Overview

Write durable agents in TypeScript: @duraton/sdk authors workflows, runs a runner, and calls Duraton from app code, all from one package.

@duraton/sdk is how you author workflows, run them on a runner, and talk to Duraton from app code. Install it and import from the package root:

npm install @duraton/sdk

pnpm add @duraton/sdk

yarn add @duraton/sdk

bun add @duraton/sdk

import {
  defineWorkflow,
  connect,
  serve,
  register,
  createClient,
  NonRetriableError,
  RetryAfterError,
  PollTimeoutError,
} from "@duraton/sdk";

Entry points

Every export is reachable from the package root. The scoped entries are subsets, for code that should not pull in the rest.

import { createClient } from "@duraton/sdk/client";   // no workflow authoring, no runner
import { createMemoryCache } from "@duraton/sdk/ai";  // the AI ports and their adapters
import { serve } from "@duraton/sdk/hono";            // one framework adapter

Entry	Contains	Use it when
`@duraton/sdk`	Everything below, plus `defineWorkflow`, `connect`, `serve`, `register`, `hashStepId`, and the error types.	Authoring workflows and running a runner.
`@duraton/sdk/client`	`createClient`, `DuratonApiError`, and the REST DTOs.	App code that only calls Duraton - an admin tool, a frontend, a script.
`@duraton/sdk/ai`	The `AIProvider` and `AICache` ports, their adapters, and the AI journal types.	Supplying your own model provider or cache store.
`@duraton/sdk/bun` `/hono` `/elysia` `/express` `/fastify` `/next` `/node`	One `serve` adapter each.	Mounting an HTTP runner on that framework.

The surface

Defining workflows

defineWorkflow: name, triggers, retry, flow control.

Steps

The handler context and the durable step API.

connect

Run a runner over an outbound WebSocket - no inbound URL.

Serving runners

serve, register, the framework adapters, and the error types.

REST client

createClient: trigger events, read and control runs.

AI steps

step.ai: durable model calls, agent loops, providers, cache.

Evals

ctx.score, ctx.assert, deferred scorers, datasets.

Python SDK

uv add duraton: the async runner, steps, step.ai, and the REST client.

Go SDK

go get duraton.dev/sdk-go: the runner, generic steps, step.ai, and the REST client.

Prefer another language? The Python and Go SDKs speak the same connect protocol and cover the same surface - workflows, durable steps, step.ai, and a REST client.