Rust SDK - iii

Installation

cargo add iii-sdk

Initialization

register_worker

Register the worker with a iii instance, returns a connected worker client. The WebSocket connection is established automatically in a dedicated background thread with its own tokio runtime. Call IIIClient::shutdown before the end of main to cleanly stop the connection and join the background thread. In Rust the process exits when main returns, terminating all threads, so shutdown() must be called while main is still running. Signature

register_worker(address: &str, options: InitOptions) -> IIIClient

Parameters
Example

address

&str

required

WebSocket URL of the III engine (e.g. ws://localhost:49134).

options

InitOptions

required

Configuration for worker metadata and OTel.

Show `InitOptions` fields

metadata

Option<iii::WorkerMetadata>

Custom worker metadata. Auto-detected if None.

headers

Option<HashMap<String, String>>

Custom HTTP headers sent during the WebSocket handshake.

otel

Option<iii_helpers::observability::OtelConfig>

OpenTelemetry configuration.

use iii_sdk::{register_worker, InitOptions};

let worker = register_worker("ws://localhost:49134", InitOptions::default());
// register functions, handle events, etc.
worker.shutdown(); // cleanly stops the connection thread

Methods

register_trigger

Bind a trigger configuration to a registered function. Signature

register_trigger(input: RegisterTriggerInput) -> Result<Trigger, Error>

Parameters
Example

input

RegisterTriggerInput

required

Trigger registration input with trigger_type, function_id, and config.

Hide `RegisterTriggerInput` fields

trigger_type

String

required

Identifier of the registered trigger type this trigger uses (e.g. storage::object-created, http).

function_id

String

required

ID of the function this trigger invokes when it fires.

config

Value

required

Trigger-type-specific configuration, matching the shape the trigger type expects.

metadata

Option<Value>

Arbitrary user-specifiable metadata supplied to the triggered handler function on every invocation.

let trigger = worker.register_trigger(RegisterTriggerInput {
    trigger_type: "http".to_string(),
    function_id: "greet".to_string(),
    config: json!({ "api_path": "/greet", "http_method": "GET" }),
    metadata: None,
})?;
// Later...
trigger.unregister();

register_function

Register a function with the engine. Argument order matches the Node and Python SDKs: (id, registration). Signature

register_function(id: impl Into<String>, registration: RegisterFunction) -> FunctionRef

Parameters
Example

impl Into<String>

required

Unique identifier for the function.

registration

RegisterFunction

required

Built via [RegisterFunction::new], [RegisterFunction::new_async], or [RegisterFunction::http]. Chain .description(...), .metadata(...), .request_format(...), .response_format(...) as needed.

Show `RegisterFunction` fields

description

fn(desc: impl Into<String>) -> Self

required

Set the function description.

http

fn(config: HttpInvocationConfig) -> Self

required

Create a registration for an HTTP-invoked function (Lambda, Cloudflare Workers, etc.). No local handler runs.

metadata

fn(meta: Value) -> Self

required

Set function metadata.

new

fn(f: F) -> Self

required

Create a registration for a sync typed function.

new_async

fn(f: F) -> Self

required

Create a registration for an async typed function.

request_format

fn(schema: Value) -> Self

required

Set the request format schema. Overrides any auto-extracted schema.

response_format

fn(schema: Value) -> Self

required

Set the response format schema. Overrides any auto-extracted schema.

use iii_sdk::{register_worker, InitOptions, Error, RegisterFunction};
use serde::{Deserialize, Serialize};
use schemars::JsonSchema;

#[derive(Deserialize, JsonSchema)]
struct Input { name: String }
#[derive(Serialize, JsonSchema)]
struct Output { message: String }

async fn greet(input: Input) -> Result<Output, Error> {
    Ok(Output { message: format!("Hello, {}!", input.name) })
}

let worker = register_worker("ws://localhost:49134", InitOptions::default());
worker.register_function(
    "greetings::greet",
    RegisterFunction::new_async(greet).description("Greets a user"),
);

trigger

Invoke a remote function. The routing behavior depends on the action field of the request:

No action: synchronous, waits for the function to return.
TriggerAction::Enqueue: async via named queue.
TriggerAction::Void: fire-and-forget.

Signature

async trigger(request: impl Into<TriggerRequestWithMetadata>) -> Result<Value, Error>

Parameters
Example

request

impl Into<TriggerRequestWithMetadata>

required

Hide `TriggerRequest` fields

function_id

String

required

ID of the function to invoke.

payload

Value

required

Input data passed to the function.

action

Option<TriggerAction>

Sets how the trigger is routed. None for a synchronous request/response. Set a routing scheme otherwise (e.g. TriggerAction::Enqueue { .. }, TriggerAction::Void).

timeout_ms

Option<u64>

Override the default invocation timeout, in milliseconds.

metadata

fn(metadata: Value) -> TriggerRequestWithMetadata

required

Attach per-invocation metadata without adding a required field to TriggerRequest struct literals.

