FastAgent
FastAgent is a serving runtime that turns a file-defined agent directory (AGENTS.md, skills/, tools/) into a live service. It solves the problem of local agents being stuck in the terminal by providing adapters for Telegram, GitHub, webhooks, API endpoints, and app embedding. It is for developers who have built agents with coding agents and want to deploy them as real services without rewriting them.
✨ Key features
- Point FastAgent at an existing AGENTS.md + skills/ directory; no new DSL.
- Serve the same agent across Telegram, GitHub, Feishu/Lark, HTTP/SSE, or custom channels.
- Supports any model provider (OpenAI, Anthropic, Google) via OAuth or API key.
- Typed tools discovered from tools/ with Zod validation; Agent Skills loaded on demand.
- Embed in Next/Astro/Hono/Bun/Node apps with one handler or invoke as a function.
- Deploy anywhere with no build step: Docker, Fly, Railway, or AWS Bedrock AgentCore.
🎯 Use cases
- Turn a coding-agent-generated agent directory into a Telegram bot.
- Add a GitHub PR review bot to your repository using webhooks.
- Embed an agent into a Next.js or Astro app as an API route.
- Expose an agent as an HTTP/SSE endpoint for custom clients.
- Deploy an agent to Fly, Railway, or AWS Bedrock AgentCore with generated config.
📦 Installation
🧰 Requirements: Requires Node >= 22.19 or Bun 1.3+; model provider API keys or OAuth as needed.
npm i -g @fastagent-sh/fastagent # CLI: fastagent init/dev/start/...
npm i @fastagent-sh/fastagent # library API for embedding or code tools
🚀 Usage
fastagent init my-agent
cd my-agent
fastagent dev
Then send a local test turn:
curl -N -X POST localhost:8787/invoke \
-H 'content-type: application/json' \
-d '{"session":"s1","text":"hello"}'
⚠️ Good to know
FastAgent is pre-1.0; the package API may tighten before 1.0, and durable execution, sandboxing, and observability export are not yet complete.
❓ FAQ
What is the minimum Node version?
Node >= 22.19 is required, inherited from the pi harness and undici; it also runs under Bun 1.3+.
Can I use my own agent harness?
Yes, the Agent Handler contract is harness-neutral; you can bring your own harness and all channels keep working.
Does FastAgent require a specific model provider?
No, it supports any provider (OpenAI, Anthropic, Google, etc.) via OAuth or API key.
Is there a build step for deployment?
No, the directory is the deployable unit; you can deploy directly to Docker, Fly, Railway, or AWS Bedrock AgentCore.
📊 Repository
🤖 Overview, features, install steps and FAQ were generated from the project's README on Sep 4, 2026. Always check the original source before running commands.