Functions & Triggers

Comparable to: Serverless function runtimes, Lambda, Cloud Functions

Key Concepts

Use the concepts below when they fit the task. Not every worker needs all of them.

• A Function is an async handler registered with a unique ID
• A Trigger binds an event source to a function — types include http, durable:subscriber, cron, state, stream, and subscribe
• Functions invoke other functions via trigger() regardless of language or worker location
• The engine handles serialization, routing, and delivery automatically
• HTTP-invoked functions wrap external endpoints as callable function IDs
• Functions can declare request/response formats for documentation and discovery — auto-generated from types in Rust (via schemars::JsonSchema) and Python (via type hints / Pydantic), or manually provided in Node.js

Architecture

registerWorker() connects the worker to the engine, registerFunction defines handlers, registerTrigger binds event sources to those handlers, and the engine routes incoming events to the correct function. Functions can invoke other functions across workers and languages via trigger().