// Synchronous
let result = worker.trigger(TriggerRequest {
    function_id: "greet".to_string(),
    payload: json!({"name": "World"}),
    action: None,
    timeout_ms: None,
}).await?;

// Fire-and-forget
worker.trigger(TriggerRequest {
    function_id: "notify".to_string(),
    payload: json!({}),
    action: Some(TriggerAction::Void),
    timeout_ms: None,
}).await?;

// Enqueue (the queue must be declared in the iii-queue worker's
// queue_configs)
let receipt = worker.trigger(TriggerRequest {
    function_id: "iii::durable::publish".to_string(),
    payload: json!({"topic": "test"}),
    action: Some(TriggerAction::Enqueue { queue: "test".to_string() }),
    timeout_ms: None,
}).await?;

// Metadata
worker.trigger(
    TriggerRequest {
        function_id: "audit::write".to_string(),
        payload: json!({"event": "checkout"}),
        action: Some(TriggerAction::Void),
        timeout_ms: None,
    }
    .metadata(json!({"tenant": "acme"})),
).await?;

register_trigger_type

Register a custom trigger type with the engine. Returns a TriggerTypeRef handle that can register triggers and functions with compile-time validated types. Signature

register_trigger_type(trigger_type: RegisterTriggerType<H, C, R>) -> TriggerTypeRef<C, R>

Parameters
Example

trigger_type

RegisterTriggerType<H, C, R>

required

Show `RegisterTriggerType` fields

call_request_format

fn() -> RegisterTriggerType<H, C, T>

required

Set the call request format schema from a type. Changes R, enabling compile-time validation on TriggerTypeRef::register_function.

new

fn(id: impl Into<String>, description: impl Into<String>, handler: H) -> Self

required

trigger_request_format

fn() -> RegisterTriggerType<H, T, R>

required

Set the trigger request format schema from a type. Changes C, enabling compile-time validation on TriggerTypeRef::register_trigger.

let my_trigger = worker.register_trigger_type(
    RegisterTriggerType::new("my-trigger", "My custom trigger", MyHandler)
        .trigger_request_format::<MyConfig>()
        .call_request_format::<MyRequest>(),
);

// Compile-time safe: config must be MyConfig, function input must be MyRequest
my_trigger.register_function("my::handler", |req: MyRequest| -> Result<serde_json::Value, iii_sdk::Error> {
    Ok(serde_json::json!({ "data": req.data }))
});
my_trigger.register_trigger("my::handler", MyConfig { url: "/hook".into() });

unregister_trigger_type

Unregister a previously registered trigger type. Signature

unregister_trigger_type(id: impl Into<String>)

Parameters
Example

impl Into<String>

required

worker.unregister_trigger_type("cron");

get_connection_state

Get the current connection state. Signature

get_connection_state() -> IIIConnectionState

Example

if worker.get_connection_state() != IIIConnectionState::Connected {
    eprintln!("engine not reachable yet");
}

shutdown

Shutdown the III client and wait for the connection thread to finish. This stops the connection loop, sends a shutdown signal, and joins the background connection thread. OpenTelemetry is flushed inside the connection thread before it exits. Signature

shutdown()

Example

worker.shutdown();

shutdown_async

Shutdown the III client. This stops the connection loop and sends a shutdown signal, but it does not join connection_thread. This method returns without waiting for run_connection() to finish, making it safe to call from an async context without stalling the executor; shutdown blocks and joins the thread. The OpenTelemetry flush (telemetry::shutdown_otel()) still runs inside the connection thread after run_connection() returns, so it may not complete unless shutdown is used to join the thread. Signature

async shutdown_async()

Example

worker.shutdown_async().await;

Types

iii_sdk

EnqueueResult · InitOptions · RegisterFunction · RegisterTriggerType · TelemetryOptions

EnqueueResult

Result returned when a function is invoked with TriggerAction.Enqueue.

Name	Type	Required	Description
`message_receipt_id`	`String`	Yes	Unique receipt ID for the enqueued message.

InitOptions

Configuration options passed to register_worker.

Name	Type	Required	Description
`metadata`	Option<iii::`WorkerMetadata`>	No	Custom worker metadata. Auto-detected if `None`.
`headers`	`Option<HashMap<String, String>>`	No	Custom HTTP headers sent during the WebSocket handshake.
`otel`	`Option<iii_helpers::observability::OtelConfig>`	No	OpenTelemetry configuration.

