Rust SDK

The native async Rust SDK for connecting workers to the iii engine via tokio.

Documentation

Full API reference: https://iii.dev/docs/api-reference/sdk-rust

Install

Add to Cargo.toml:

iii-sdk = { version = "0.10", features = ["otel"] }

Key Types and Functions

Export	Purpose
register_worker(url, InitOptions)	Connect to the engine, returns III client
III::register_function(RegisterFunction::new(id, handler))	Register a sync function using the builder API
III::register_function(RegisterFunction::new_async(id, handler))	Register an async function using the builder API
III::register_function_with(msg, handler)	Two-arg convenience method for function registration
RegisterFunction	Builder with .description() and auto-generated request schemas via schemars
III::register_trigger(type, function_id, config)	Bind a trigger to a function
III::trigger(TriggerRequest)	Invoke a function
TriggerAction::Void	Fire-and-forget invocation
TriggerAction::Enqueue { queue }	Durable async invocation
IIIError	Error type for handler failures
Streams	Helper for atomic stream CRUD
with_span, get_tracer, get_meter	OpenTelemetry (requires otel feature)
execute_traced_request	HTTP client with trace context propagation

Key Notes

• Add features = ["otel"] to Cargo.toml for OpenTelemetry support
• Use RegisterFunction::new("id", handler) for sync handlers, RegisterFunction::new_async("id", handler) for async
• Handler input types that derive schemars::JsonSchema get auto-generated request schemas
• Chain .description("...") on RegisterFunction to document the function
• Keep the tokio runtime alive (e.g., tokio::time::sleep loop) for event processing
• register_trigger returns Ok(()) on success; propagate errors with ?

Pattern Boundaries

• For usage patterns and working examples, see iii-functions-and-triggers
• For Node.js SDK, see iii-node-sdk
• For Python SDK, see iii-python-sdk

When to Use

• Use this skill when the task is primarily about iii-rust-sdk in the iii engine.
• Triggers when the request directly asks for this pattern or an equivalent implementation.

Boundaries

• Never use this skill as a generic fallback for unrelated tasks.
• You must not apply this skill when a more specific iii skill is a better fit.
• Always verify environment and safety constraints before applying examples from this skill.