> ## Documentation Index
> Fetch the complete documentation index at: https://usefused.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Serve a project

> Launch the neutral server and development playground.

From the agent folder, compile and start the standalone development server:

```bash theme={null}
harnest serve .
```

Send a message from another terminal:

```bash theme={null}
curl --fail-with-body -sS http://127.0.0.1:1907/responses \
  -H 'Content-Type: application/json' \
  -d '{"input":"Hello! What can you help me with?"}'
```

The response includes `outputText` and a `sessionId` you can reuse. See [API requests and streaming examples](/docs/harnest/runtime/serving/neutral-api) for the request fields, typed inputs, authentication, and SSE. Startup output lists the Swagger URL and downloadable `openapi.json` / `openapi.yaml` resources. Calling agents can discover those resources through `/agent`. Set [`server.openapi: false`](/docs/harnest/runtime/serving/server-configuration#hide-api-documentation) to hide them.

For a normal launch without `--output` or `--reload`, Harnest retains the
validated compilation under `.harnest/artifacts/`. A later launch with the same
source, configuration, locks, and managed compiler starts from that artifact
without importing and validating the graph again. When any of those inputs
changes, Harnest publishes a new immutable generation before it removes the
superseded generation in the background.

Reload after authored file changes during local development:

```bash theme={null}
harnest serve . --reload
```

| URL                             | Use it for                       |
| ------------------------------- | -------------------------------- |
| `http://127.0.0.1:1907/`        | Test the agent in the playground |
| `http://127.0.0.1:1907/docs`    | Inspect the generated API        |
| `http://127.0.0.1:1907/healthz` | Check process health             |

<CardGroup cols={2}>
  <Card title="Open the playground" icon="display" href="http://127.0.0.1:1907/">
    Test managed or advanced ADK and LangGraph agents in the same UI.
  </Card>

  <Card title="Inspect the API" icon="brackets-curly" href="http://127.0.0.1:1907/docs">
    Explore HTTP, SSE, sessions, approvals, and client tools.
  </Card>
</CardGroup>

<Note>
  Override the bind, limits, timeout, concurrency, or playground under the optional `server:` section in `config.yaml`. Omit it to use the defaults.
</Note>

See [development reload](/docs/harnest/runtime/serving/development-reload) for restart behavior and [Serving agents](/docs/harnest/runtime/serving) for the HTTP, SSE, WebSocket, approval, authentication, storage, and production boundaries.