RegisterFunction

Function registration builder. The function ID is supplied separately at registration time via IIIClient::register_function, RegisterFunction only carries the handler and optional metadata. Constructors:

RegisterFunction::new: sync function. Accepts both typed handlers (schemas auto-extracted via schemars) and Fn(Value, Option<Value>) -> Result<Value, Error> closures. The second argument is the per-invocation metadata sidecar and is None when absent.
RegisterFunction::new_async: async equivalent of new.
RegisterFunction::http: function invoked over HTTP (Lambda, Cloudflare Workers, etc.).

Builder methods (all consume self):

description
metadata
request_format: overrides any auto-extracted schema.
response_format: overrides any auto-extracted schema.

Name	Type	Required	Description
`description`	`fn(desc: impl Into<String>) -> Self`	Yes	Set the function description.
`http`	`fn(config: HttpInvocationConfig) -> Self`	Yes	Create a registration for an HTTP-invoked function (Lambda, Cloudflare Workers, etc.). No local handler runs.
`metadata`	`fn(meta: Value) -> Self`	Yes	Set function metadata.
`new`	`fn(f: F) -> Self`	Yes	Create a registration for a sync typed function.
`new_async`	`fn(f: F) -> Self`	Yes	Create a registration for an async typed function.
`request_format`	`fn(schema: Value) -> Self`	Yes	Set the request format schema. Overrides any auto-extracted schema.
`response_format`	`fn(schema: Value) -> Self`	Yes	Set the response format schema. Overrides any auto-extracted schema.

RegisterTriggerType

Builder for registering a custom trigger type with optional format schemas. Type parameters:

C tracks the trigger registration type (set via .trigger_request_format::<T>())
R tracks the call request type (set via .call_request_format::<T>())

Both default to Value (untyped) and change when the respective builder method is called. This allows IIIClient::register_trigger_type to return a TriggerTypeRef<C, R> with compile-time safety for both config and function input types.

Name	Type	Required	Description
`call_request_format`	fn() -> `RegisterTriggerType`<H, C, T>	Yes	Set the call request format schema from a type. Changes `R`, enabling compile-time validation on `TriggerTypeRef::register_function`.
`new`	`fn(id: impl Into<String>, description: impl Into<String>, handler: H) -> Self`	Yes	-
`trigger_request_format`	fn() -> `RegisterTriggerType`<H, T, R>	Yes	Set the trigger request format schema from a type. Changes `C`, enabling compile-time validation on `TriggerTypeRef::register_trigger`.

TelemetryOptions

Worker metadata reported to the engine (language, framework, project).

Name	Type	Required	Description
`language`	`Option<String>`	No	Programming language of the worker.
`project_name`	`Option<String>`	No	Name of the project this worker belongs to.
`framework`	`Option<String>`	No	Framework name, if applicable.
`amplitude_api_key`	`Option<String>`	No	Amplitude API key for product analytics.

iii_sdk::builtin_triggers

CronCallRequest · CronTriggerConfig · HttpCallRequest · HttpMethod · HttpTriggerConfig · LogCallRequest · LogLevel · LogTriggerConfig · QueueTriggerConfig · StateCallRequest · StateEventType · StateTriggerConfig · SubscribeTriggerConfig

CronCallRequest

Name	Type	Required	Description
`trigger`	`String`	Yes	-
`job_id`	`String`	Yes	-
`scheduled_time`	`String`	Yes	-
`actual_time`	`String`	Yes	-

CronTriggerConfig

Name	Type	Required	Description
`expression`	`String`	Yes	Cron expression (6-field format: sec min hour day month weekday)
`condition_function_id`	`Option<String>`	No	Optional function ID to evaluate before invoking handler

HttpCallRequest

Name	Type	Required	Description
`query_params`	`HashMap<String, String>`	Yes	-
`path_params`	`HashMap<String, String>`	Yes	-
`headers`	`HashMap<String, String>`	Yes	-
`path`	`String`	Yes	-
`method`	`String`	Yes	-
`body`	`Value`	Yes	-

HttpMethod

Name	Type	Required	Description
`Get`	`unit`	Yes	-
`Post`	`unit`	Yes	-
`Put`	`unit`	Yes	-
`Delete`	`unit`	Yes	-
`Patch`	`unit`	Yes	-
`Head`	`unit`	Yes	-
`Options`	`unit`	Yes	-

HttpTriggerConfig

Name	Type	Required	Description
`api_path`	`String`	Yes	HTTP endpoint path (e.g. `/users/:id`)
`http_method`	Option<`HttpMethod`>	No	HTTP method (defaults to GET)
`condition_function_id`	`Option<String>`	No	Optional function ID to evaluate before invoking handler

