Show HN: Durable Actors – OSS Durable Objects with configurable compute

TerseAI released Durable Actors, an open-source alternative to Cloudflare Durable Objects that provides stateful serverless functions with durable state and serialized execution, self-hostable on GCP with no vendor lock-in. The runtime supports Python and TypeScript clients, requires Node.js 22.19+ and Bun 1.3.9+, and is aimed at real-time applications such as chat systems, collaboration tools, and agent swarms.

an open-source alternative to Cloudflare Durable Objects... with no vendor lock-in, memory limits, and observability built in. Durable Actors help you build real-time applications like chat systems e.g. ChatGPT, Codex , collaboration tools e.g. Notion , and agent swarms e.g. Devin . They provide stateful serverless functions , a foundational building block that abstracts away persistence, coordination, and infrastructure challenges in distributed systems. Live demo https://demo.useterse.ai · TypeScript documentation https://github.com/TerseAI/durable-actors/blob/main/docs/reference/typescript-guide.md · Python documentation https://github.com/TerseAI/durable-actors/blob/main/docs/reference/python-guide.md 1. Define an actor , a class with durable state i.e. data survives interruptions, errors, and restarts and serialized execution i.e. concurrent callers can update it safely . For example: - If you were building ChatGPT... a chat actor can store conversations that survive LLM flakiness and server crashes durable state - If you were building Notion... a document actor can coordinate concurrent edits from several people and agents serialized execution 1. Generate type-safe clients automatically with the Durable Actors SDK. For now, it supports Python and TypeScript. 2. Develop locally with one command and later self-host the Durable Actors runtime on GCP https://github.com/TerseAI/durable-actors/blob/main/docs/self-hosting.md . Install Node.js 22.19+ and Bun 1.3.9+. npx durable-actors init my-actors cd my-actors npm install npx durable-actors dev Run the server locally on your machine Define and export actors in your actor project’s src/actors.ts , the default entrypoint loaded by durable-actors dev . The runtime loads actors on demand and persists fields marked @Persisted . For example, a chat history actor: js import { openai } from "@ai-sdk/openai" import { streamText } from "ai" import { Actor, type ActorSocket, Interleave, Persisted } from "durable-actors" type Message = { role: "user" | "assistant"; content: string } export class ChatHistory extends Actor<null, string, Message { @Persisted messages: Message = async onConnect socket: ActorSocket<null, Message { socket.send this.messages } @Interleave // Let other calls run during await, e.g. new connections while a reply streams. async onMessage socket: ActorSocket<null, Message , text: string { this.messages.push { role: "user", content: text } const result = streamText { model: openai "gpt-5-mini" , messages: ...this.messages } const reply: Message = { role: "assistant", content: "" } this.messages.push reply this.broadcast this.messages for await const chunk of result.textStream { reply.content += chunk this.broadcast this.messages } } } We make it super easy to integrate the actors into your existing tech stack. Just generate the client and you get a fully type safe contract to interact with. npx durable-actors generate Create a WebSocket connection to one shared chat: python import express from "express" import { actors } from "../generated/index.js" export const app = express app.post "/api/chat/socket", async req, res = { const grant = await actors.ChatHistory.prepareWebsocket { actorId: "lobby", metadata: null } res.set "Cache-Control", "no-store" .json grant } js import { useEffect, useRef, useState } from "react" import { createRoot } from "react-dom/client" import type { actors } from "../generated/index.js" function Chat { const socket = useRef<WebSocket null const messages, setMessages = useState<actors.ChatHistory.Outgoing useEffect = { let active = true async function connect { const response = await fetch "/api/chat/socket", { method: "POST" } const { websocketUrl } = await response.json if active return socket.current = new WebSocket websocketUrl socket.current.onmessage = event = setMessages JSON.parse event.data } void connect return = { active = false socket.current?.close } }, function send form: FormData { const text = String form.get "message" .trim if text || socket.current?.readyState == WebSocket.OPEN return socket.current.send JSON.stringify text } return <main <div role="log" aria-label="Messages" {messages.map message, index = <p key={index} <strong {message.role}:</strong {message.content}</p } </div <form action={send} <input name="message" aria-label="Message" required / <button Send</button </form </main } createRoot document.getElementById "root" .render <Chat / For a complete app with error handling and retries, see the AI Chat example https://github.com/TerseAI/durable-actors/blob/main/examples/ai-chat . Durable Agents provides built-in observability features: For complete sample applications, see AI Chat https://github.com/TerseAI/durable-actors/blob/main/examples/ai-chat , Collaborative Documents https://github.com/TerseAI/durable-actors/blob/main/examples/documents , and Chatroom https://github.com/TerseAI/durable-actors/blob/main/examples/chat . Bug reports, feature requests, documentation fixes, and code contributions are welcome. See the contributing guide https://github.com/TerseAI/durable-actors/blob/main/CONTRIBUTING.md for repository setup and checks, and follow our code of conduct https://github.com/TerseAI/durable-actors/blob/main/CODE OF CONDUCT.md . Use GitHub Issues https://github.com/TerseAI/durable-actors/issues for bugs, ideas, and questions. Report vulnerabilities privately using our security policy https://github.com/TerseAI/durable-actors/blob/main/SECURITY.md . Follow development and release notes on GitHub Releases https://github.com/TerseAI/durable-actors/releases . MIT https://github.com/TerseAI/durable-actors/blob/main/LICENSE.md © 2026 Terse