# CLI reference

The `luca` CLI uses the same public data as the REST and MCP endpoints.
The script runs with Node.js 18 or later. Standalone binaries need no Node.js install.

| Command | Function |
| --- | --- |
| `overview` | Get product topics and source links |
| `search --query TEXT` | Search reviewed product facts |
| `answer --question TEXT` | Answer from reviewed facts with source links |
| `assess --goal GOAL ...` | Get a nonbinding starting point |
| `next --goal GOAL` | Get official next steps |
| `paths` | Compare three product paths |
| `conflicts` | Read unresolved public claims |
| `topic --id ID` | Read one sourced topic and its review state |
| `mcp` | Run a local stdio MCP server |

Use `--brand pay` or `--brand plus` to select the product.
Use `--base URL` or `LUCA_BASE_URL` to use a test deployment.
The packaged CLI uses the public Pages previews by default until the product hosts have DNS.
The CLI calls the public REST and MCP routes without a password.
Options can appear before or after the command.

`mcp` writes JSON-RPC messages to stdout.
It writes errors to stderr.
Use an absolute executable path in each MCP client configuration.