Simple Agent Template

Minimal deployment template for a LangChain agent built with create_agent(...).

What this template gives you

• A deployable LangGraph entrypoint at src/simple_agent/graph.py.
• Two small tools (utc_now, calculator) for predictable local behavior.
• langgraph.json configured for LangSmith/LangGraph deployment.
• A uv-managed local workflow with a small Makefile wrapper and starter tests.

Additions to this starter kit

• OpenRouter automatically plugged in
• LangChain MCP servers in .vscode/mcp.json (https://docs.langchain.com/use-these-docs)
• Demo of a script mcp server with fastmcp (mcp_agent_demo)

Quickstart

1. Sync the project with uv:

uv sync --dev

2. Configure environment:

cp .env.example .env

3. Run locally:

uv run langgraph dev --studio-url https://eu.smith.langchain.com

Or with tunnel:

uv run langgraph dev --tunnel --studio-url https://eu.smith.langchain.com

Optional make wrappers:

make dev
make run

Upgrade modules

# Update versions from the lock
uv lock --upgrade
# Alternative pOur un package unique:
# uv lock --upgrade-package mon-package
# Install them
uv sync

Tests and lint

make test
make integration-tests
make lint
make format

Integration tests are skipped unless ANTHROPIC_API_KEY is set.

Deploy to LangSmith

1. Push this template to a Git repository.
2. In LangSmith, create a new Deployment from that repo.
3. Set required environment variables (ANTHROPIC_API_KEY, optionally LANGSMITH_API_KEY).
4. Deploy using langgraph.json defaults.

Reference docs

• LangChain quickstart: https://docs.langchain.com/oss/python/langchain/quickstart
• LangChain deployment: https://docs.langchain.com/oss/python/langchain/deploy