LangStage

Every stage for your LangGraph agent.

Write your agent once — any LangGraph CompiledGraph, from a single ReAct agent to a multi-agent supervisor — and run it on every surface with the same spec string, the same langstage.toml config, and the same LANGSTAGE_* environment variables. The web, your terminal, JupyterLab, and VS Code all become stages your agent can perform on.

Your agent on the web stage — streaming, tool calls, a file browser, and a canvas.

Multi-agent? It already works.

A supervisor, swarm, or crew compiles to the same CompiledStateGraph LangStage loads — so multi-agent routing and hand-offs run and stream exactly like a single agent, with no extra setup. See Running a multi-agent supervisor.

30-second quickstart

No agent or API key yet? See a stage working with the built-in keyless demo agent:

pip install langstage
langstage run --demo

Then point it at your agent — a Python file (or module) that exports a LangGraph CompiledGraph:

langstage run --agent my_agent.py:graph

That same my_agent.py:graph spec runs unchanged on every other stage below.

The family

Stage	Package	Try it
Web app	langstage	langstage run --agent my_agent.py:graph
Terminal	langstage-cli	langstage-cli -a my_agent.py:graph
JupyterLab	langstage-jupyter	pip install langstage-jupyter, then the chat sidebar
VS Code	langstage-vscode	the @langstage chat participant
Reference agent	langstage-hermes	LANGSTAGE_AGENT_SPEC=langstage_hermes.agent:graph
Shared core	langgraph-stream-parser	typed events + config resolver behind every stage

Why LangStage

• Write once, run anywhere. A single module:attr / path/to/file.py:attr spec string is understood identically by every stage.
• Keyless demo on every stage. Each surface ships a --demo mode backed by a deterministic echo agent, so you can see it work before configuring keys.
• One config story. defaults < langstage.toml < LANGSTAGE_* env < flags — inspect the resolved values anywhere with --show-config.
• Built on the standard. Pure LangGraph / deepagents; the shared core is just a typed parser for graph.stream() output.

Coming from deepagent-* or cowork-dash?

Every package was renamed into the LangStage family. Your old pip installs, imports, and commands still work — see Migrating.

Start with Installation →