            "type": "string"
          },
          "queue": {
            "type": "string"
          },
          "redriven": {
            "format": "uint64",
            "minimum": 0,
            "type": "integer"
          }
        },
        "required": [
          "message_id",
          "queue",
          "redriven"
        ],
        "title": "RedriveSingleResult",
        "type": "object"
      }
    }
  ],
  "triggers": [
    {
      "description": "Queue core module",
      "invocation_schema": {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "properties": {
          "condition_function_id": {
            "description": "Optional function ID to evaluate before invoking handler",
            "type": [
              "string",
              "null"
            ]
          },
          "queue_config": {
            "description": "Queue-specific subscriber configuration"
          },
          "topic": {
            "description": "Queue topic to subscribe to",
            "type": "string"
          }
        },
        "required": [
          "topic"
        ],
        "title": "QueueTriggerConfig",
        "type": "object"
      },
      "metadata": {},
      "name": "durable:subscriber",
      "return_schema": {}
    }
  ]
}

iii-queue

full markdown

install

configuration

dependencies

readme

iii-queue

Sample Configuration

Configuration

Queue Configuration (queue_configs entries)

Queue Modes

When to use which

Standard vs FIFO Queues

Adapters

builtin

redis

rabbitmq

Adapter Comparison

Builtin Functions

iii::durable::publish

iii::queue::redrive

api reference (json)

Queue Configuration (`queue_configs` entries)

`iii::durable::publish`

`iii::queue::redrive`