# `once mcp`

Expose Once's graph and memory queries to a coding agent

## Synopsis

```text
once mcp [OPTIONS]
```

## Description

Speaks the Model Context Protocol over standard input and output so a coding harness can discover schemas and starters, validate and edit typed graphs, inspect or execute annotated scripts, run graph capabilities, and query project evidence without scraping prose. Mounts inspection tools by default; pass `--allow-run` to expose manifest editing, test, build, run, and runtime session tools.

## Options

| Flag | Value | Default | Description |
| --- | --- | --- | --- |
| `--workspace` | `<DIR>` |  | Workspace root the agent tools resolve targets against. Defaults to the value of the global `-C/--directory` flag (or the current directory) |
| `--allow-run` | (flag) | `false` | Advertise and allow state-changing editing and execution tools |
| `-C, --directory` | `<DIR>` |  | Project root. Defaults to the current directory; the cache lives under `<project>/.once/`. Mirrors `make -C` |
| `--format` | `<FORMAT>` | `human` | Output format for Once's structured data (`cache stats`, `run`/`exec` trailers). Defaults to a human-readable rendering; pass `json` or `toon` to get machine-parseable output for scripting and for agent consumers |
| `-v, --verbose` | (flag) | `0` | Increase log verbosity. Repeat for more (-v: info, -vv: debug, -vvv: trace). Overridden by `RUST_LOG` |
| `-q, --quiet` | (flag) | `false` | Suppress human-mode success and progress trailers. Errors and the structured envelope of `--format json`/`toon` still print. Mirrors the `-q` flag of common build tools |
| `--list` | (flag) | `false` | Print the command surface at the current command depth |
| `--memory-limit` | `<SIZE>` |  | Maximum memory scheduling budget for local actions. Defaults to two thirds of the memory visible to the host or container |