Everything is a Worker

Why this change

iii is built on three primitives: Workers, Functions, and Triggers. Every concept in the system maps to one of these:

Workers are long-running processes that connect to the engine and provide capabilities — HTTP serving, queue processing, cron scheduling, state management, stream handling, and anything else the engine needs to operate.
Functions are units of work. A worker registers functions, and any other worker (or the engine itself) can invoke them by ID.
Triggers are the rules that cause functions to fire — an HTTP request, a cron schedule, a queue message, a state change.

Before this release, the engine-internal components that provide capabilities (HTTP, queues, cron, etc.) were called “modules”. Meanwhile, the remote SDK processes that register functions were called “workers”. This created a confusing split: two different names for things that serve the same role — connecting to the engine and doing work. Modules are workers. They run alongside the engine, register functions, react to triggers, and provide capabilities to the rest of the system. The only difference was the name. By renaming modules to workers, every component in the system uses the same vocabulary. The engine config lists workers:. The SDK connects workers. The docs describe workers. There is one concept, one name, and one mental model. The previous Worker struct (representing a connected SDK runtime over WebSocket) has been renamed to WorkerConnection to avoid collision.

What changed

Config YAML

The top-level modules: key is now workers:, and each entry uses name: with a short identifier instead of class: with a Rust-style path.

# Before
modules:
  - class: modules::stream::StreamModule
    config:
      port: 3112

# After
workers:
  - name: iii-stream
    config:
      port: 3112

The modules: key is still accepted for backward compatibility, but workers: is the canonical form going forward.

Worker name mapping

Old `class:` value	New `name:` value
`modules::worker::WorkerModule`	`iii-worker-manager`
`modules::stream::StreamModule`	`iii-stream`
`modules::state::StateModule`	`iii-state`
`modules::api::RestApiModule`	`iii-http`
`modules::pubsub::PubSubModule`	`iii-pubsub`
`modules::observability::OtelModule`	`iii-observability`
`modules::queue::QueueModule`	`iii-queue`
`modules::http_functions::HttpFunctionsModule`	`iii-http-functions`
`modules::cron::CronModule`	`iii-cron`
`modules::shell::ExecModule`	`iii-exec`
`modules::bridge_client::BridgeClientModule`	`iii-bridge`

Adapter name mapping

Adapter entries inside config.adapter also switched from class: to name: with short identifiers:

Old adapter `class:`	New adapter `name:`
`modules::stream::adapters::KvStore`	`kv`
`modules::stream::adapters::RedisAdapter`	`redis`
`modules::stream::adapters::Bridge`	`bridge`
`modules::state::adapters::KvStore`	`kv`
`modules::state::adapters::RedisAdapter`	`redis`
`modules::state::adapters::Bridge`	`bridge`
`modules::pubsub::LocalAdapter`	`local`
`modules::pubsub::RedisAdapter`	`redis`
`modules::queue::BuiltinQueueAdapter`	`builtin`
`modules::queue::RedisAdapter`	`redis`
`modules::queue::RabbitMQAdapter`	`rabbitmq`
`modules::queue::adapters::Bridge`	`bridge`
`modules::cron::KvCronAdapter`	`kv`
`modules::cron::RedisCronAdapter`	`redis`

Full config example

Before
After

modules:
  - class: modules::stream::StreamModule
    config:
      port: 3112
      adapter:
        class: modules::stream::adapters::KvStore
        config:
          store_method: file_based
          file_path: ./data/stream_store

  - class: modules::state::StateModule
    config:
      adapter:
        class: modules::state::adapters::KvStore
        config:
          store_method: file_based
          file_path: ./data/state_store.db

  - class: modules::api::RestApiModule
    config:
      port: 3111

  - class: modules::observability::OtelModule
    config:
      enabled: true

  - class: modules::queue::QueueModule
    config:
      adapter:
        class: modules::queue::BuiltinQueueAdapter

  - class: modules::pubsub::PubSubModule
    config:
      adapter:
        class: modules::pubsub::LocalAdapter

  - class: modules::cron::CronModule
    config:
      adapter:
        class: modules::cron::KvCronAdapter

workers:
  - name: iii-stream
    config:
      port: 3112
      adapter:
        name: kv
        config:
          store_method: file_based
          file_path: ./data/stream_store

  - name: iii-state
    config:
      adapter:
        name: kv
        config:
          store_method: file_based
          file_path: ./data/state_store.db

  - name: iii-http
    config:
      port: 3111

  - name: iii-observability
    config:
      enabled: true

  - name: iii-queue
    config:
      adapter:
        name: builtin

  - name: iii-pubsub
    config:
      adapter:
        name: local

  - name: iii-cron
    config:
      adapter:
        name: kv

Rust API

Crate module path

The modules Rust module has been renamed to workers, and the trait definition file moved from module.rs to traits.rs.

