git:20260816.9c5228d to git:20260816.21ed22e

---

name: muse-delegation

description: Delegates tasks to Meta's Muse Code CLI (muse) via delegation-core. Use when delegation-core selects Muse or repository-scale work needs a 1M-token context.

alwaysApply: false

category: delegation-implementation

tags:

- muse

- meta

- cli

- delegation

- large-context

dependencies:

- delegation-core

tools:

- muse

- delegation_executor.py

usage_patterns:

- muse-cli-integration

- repository-scale-analysis

- headless-ci-execution

complexity: intermediate

model_hint: standard

estimated_tokens: 600

references:

- delegation-core/shared-shell-execution.md

---

## Table of Contents

- [Overview](#overview)

- [When To Use](#when-to-use)

- [When NOT To Use](#when-not-to-use)

- [Prerequisites](#prerequisites)

- [Quick Start](#quick-start)

- [Smart Delegation](#smart-delegation)

- [Muse-Specific Details](#muse-specific-details)

- [Exit Criteria](#exit-criteria)

# Muse Code Delegation

## Overview

Muse Code is Meta's terminal coding agent, released August 2026 and

built on Muse Spark 1.2. It runs either as an interactive TUI or as a

one-shot headless command, and the headless form is what delegation

uses.

The binary is `muse`. Meta publishes no npm or PyPI package for it:

the documented install is a script served from Meta's own domain.

## When To Use

- `delegation-core` selected `muse` for the task

- Repository-scale reading where Muse Spark 1.2's 1M-token context

helps

- Work that should run unattended, since `muse exec` is designed for

CI

## When NOT To Use

- `META_API_KEY` is unset and the run cannot be interactive

- A specific model must be selected. Meta documents no `--model` flag

for `exec`, so the CLI default stands

- Structured output is required. No output-format flag is documented

for `exec`

## Prerequisites

### Installation

```bash

curl -fsSL https://dev.meta.ai/install.sh | sh

```

This pipes a remote script into a shell. Read

<https://dev.meta.ai/docs/muse-code> before running it. The guided

installer offers the same command and shows its source first:

```bash

make -C plugins/conjure delegate-setup

```

### Authentication

Meta documents the environment variable as the CI path:

```bash

export META_API_KEY="<your-key>"

muse exec "Run the test suite and summarize failures."

```

A bare `muse` prompts for browser sign-in on first run, which is not

usable unattended. There is no `muse auth status` command, so the

service declares an empty auth probe and verification checks

`META_API_KEY` instead.

## Quick Start

### Using the shared delegation executor

```bash

uv run python scripts/delegation_executor.py muse "Summarize this module" \

--files src/

```

### Through the Makefile

```bash

make -C plugins/conjure delegate-muse PROMPT='Explain this design'

```

### Direct CLI usage

```bash

muse exec "Explain the retry logic in this package"

```

## Smart Delegation

`muse` declares the strengths `code_execution` and `large_context`,

It declares no model ids, so `smart_delegate` leaves model selection

to the CLI rather than passing a flag Meta does not document.

## Muse-Specific Details

| Property | Value |

|----------|-------|

| Binary | `muse` |

| Headless form | `muse exec <prompt>` |

| Prompt delivery | positional, no flag |

| Version probe | `muse --version` |

| Auth probe | none published |

| Auth | `META_API_KEY` |

| File context | inlined, no `@path` syntax |

The prompt is positional. A command ending in a flag would consume the

prompt as that flag's value, which is why the service config sets

`prompt_flag=None` and the War Room expert's command ends at

`muse exec`.

Two claims circulating in third-party guides are not in Meta's own

documentation and are not relied on here: a `--json` flag streaming

JSONL events to stdout, and `muse auth set --api-key-stdin`. The

confirmed JSONL reference is to on-disk session logs. Treat both as

unverified until Meta documents them.

## Exit Criteria

- [ ] `muse` resolves on PATH and `muse --version` answers

- [ ] `META_API_KEY` is set, or the operator accepted an interactive

sign-in

- [ ] The built command is `muse exec <prompt>` with the prompt as the

final argument and no prompt flag before it

- [ ] File context was inlined into the prompt rather than passed as

`@path` references

- [ ] Output saved to `delegations/muse/YYYYMMDD_HHMMSS.md`

- [ ] This skill ran because `delegation-core` selected `muse`, not by

default