# Reference: command line

> Neutral description of the `mm` executable: flags, positional argument, environment variables, start-up output and exit codes.

## Invocation

```
mm [-config <path>] [-acp] [<path>]
```

| Element | Type | Default | Description |
|---------|------|---------|-------------|
| `-config <path>` | string | `""` | Path of the YAML configuration file. |
| `<path>` | positional | none | Same as `-config`, when `-config` is not given. A second positional argument is an error. |
| `-acp` | bool | `false` | Serve the Agent Client Protocol on stdin/stdout instead of the terminal REPL. |
| `-h` | — | — | Print the flag usage and exit. |

## Configuration file resolution

The first existing source wins.

| Order | Source | Missing file |
|-------|--------|--------------|
| 1 | `-config` flag or positional argument | Error, exit code 1 |
| 2 | `AGENT_CONFIG` environment variable | Error, exit code 1 |
| 3 | `./agent.yaml` | Not an error: built-in defaults are used, the banner shows `config: built-in defaults` |

## Environment variables

| Variable | Effect |
|----------|--------|
| `AGENT_CONFIG` | Path of the configuration file (see above). |
| `AGENT_PROVIDER` | Overrides the `provider` key. |
| `AGENT_MODEL` | Overrides the `model` key. |
| `AGENT_BASE_URL` | Overrides `baseUrl` and disables the fallback probe. |
| `DMR_BASE_URL` | Same as `AGENT_BASE_URL`, for the `dmr` provider only; `AGENT_BASE_URL` wins when both are set. |
| Variable named by `apiKeyEnv` | Holds the API key. Default name: none for `dmr`, `LLAMA_API_KEY` for `llamacpp`. |

## Start-up output

Printed on stdout in terminal mode, on stderr in ACP mode. Dimmed when stdout is a terminal.

| Line | Content |
|------|---------|
| `[warning: …]` | Zero or more probe warnings: server unreachable, model not in the server's list, no chat template, compression that can never trigger. |
| `config: … \| provider: … \| model: … \| ctx: … \| tools: … \| skills: N` | Configuration path, provider name, model identifier, context window with its origin (`config`, `/props`) or `unknown`, declared tool names, number of skills found. |
| `Agent ready. Commands: …` | Terminal mode only. |
| `Shortcut: Ctrl+C …` | Terminal mode only. |

### Example

```
[warning: llamacpp: nothing answers at http://127.0.0.1:8080/v1 — start it: llama-server -m <model.gguf> --jinja --port 8080]
config: agent.llamacpp.yaml | provider: llamacpp | model: jetbrains/mellum2-12b-a2.5b-instruct-gguf-q4_k_m:Q4_K_M | ctx: unknown | tools: bash, read_file, write_file, edit_file | skills: 0
```

## ACP mode specifics

| Aspect | Behaviour |
|--------|-----------|
| stdout | JSON-RPC 2.0 messages only, one per line. |
| stderr | Banner, warnings, `[acp] …` trail, SDK logs. |
| Spinner | Disabled. |
| Relative `skillsDir` | Resolved relative to the directory of the configuration file, when a file was found; otherwise from the working directory, as in terminal mode. |

## Exit codes

| Code | Cause |
|------|-------|
| 0 | `/quit`, `Ctrl+C` at the prompt, end of stdin, or the ACP client closed the connection. |
| 1 | More than one positional argument; configuration load error; engine initialisation error (unknown provider, required key not set). |

## Build and install

| Command | Effect |
|---------|--------|
| `go build -o mm .` | Builds the binary in the current directory. |
| `./install.sh` | Builds `mm` and copies it to `/usr/local/bin`, with `sudo` when the directory is not writable. |
| `go test ./...` | Runs the unit tests. |