// Before
use iii::modules::config::EngineBuilder;
use iii::modules::module::Module;
use iii::modules::registry::ModuleRegistration;

// After
use iii::workers::config::EngineBuilder;  // also re-exported as iii::EngineBuilder
use iii::workers::traits::Worker;
use iii::workers::registry::WorkerRegistration;

Trait renames

Before	After
`trait Module`	`trait Worker`
`trait ConfigurableModule`	`trait ConfigurableWorker`
`Module::make_module()`	`Worker::make_worker()`
`Module::create() -> Box<dyn Module>`	`Worker::create() -> Box<dyn Worker>`
`ConfigurableModule::DEFAULT_ADAPTER_CLASS`	`ConfigurableWorker::DEFAULT_ADAPTER_NAME`
`ConfigurableModule::default_adapter_class()`	`ConfigurableWorker::default_adapter_name()`
`ConfigurableModule::adapter_class_from_config()`	`ConfigurableWorker::adapter_name_from_config()`

Type alias and struct renames

Before	After
`ModuleFuture`	`WorkerFuture`
`ModuleFactory`	`WorkerFactory`
`ModuleInfo`	`WorkerInfo`
`ModuleRegistry`	`WorkerRegistry`
`ModuleEntry`	`WorkerEntry`
`ModuleRegistration`	`WorkerRegistration`

Macro renames

Before	After
`register_module!(class, Type, ...)`	`register_worker!(name, Type, ...)`

EngineBuilder API

Before	After
`EngineBuilder::add_module(class, config)`	`EngineBuilder::add_worker(name, config)`
`EngineBuilder::register_module::<M>(class)`	`EngineBuilder::register_worker::<M>(name)`

Implementation struct renames

Before	After
`WorkerModule`	`WorkerManager`
`StreamCoreModule`	`StreamWorker`
`StateCoreModule`	`StateWorker`
`RestApiCoreModule`	`HttpWorker`
`PubSubCoreModule`	`PubSubWorker`
`OtelModule`	`ObservabilityWorker`
`QueueCoreModule`	`QueueWorker`
`HttpFunctionsModule`	`HttpFunctionsWorker`
`CronCoreModule`	`CronWorker`
`ExecCoreModule`	`ExecWorker`
`BridgeClientModule`	`BridgeClientWorker`
`TelemetryModule`	`TelemetryWorker`
`EngineFunctionsModule`	`EngineFunctionsWorker`
`ExternalModule`	`ExternalWorker`

WorkerConnection (was Worker)

The Worker struct that represented a connected remote SDK runtime has been renamed to WorkerConnection and moved to a separate module.

Before	After
`crate::workers::Worker`	`crate::worker_connections::WorkerConnection`
`crate::workers::WorkerRegistry`	`crate::worker_connections::WorkerConnectionRegistry`
`crate::workers::WorkerStatus`	`crate::worker_connections::WorkerConnectionStatus`
`crate::workers::WorkerTelemetryMeta`	`crate::worker_connections::WorkerConnectionTelemetryMeta`

Migration examples

Custom worker

Before
After

use iii::modules::module::Module;

pub struct MyModule { /* ... */ }

#[async_trait]
impl Module for MyModule {
    fn name(&self) -> &'static str { "MyModule" }
    async fn create(engine: Arc<Engine>, config: Option<Value>) -> anyhow::Result<Box<dyn Module>> {
        Ok(Box::new(MyModule { /* ... */ }))
    }
    async fn initialize(&self) -> anyhow::Result<()> { Ok(()) }
}

iii::register_module!("my::custom::Module", MyModule, enabled_by_default = true);

use iii::workers::traits::Worker;

pub struct MyWorker { /* ... */ }

#[async_trait]
impl Worker for MyWorker {
    fn name(&self) -> &'static str { "MyWorker" }
    async fn create(engine: Arc<Engine>, config: Option<Value>) -> anyhow::Result<Box<dyn Worker>> {
        Ok(Box::new(MyWorker { /* ... */ }))
    }
    async fn initialize(&self) -> anyhow::Result<()> { Ok(()) }
}

iii::register_worker!("iii-my-custom", MyWorker, enabled_by_default = true);

Custom adapter

Before
After

iii::register_adapter!(
    <MyAdapterRegistration>
    "modules::my_worker::MyAdapter",
    make_adapter
);

iii::register_adapter!(
    <MyAdapterRegistration>
    name: "my-adapter",
    make_adapter
);

Migration checklist

Rename modules: to workers: in all config YAML files
Replace class: with name: using the new short identifiers (see tables above)
Replace adapter class: with name: using short identifiers (kv, redis, builtin, etc.)
Update Rust imports from iii::modules:: to iii::workers::
Update iii::modules::module::Module to iii::workers::traits::Worker
Replace register_module! with register_worker!
Replace add_module() / register_module() on EngineBuilder with add_worker() / register_worker()
Rename any *Module / *CoreModule struct references to the new *Worker / *Manager names
Update crate::workers::Worker references to crate::worker_connections::WorkerConnection

Changelog

0.11.0

Everything is a Worker

Why this change

What changed

Config YAML

Worker name mapping

Adapter name mapping

Full config example

Rust API

Crate module path

Trait renames

Type alias and struct renames

Macro renames

EngineBuilder API

Implementation struct renames

WorkerConnection (was Worker)

Migration examples

Custom worker

Custom adapter

Migration checklist

Changelog

0.11.0

​Why this change

​What changed

​Config YAML

​Worker name mapping

​Adapter name mapping

​Full config example

​Rust API

​Crate module path

​Trait renames

​Type alias and struct renames

​Macro renames

​EngineBuilder API

​Implementation struct renames

​WorkerConnection (was Worker)

​Migration examples

​Custom worker

​Custom adapter

​Migration checklist

Why this change

What changed

Config YAML

Worker name mapping

Adapter name mapping

Full config example

Rust API

Crate module path

Trait renames

Type alias and struct renames

Macro renames

EngineBuilder API

Implementation struct renames

WorkerConnection (was Worker)

Migration examples

Custom worker

Custom adapter

Migration checklist