LogCallRequest

Name	Type	Required	Description
`timestamp_unix_nano`	`u64`	Yes	-
`observed_timestamp_unix_nano`	`u64`	Yes	-
`severity_number`	`u32`	Yes	-
`severity_text`	`String`	Yes	-
`body`	`String`	Yes	-
`attributes`	`Value`	Yes	-
`trace_id`	`String`	Yes	-
`span_id`	`String`	Yes	-
`resource`	`Value`	Yes	-
`service_name`	`String`	Yes	-
`instrumentation_scope_name`	`String`	Yes	-
`instrumentation_scope_version`	`String`	Yes	-

LogLevel

Name	Type	Required	Description
`All`	`unit`	Yes	-
`Debug`	`unit`	Yes	-
`Info`	`unit`	Yes	-
`Warn`	`unit`	Yes	-
`Error`	`unit`	Yes	-

LogTriggerConfig

Name	Type	Required	Description
`level`	Option<`LogLevel`>	No	Minimum log level to trigger on

QueueTriggerConfig

Name	Type	Required	Description
`topic`	`String`	Yes	Queue topic to subscribe to
`condition_function_id`	`Option<String>`	No	Optional function ID to evaluate before invoking handler
`queue_config`	`Option<Value>`	No	Queue-specific subscriber configuration
`queue_config`	fn(config: impl Serialize) -> Result<Self, serde_json::`Error`>	Yes	-

StateCallRequest

Name	Type	Required	Description
`message_type`	`String`	Yes	-
`event_type`	`StateEventType`	Yes	-
`scope`	`String`	Yes	-
`key`	`String`	Yes	-
`old_value`	`Option<Value>`	No	-
`new_value`	`Value`	Yes	-

StateEventType

Name	Type	Required	Description
`Created`	`unit`	Yes	-
`Updated`	`unit`	Yes	-
`Deleted`	`unit`	Yes	-

StateTriggerConfig

Name	Type	Required	Description
`scope`	`Option<String>`	No	State scope to watch (exact match filter)
`key`	`Option<String>`	No	State key to watch (exact match filter)
`condition_function_id`	`Option<String>`	No	Optional function ID to evaluate before invoking handler

SubscribeTriggerConfig

Name	Type	Required	Description
`topic`	`String`	Yes	Topic to subscribe to
`condition_function_id`	`Option<String>`	No	Optional function ID to evaluate before invoking handler

iii_sdk::channel

Channel · ChannelReader · ChannelWriter · StreamChannelRef

Channel

A streaming channel pair for worker-to-worker data transfer.

Name	Type	Required	Description
`writer`	`ChannelWriter`	Yes	-
`reader`	`ChannelReader`	Yes	-
`writer_ref`	`StreamChannelRef`	Yes	-
`reader_ref`	`StreamChannelRef`	Yes	-

ChannelReader

WebSocket-backed reader for streaming binary data and text messages.

Name	Type	Required	Description
`close`	async fn() -> Result<(), `Error`>	Yes	-
`new`	fn(engine_ws_base: &str, channel_ref: &`StreamChannelRef`) -> Self	Yes	-
`next_binary`	async fn() -> Result<Option<Vec<u8>>, `Error`>	Yes	Read the next binary chunk from the channel. Text messages are dispatched to registered callbacks. Returns `None` when the stream is closed.
`on_message`	`async fn(callback: F)`	Yes	Register a callback for text messages received on this channel.
`read_all`	async fn() -> Result<Vec<u8>, `Error`>	Yes	Read the entire stream into a single `Vec<u8>`.

ChannelWriter

WebSocket-backed writer for streaming binary data and text messages.

Name	Type	Required	Description
`close`	async fn() -> Result<(), `Error`>	Yes	-
`new`	fn(engine_ws_base: &str, channel_ref: &`StreamChannelRef`) -> Self	Yes	-
`send_message`	async fn(msg: &str) -> Result<(), `Error`>	Yes	-
`write`	async fn(data: &[u8]) -> Result<(), `Error`>	Yes	-

StreamChannelRef

Name	Type	Required	Description
`channel_id`	`String`	Yes	-
`access_key`	`String`	Yes	-
`direction`	`ChannelDirection`	Yes	-

iii_sdk::channels

ChannelDirection · ChannelItem

ChannelDirection

Name	Type	Required	Description
`Read`	`unit`	Yes	-
`Write`	`unit`	Yes	-

ChannelItem

Name	Type	Required	Description
`Text`	`(String)`	Yes	-
`Binary`	`(Vec<u8>)`	Yes	-

iii_sdk::engine

EngineFunctions · EngineTriggers

EngineFunctions

Engine function ids for internal operations.

EngineTriggers

Engine trigger ids.

iii_sdk::errors

Error · InvocationError

Error

Errors returned by the III SDK.

