deepagents/examples/async-subagent-server

Async Subagent Server

A self-hosted Agent Protocol server that exposes a Deep Agents researcher as an async subagent. Use this as a starting point for hosting your own agent on any infrastructure and connecting it to a Deep Agents supervisor.

The example includes both sides of the pattern:

• server.py — the FastAPI server your subagent runs on
• supervisor.py — an interactive REPL showing how to connect to it

Prerequisites

• ANTHROPIC_API_KEY — required
• TAVILY_API_KEY — optional; stub search is used if not set

Quickstart

1. Install dependencies:

cd examples/async-subagent-server
uv sync

2. Set up your environment:

cp .env.example .env
# fill in ANTHROPIC_API_KEY (and optionally TAVILY_API_KEY)

3. Start the server:

uv run uvicorn server:app --port 2024

4. In another terminal, start the supervisor:

cd examples/async-subagent-server
ANTHROPIC_API_KEY=... uv run python supervisor.py

Try these prompts:

> research the latest developments in quantum computing
> check status of <task-id>
> update <task-id> to focus on commercial applications only
> cancel <task-id>
> list all tasks

Implemented endpoints

These are the Agent Protocol endpoints the Deep Agents async subagent middleware calls (via the LangGraph SDK):

Endpoint	Purpose
POST /threads	Create a thread for a new task
POST /threads/{thread_id}/runs	Start or interrupt+restart a run
GET /threads/{thread_id}/runs/{run_id}	Poll run status
GET /threads/{thread_id}	Fetch thread state (values.messages)
POST /threads/{thread_id}/runs/{run_id}/cancel	Cancel a run
GET /ok	Health check

Swap in your own agent

Replace the create_deep_agent call in server.py with your own agent. The Agent Protocol layer stays the same regardless of what the agent does.

_agent = create_deep_agent(
    model=ChatAnthropic(model="claude-sonnet-4-5"),
    system_prompt="You are a ...",
    tools=[your_tool],
)

⚠️ For demonstration purposes only

This example is intended to illustrate the self-hosted async subagent pattern. It does not feature authentication, rate limiting, or other features required for production use.

Resources

• LangChain Academy — Comprehensive, free courses on LangChain libraries and products, made by the LangChain team.
• Code of Conduct — community guidelines and standards