---
title: "LangGraph Starter"
---

import SupportCTA from "/snippets/support-cta.mdx";

<SupportCTA />

## Summary

This starter shows the smallest useful graph-shaped agent example in the repo:
plan, route, synthesize.

## Status

`starter`

Source code: [ecosystem/examples/langgraph-starter](https://github.com/Prompthon-IO/agent-systems-handbook/tree/main/ecosystem/examples/langgraph-starter)

## Why It Exists

Framework comparison pages are easier to extend when contributors can point to
small repo-owned examples instead of only to external demos. This starter keeps
the shape recognizable without turning the repo into a framework tutorial set.

## Related Lab Pages

- [Agent Frameworks](/ecosystem/agent-frameworks)
- [Ecosystem Overview](/ecosystem)

## Folder Structure

```text
langgraph-starter/
├── index.mdx
└── src/
    ├── branching.py
    ├── graph.py
    └── run_summary.py
```

## Quick Start

This project is a starter. Read `src/graph.py` for the minimal graph state and
node boundaries, then expand it into a fuller runnable example if needed. For a
repo-level smoke check, run `python3 scripts/verify_example_projects.py` from
the repository root.

## Included Sample Files

- `src/graph.py`: a minimal plan, route, synthesize state transition sketch
- `src/branching.py`: a narrow example of how route choice and retry policy can
  be made explicit
- `src/run_summary.py`: a tiny reporting surface for turning graph state into a
  readable execution summary

## Constraints

- No framework dependency is wired.
- The graph is illustrative rather than executable.
- Tool adapters and model calls are placeholders.

## Next Steps

- Add a real runtime dependency.
- Add one tool node and one retry path.