Name	Type	Required	Description
`NotConnected`	`unit`	Yes	-
`Timeout`	`unit`	Yes	-
`Runtime`	`(String)`	Yes	-
`Remote`	`{ code: String, message: String, stacktrace: Option<String> }`	Yes	-
`Handler`	`(String)`	Yes	-
`Serde`	`(String)`	Yes	-
`WebSocket`	`(String)`	Yes	-
`invocation_error`	fn() -> Option<`InvocationError`>	Yes	If this is a remote invocation failure (`Error::Remote`), return its structured form. Returns `None` for transport/serde/handler errors.

InvocationError

Structured invocation failure, mirroring the Node and Python InvocationError. Produced from the Error::Remote variant via Error::invocation_error. function_id is None from that accessor because the wire Remote payload does not carry it.

Name	Type	Required	Description
`code`	`String`	Yes	-
`message`	`String`	Yes	-
`function_id`	`Option<String>`	No	-
`stacktrace`	`Option<String>`	No	-

iii_sdk::protocol

ErrorBody · FunctionMessage · Message · RegisterFunctionMessage · RegisterTriggerInput · RegisterTriggerMessage · RegisterTriggerTypeMessage · TriggerAction · TriggerRequest · TriggerRequestWithMetadata · UnregisterTriggerMessage · UnregisterTriggerTypeMessage

ErrorBody

Name	Type	Required	Description
`code`	`String`	Yes	-
`message`	`String`	Yes	-
`stacktrace`	`Option<String>`	No	-

FunctionMessage

Name	Type	Required	Description
`function_id`	`String`	Yes	-
`description`	`Option<String>`	No	-
`request_format`	`Option<Value>`	No	-
`response_format`	`Option<Value>`	No	-
`metadata`	`Option<Value>`	No	-

Message

Name	Type	Required	Description
`RegisterTriggerType`	`{ id: String, description: String, trigger_request_format: Option<Value>, call_request_format: Option<Value> }`	Yes	-
`RegisterTrigger`	`{ id: String, trigger_type: String, function_id: String, config: Value, metadata: Option<Value> }`	Yes	-
`TriggerRegistrationResult`	{ id: String, trigger_type: String, function_id: String, error: Option<`ErrorBody`> }	Yes	-
`UnregisterTrigger`	`{ id: String, trigger_type: String }`	Yes	-
`UnregisterTriggerType`	`{ id: String }`	Yes	-
`RegisterFunction`	`{ id: String, description: Option<String>, request_format: Option<Value>, response_format: Option<Value>, metadata: Option<Value>, invocation: Option<iii_helpers::http::HttpInvocationConfig> }`	Yes	-
`UnregisterFunction`	`{ id: String }`	Yes	-
`InvokeFunction`	{ invocation_id: Option<uuid::Uuid>, function_id: String, data: Value, traceparent: Option<String>, baggage: Option<String>, action: Option<`TriggerAction`>, metadata: Option<Value> }	Yes	-
`InvocationResult`	{ invocation_id: uuid::Uuid, function_id: String, result: Option<Value>, error: Option<`ErrorBody`>, traceparent: Option<String>, baggage: Option<String> }	Yes	-
`Ping`	`unit`	Yes	-
`Pong`	`unit`	Yes	-
`WorkerRegistered`	`{ worker_id: String }`	Yes	-

RegisterFunctionMessage

Name	Type	Required	Description
`id`	`String`	Yes	-
`description`	`Option<String>`	No	-
`request_format`	`Option<Value>`	No	-
`response_format`	`Option<Value>`	No	-
`metadata`	`Option<Value>`	No	-
`invocation`	`Option<iii_helpers::http::HttpInvocationConfig>`	No	-
`to_message`	fn() -> `Message`	Yes	-

RegisterTriggerInput

Input for IIIClient::register_trigger. The id is auto-generated internally.

Name	Type	Required	Description
`trigger_type`	`String`	Yes	Identifier of the registered trigger type this trigger uses (e.g. `storage::object-created`, `http`).
`function_id`	`String`	Yes	ID of the function this trigger invokes when it fires.
`config`	`Value`	Yes	Trigger-type-specific configuration, matching the shape the trigger type expects.
`metadata`	`Option<Value>`	No	Arbitrary user-specifiable metadata supplied to the triggered handler function on every invocation.

RegisterTriggerMessage

Name	Type	Required	Description
`id`	`String`	Yes	-
`trigger_type`	`String`	Yes	-
`function_id`	`String`	Yes	-
`config`	`Value`	Yes	-
`metadata`	`Option<Value>`	No	-
`to_message`	fn() -> `Message`	Yes	-

RegisterTriggerTypeMessage

Name	Type	Required	Description
`id`	`String`	Yes	Unique identifier for the trigger type (e.g. `state`, `durable:subscriber`).
`description`	`String`	Yes	Human-readable description of what this trigger type does.
`trigger_request_format`	`Option<Value>`	No	-
`call_request_format`	`Option<Value>`	No	-
`to_message`	fn() -> `Message`	Yes	-

TriggerAction

Routing action for TriggerRequest. Determines how the engine handles the invocation.

