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

# Envoy CLI

> Auto-generate an MCP server from your backend codebase

Envoy reads your backend code, generates a complete MCP server, and deploys it to Crow — so your agent can call your API without you writing any MCP code.

<Info>
  **No MCP knowledge required.** Envoy analyzes your routes, schemas, and auth patterns, then builds and deploys a production-ready MCP server for you.
</Info>

## Quick Start

```bash theme={null}
export CROW_API_KEY=ck_...
npx @usecrow/envoy
```

Run this from the root directory that contains your project folders (backend, frontend, etc.). Envoy will ask which directories are relevant before it starts.

### Get Your API Key

1. Go to [app.usecrow.com](https://app.usecrow.com) → **Tools**
2. Click **Generate Envoy Key**
3. Copy the `ck_...` key

## Commands

<CodeGroup>
  ```bash Generate (default) theme={null}
  npx @usecrow/envoy
  ```

  ```bash Fix / Iterate theme={null}
  npx @usecrow/envoy fix
  ```

  ```bash Deploy theme={null}
  npx @usecrow/envoy deploy
  ```
</CodeGroup>

| Command    | What it does                                                            |
| ---------- | ----------------------------------------------------------------------- |
| `generate` | Reads your codebase, generates an MCP server from scratch               |
| `fix`      | Loads your existing MCP server and iterates on it (add tools, fix bugs) |
| `deploy`   | Deploys the latest saved version to production                          |

## Options

| Flag              | Description                                                             |
| ----------------- | ----------------------------------------------------------------------- |
| `--api-key <key>` | Crow API key (alternative to `CROW_API_KEY` env var)                    |
| `--ci`            | CI mode — structured JSON output on stdout                              |
| `--dirs <a,b,c>`  | Comma-separated directories to scan (CI mode, skips interactive prompt) |
| `--help, -h`      | Show help                                                               |
| `--version, -v`   | Show version                                                            |

## How It Works

```
1. npx @usecrow/envoy
2. Envoy scans your project directories
3. AI agent analyzes routes, schemas, auth patterns
4. Generates a complete MCP server (server.py + requirements.txt)
5. Saves to Crow with versioning
6. Deploy when ready → your agent can now call your API
```

### What Envoy Generates

Envoy produces a [FastMCP](https://github.com/jlowin/fastmcp) server that wraps your API endpoints as MCP tools. For example, if your backend has:

```python theme={null}
@app.get("/api/orders/{order_id}")
async def get_order(order_id: str):
    ...

@app.post("/api/orders/{order_id}/cancel")
async def cancel_order(order_id: str):
    ...
```

Envoy generates:

```python theme={null}
from fastmcp import FastMCP

mcp = FastMCP("My Backend")

@mcp.tool()
async def get_order(order_id: str) -> dict:
    """Look up an order by ID. Returns order details including status and total."""
    async with httpx.AsyncClient() as client:
        response = await client.get(f"{API_BASE_URL}/api/orders/{order_id}", ...)
        return response.json()

@mcp.tool()
async def cancel_order(order_id: str) -> dict:
    """Cancel a pending order."""
    async with httpx.AsyncClient() as client:
        response = await client.post(f"{API_BASE_URL}/api/orders/{order_id}/cancel", ...)
        return response.json()
```

## Workflow

### First Time: Generate

```bash theme={null}
export CROW_API_KEY=ck_...
npx @usecrow/envoy
```

1. Select which directories to scan
2. Envoy reads your code and generates an MCP server
3. Review the generated tools in a conversation loop
4. When satisfied, the server is saved to Crow

### Iterate: Fix

```bash theme={null}
npx @usecrow/envoy fix
```

Loads your existing MCP server and lets you make changes:

* "Add a tool for the `/api/users` endpoint"
* "Fix the auth header on the cancel\_order tool"
* "Remove the get\_all\_orders tool"

### Ship: Deploy

```bash theme={null}
npx @usecrow/envoy deploy
```

Deploys the latest saved version. Your Crow agent immediately starts using the new tools.

## CI Mode

For automated pipelines, use `--ci` for structured JSON output:

```bash theme={null}
CROW_API_KEY=ck_... npx @usecrow/envoy --ci --dirs backend,shared
```

This skips interactive prompts and outputs JSON to stdout.

## Environment Variables

| Variable       | Required | Description                             |
| -------------- | -------- | --------------------------------------- |
| `CROW_API_KEY` | Yes      | Your Crow Envoy API key (`ck_...`)      |
| `CROW_API_URL` | No       | Override API URL (for development only) |

***

## Envoy vs Manual MCP Setup

|                          | Envoy                                    | Manual ([Server-Side MCP](/server-side-mcp)) |
| ------------------------ | ---------------------------------------- | -------------------------------------------- |
| **Setup time**           | Minutes                                  | Hours                                        |
| **MCP knowledge needed** | None                                     | Yes                                          |
| **Hosting**              | Crow hosts it for you                    | You host your own server                     |
| **Updating**             | `npx @usecrow/envoy fix`                 | Edit code, redeploy                          |
| **Best for**             | Getting started fast, standard REST APIs | Custom logic, complex auth, full control     |

<Tip>
  Start with Envoy to get tools working quickly. If you need more control later, you can always switch to a self-hosted MCP server.
</Tip>

***

<CardGroup cols={2}>
  <Card title="Server-Side MCP" icon="server" href="/server-side-mcp">
    Self-hosted MCP server setup (manual approach)
  </Card>

  <Card title="MCP Authentication" icon="key" href="/server-side-mcp-authentication">
    Auth patterns for MCP servers
  </Card>
</CardGroup>