Enqueue: Routes through a named queue for async processing.
Void: Fire-and-forget, no response.

Name	Type	Required	Description
`Enqueue`	`{ queue: String }`	Yes	Routes the invocation through a named queue.
`Void`	`unit`	Yes	Fire-and-forget routing.

TriggerRequest

Request object for trigger().

// Simple call
TriggerRequest {
    function_id: "my::function".to_string(),
    payload: json!({ "key": "value" }),
    action: None,
    timeout_ms: None,
};

// With action
TriggerRequest {
    function_id: "my::function".to_string(),
    payload: json!({}),
    action: Some(TriggerAction::Enqueue { queue: "payments".to_string() }),
    timeout_ms: None,
};

// With metadata
TriggerRequest {
    function_id: "my::function".to_string(),
    payload: json!({}),
    action: None,
    timeout_ms: None,
}
.metadata(json!({ "tenant": "acme" }));

Name	Type	Required	Description
`function_id`	`String`	Yes	ID of the function to invoke.
`payload`	`Value`	Yes	Input data passed to the function.
`action`	Option<`TriggerAction`>	No	Sets how the trigger is routed. `None` for a synchronous request/response. Set a routing scheme otherwise (e.g. `TriggerAction::Enqueue { .. }`, `TriggerAction::Void`).
`timeout_ms`	`Option<u64>`	No	Override the default invocation timeout, in milliseconds.
`metadata`	fn(metadata: Value) -> `TriggerRequestWithMetadata`	Yes	Attach per-invocation metadata without adding a required field to `TriggerRequest` struct literals.

TriggerRequestWithMetadata

Trigger request plus optional per-invocation metadata.

UnregisterTriggerMessage

Name	Type	Required	Description
`id`	`String`	Yes	-
`trigger_type`	`String`	Yes	-
`to_message`	fn() -> `Message`	Yes	-

UnregisterTriggerTypeMessage

Name	Type	Required	Description
`id`	`String`	Yes	-
`to_message`	fn() -> `Message`	Yes	-

iii_sdk::runtime

FunctionInfo · FunctionRef · IIIConnectionState · TriggerInfo · TriggerTypeRef · WorkerInfo · WorkerMetadata

FunctionInfo

Function information returned by engine::functions::list

Name	Type	Required	Description
`function_id`	`String`	Yes	-
`description`	`Option<String>`	No	-
`request_format`	`Option<Value>`	No	-
`response_format`	`Option<Value>`	No	-
`metadata`	`Option<Value>`	No	-

FunctionRef

Name	Type	Required	Description
`id`	`String`	Yes	-
`unregister`	`fn()`	Yes	-

IIIConnectionState

Connection state for the III WebSocket client

Name	Type	Required	Description
`Disconnected`	`unit`	Yes	-
`Connecting`	`unit`	Yes	-
`Connected`	`unit`	Yes	-
`Reconnecting`	`unit`	Yes	-
`Failed`	`unit`	Yes	-

TriggerInfo

Trigger information returned by engine::triggers::list

Name	Type	Required	Description
`id`	`String`	Yes	-
`trigger_type`	`String`	Yes	-
`function_id`	`String`	Yes	-
`config`	`Value`	Yes	-
`metadata`	`Option<Value>`	No	-

TriggerTypeRef

Typed handle returned by IIIClient::register_trigger_type. Type parameters:

C: trigger registration type for register_trigger
R: call request type for register_function

Name	Type	Required	Description
`register_function`	fn(id: impl Into<String>, f: F) -> `FunctionRef`	Yes	Register a sync function whose input type must match the call request format `R`.
`register_function_async`	fn(id: impl Into<String>, f: F) -> `FunctionRef`	Yes	Register an async function whose input type must match the call request format `R`.
`register_trigger`	fn(function_id: impl Into<String>, config: C) -> Result<`Trigger`, `Error`>	Yes	Register a trigger with compile-time validated trigger config.
`register_trigger_with_metadata`	fn(function_id: impl Into<String>, config: C, metadata: Option<Value>) -> Result<`Trigger`, `Error`>	Yes	Register a trigger with compile-time validated trigger config and optional metadata.

WorkerInfo

Worker information returned by engine::workers::list

Name	Type	Required	Description
`id`	`String`	Yes	-
`name`	`Option<String>`	No	-
`runtime`	`Option<String>`	No	-
`version`	`Option<String>`	No	-
`os`	`Option<String>`	No	-
`ip_address`	`Option<String>`	No	-
`status`	`String`	Yes	-
`connected_at_ms`	`u64`	Yes	-
`function_count`	`usize`	Yes	-
`functions`	`Vec<String>`	Yes	-
`active_invocations`	`usize`	Yes	-
`isolation`	`Option<String>`	No	-

WorkerMetadata

Worker metadata for auto-registration

Name	Type	Required	Description
`runtime`	`String`	Yes	-
`version`	`String`	Yes	-
`name`	`String`	Yes	-
`os`	`String`	Yes	-
`description`	`Option<String>`	No	One-line, human/LLM-readable summary of what this worker does. Surfaces in `engine::workers::list` / `engine::workers::info`.
`pid`	`Option<u32>`	No	-
`telemetry`	Option<`TelemetryOptions`>	No	-
`isolation`	`Option<String>`	No	-

iii_sdk::stream_provider

IStream

IStream

Custom stream-provider trait. Implementors override the engine’s built-in stream storage for a specific stream name when registered through create_stream in the helpers submodule.

Name	Type	Required	Description
`get`	`fn(input: StreamGetInput) -> Pin<Box<dyn Future + Send>>`	Yes	-
`set`	`fn(input: StreamSetInput) -> Pin<Box<dyn Future + Send>>`	Yes	-
`delete`	`fn(input: StreamDeleteInput) -> Pin<Box<dyn Future + Send>>`	Yes	-
`list`	`fn(input: StreamListInput) -> Pin<Box<dyn Future + Send>>`	Yes	-
`list_groups`	`fn(input: StreamListGroupsInput) -> Pin<Box<dyn Future + Send>>`	Yes	-
`update`	`fn(input: StreamUpdateInput) -> Pin<Box<dyn Future + Send>>`	Yes	-

iii_sdk::structs

MiddlewareFunctionInput

MiddlewareFunctionInput

Input passed to the RBAC middleware function on every function invocation through the RBAC port. The middleware can inspect, modify, or reject the call before it reaches the target function.

Name	Type	Required	Description
`function_id`	`String`	Yes	ID of the function being invoked.
`payload`	`Value`	Yes	Payload sent by the caller.
`action`	Option<`TriggerAction`>	No	Routing action, if any.
`context`	`Value`	Yes	Auth context returned by the auth function for this session.

iii_sdk::trigger

IIITrigger · Trigger · TriggerConfig · TriggerHandler

IIITrigger

Enum of all built-in trigger types with typed configuration. Use .for_function() to create a RegisterTriggerInput:

let input = IIITrigger::Cron(CronTriggerConfig::new("0 * * * * *"))
    .for_function("my::handler");

Name	Type	Required	Description
`Http`	(`HttpTriggerConfig`)	Yes	-
`Cron`	(`CronTriggerConfig`)	Yes	-
`Queue`	(`QueueTriggerConfig`)	Yes	-
`Subscribe`	(`SubscribeTriggerConfig`)	Yes	-
`State`	(`StateTriggerConfig`)	Yes	-
`Stream`	`(iii_helpers::stream::StreamTriggerConfig)`	Yes	-
`StreamJoin`	`(iii_helpers::stream::StreamJoinLeaveTriggerConfig)`	Yes	-
`StreamLeave`	`(iii_helpers::stream::StreamJoinLeaveTriggerConfig)`	Yes	-
`Log`	(`LogTriggerConfig`)	Yes	-
`for_function`	fn(function_id: impl Into<String>) -> `RegisterTriggerInput`	Yes	Create a `RegisterTriggerInput` binding this trigger to a function.

Trigger

Handle returned by IIIClient::register_trigger. Call unregister to remove the trigger from the engine.

Name	Type	Required	Description
`new`	`fn(unregister_fn: Arc<dyn Fn() + Send + Sync>) -> Self`	Yes	-
`unregister`	`fn()`	Yes	Remove this trigger from the engine.

TriggerConfig

Configuration passed to a TriggerHandler when a trigger instance is registered or unregistered.

Name	Type	Required	Description
`id`	`String`	Yes	Trigger instance ID.
`function_id`	`String`	Yes	Function to invoke when the trigger fires.
`config`	`Value`	Yes	Trigger-specific configuration.
`metadata`	`Option<Value>`	No	Arbitrary user-specifiable metadata supplied to the triggered handler function on every invocation.

TriggerHandler

Handler trait for custom trigger types. Implement this and pass to IIIClient::register_trigger_type.

Name	Type	Required	Description
`register_trigger`	fn(config: `TriggerConfig`) -> Pin<Box<dyn Future + Send>>	Yes	Called when a trigger instance is registered.
`unregister_trigger`	fn(config: `TriggerConfig`) -> Pin<Box<dyn Future + Send>>	Yes	Called when a trigger instance is unregistered.

iii_sdk::types

RemoteFunctionData · RemoteFunctionHandler · RemoteTriggerTypeData · StreamRequest · StreamResponse

RemoteFunctionData

Name	Type	Required	Description
`message`	`RegisterFunctionMessage`	Yes	-
`handler`	`Option<RemoteFunctionHandlerWithMetadata>`	No	-

RemoteFunctionHandler

A dispatchable function handler. Receives the invocation payload. Handlers that also want the optional per-invocation metadata sidecar use RemoteFunctionHandlerWithMetadata; this single-argument shape is kept for backward compatibility.

type RemoteFunctionHandler = Arc<dyn Fn(Value) -> futures_util::future::BoxFuture<'static, Result<Value, Error>> + Send + Sync>

RemoteTriggerTypeData

Name	Type	Required	Description
`message`	`RegisterTriggerTypeMessage`	Yes	-
`handler`	Arc<dyn `TriggerHandler`>	Yes	-

StreamRequest

Incoming streaming request received by a function registered with a stream trigger. Alias of iii_helpers::http::HttpRequest.

type StreamRequest = iii_helpers::http::HttpRequest<T>

StreamResponse

Streaming response type, mirroring the Node and Python StreamResponse. Alias of iii_helpers::http::HttpResponse; added for cross-language parity.

type StreamResponse = iii_helpers::http::HttpResponse<T>

​Installation

​Initialization

​register_worker

​Methods

​register_trigger

​register_function

​trigger

​register_trigger_type

​unregister_trigger_type

​get_connection_state

​Example

​shutdown

​Example

​shutdown_async

​Example

​Types

​iii_sdk

​EnqueueResult

​InitOptions

​RegisterFunction

​RegisterTriggerType

​TelemetryOptions

​iii_sdk::builtin_triggers

​CronCallRequest

​CronTriggerConfig

​HttpCallRequest

​HttpMethod

​HttpTriggerConfig

​LogCallRequest

​LogLevel

​LogTriggerConfig

​QueueTriggerConfig

​StateCallRequest

​StateEventType

​StateTriggerConfig

​SubscribeTriggerConfig

​iii_sdk::channel

​Channel

​ChannelReader

​ChannelWriter

​StreamChannelRef

​iii_sdk::channels

​ChannelDirection

​ChannelItem

​iii_sdk::engine

​EngineFunctions

​EngineTriggers

​iii_sdk::errors

​Error

​InvocationError

​iii_sdk::protocol

​ErrorBody

​FunctionMessage

​Message

​RegisterFunctionMessage

​RegisterTriggerInput

​RegisterTriggerMessage

​RegisterTriggerTypeMessage

​TriggerAction

​TriggerRequest

​TriggerRequestWithMetadata

​UnregisterTriggerMessage

​UnregisterTriggerTypeMessage

​iii_sdk::runtime

​FunctionInfo

​FunctionRef

​IIIConnectionState

​TriggerInfo

​TriggerTypeRef

​WorkerInfo

​WorkerMetadata

​iii_sdk::stream_provider

​IStream

​iii_sdk::structs

​MiddlewareFunctionInput

​iii_sdk::trigger

​IIITrigger

​Trigger

​TriggerConfig

​TriggerHandler

Installation

Initialization

register_worker

Methods

register_trigger

register_function

trigger

register_trigger_type

unregister_trigger_type

get_connection_state

Example

shutdown

Example

shutdown_async

Example

Types

iii_sdk

EnqueueResult

InitOptions

RegisterFunction

RegisterTriggerType

TelemetryOptions

iii_sdk::builtin_triggers

CronCallRequest

CronTriggerConfig

HttpCallRequest

HttpMethod

HttpTriggerConfig

LogCallRequest

LogLevel

LogTriggerConfig

QueueTriggerConfig

StateCallRequest

StateEventType

StateTriggerConfig

SubscribeTriggerConfig

iii_sdk::channel

Channel

ChannelReader

ChannelWriter

StreamChannelRef

iii_sdk::channels

ChannelDirection

ChannelItem

iii_sdk::engine

EngineFunctions

EngineTriggers

iii_sdk::errors

Error

InvocationError

iii_sdk::protocol

ErrorBody

FunctionMessage

Message

RegisterFunctionMessage

RegisterTriggerInput

RegisterTriggerMessage

RegisterTriggerTypeMessage

TriggerAction

TriggerRequest

TriggerRequestWithMetadata

UnregisterTriggerMessage

UnregisterTriggerTypeMessage

iii_sdk::runtime

FunctionInfo

FunctionRef

IIIConnectionState

TriggerInfo

TriggerTypeRef

WorkerInfo

WorkerMetadata

iii_sdk::stream_provider

IStream

iii_sdk::structs

MiddlewareFunctionInput

iii_sdk::trigger

IIITrigger

Trigger

TriggerConfig

TriggerHandler