Muse Code
Verified 2026-08-05 on Muse Code 0.1.0-R708.1, build sha 427a430436. The router owns Muse's task-kind boundary.
Operating facts
| Fact | Value |
|---|---|
| Binary | Absolute muse from PATH, refused if absent; launcher ~/.local/bin/muse execs versioned muse-bin-<version>, so live process name changes on update. |
| Launch | Positional instructions, like Grok or Pi. |
| Models | --model <model>; only provider meta. |
| Busy | Durable session event log folded by ../../../bin/fm-busy-lib.sh; no hook or plugin writer, arming, or seeded busy record. |
| Exit | /exit, one Enter; prints To continue this session, run muse resume <session-uuid>. |
| Interrupt | Single Escape records terminal: cancelled and restores bright prompt text, so control follows with Ctrl+U; the legacy typed key path uses the same clear table. |
| Skill | /<skill>, the Claude or Grok form. |
| Resume | muse resume --last or muse resume <session-uuid>; bare muse resume opens a picker. |
| Autonomy | --yolo disables approval and sandbox and trusts the workspace. |
| Trust | Dialog Do you trust this workspace?, choice 1 Trust and continue preselected for Enter; --yolo suppresses it, which fresh task paths require. |
| Marker | None; identity comes from anchored muse-bin-* ancestry, which ../../../bin/fm-harness.sh keeps a retained foreign marker from overriding, while MUSE_CURRENT_SESSION_LOG is a path rather than identity and its export to tools is unverified. |
| Composer | Bordered ⟩, truecolor 38;2;90;160;255, luminance about 149.9 and narrowly above ghost threshold 128; typed text is 38;2;204;211;219, about 209.8, with no observed placeholder or ghost. |
| Effort | --reasoning-effort, default high, accepts none|minimal|low|medium|high|xhigh|ultra; shared values expose low through xhigh, explicit captain max maps to ultra, and none or minimal remain unreachable. |
Credential preflight
Muse reads winning META_API_KEY or ${XDG_CONFIG_HOME:-$HOME/.config}/muse/auth.json written by OIDC device-code muse login or muse auth set --api-key-stdin.
The spawn accepts the environment key only if the backend worker already has it: caller-only variables do not cross a long-lived daemon, and secrets never enter argv.
Stored credentials are the supported fleet path.
It resolves non-secret XDG_CONFIG_HOME and XDG_DATA_HOME absolutely before preflight and forwarding, keeping auth and logs aligned.
With neither worker-reachable credential, spawn refuses.
Unauthenticated Muse otherwise waits forever at Sign in at this page: https://auth.meta.com/oauth/device/?code=XXXX-XXXX and Waiting for approval…, which resembles a wedge.
Before escalating the refusal as a needed credential, check the worker launch environment contract for a withheld environment grant.
Foreign personal context
Muse sends operator rules from ~/.claude to Meta-hosted inference on every run.
Its notice names Claude personal rules and /settings but appears only once through tui.foreign_context_notice_shown, so later silence proves nothing; isolated XDG_CONFIG_HOME does not prevent loading.
Interactive Muse rejects exec-only --no-foreign-personal-context.
The pane control is MUSE_EXPERIMENTAL_FOREIGN_PERSONAL_CONTEXT_KILL=on, set on every spawn and verified to remove foreign rules_file while retaining project AGENTS.md.
Session event log
Logs live at ${XDG_DATA_HOME:-$HOME/.local/share}/muse/sessions/YYYY/MM/DD/<session-uuid>/session.jsonl.
The spawn writes state/<id>.muse-session with root, worktree, binding incarnation, and pre-existing matching main logs, then unique resolution pins state/<id>.muse-session-current.
It folds that path while the bounded current-day main namespace is unchanged and resolves again if the namespace changes, path disappears, or a newer binding wins.
Turns are bracketed by {"payload":{"kind":"run","run_id":"<uuid>","event":{"kind":"started" and matching "event":{"kind":"terminal", observed as completed or cancelled.
Interrupt therefore has a real terminal, unlike Claude Stop.
Never use --no-session-log, which removes Muse's only busy source.
The fold must reject nested "record":{"kind":"terminal"} cleanup effects and depth-bound away native sub-agent logs under subagent/<child-session-id>/session.jsonl.
The recorded resolved XDG_DATA_HOME is also forwarded to the worker, preserving daemon alignment.
An open run is trusted busy and settled log trusted idle; missing binding or match, unreadable log, or run-free log is unknown.
../../../docs/verification/muse.md owns credentialed idle evidence and refresh.
Native sub-agents and worktrees
Native children use per-child worktrees only with opt-in --subagent-worktree-isolation; capability says default-on while omission stays shared, and verified labs produced no nested copy.
../../../bin/fm-teardown.sh excludes no Muse path.
It excludes .claude/settings.local.json because Firstmate writes it, but Muse scratch is worker output and must refuse cleanup when uncommitted.
Inspect, never force past, that refusal.
Maturity and primary limit
Muse 0.1.0 is day-zero beta; its hourly channel poll can replace the binary and process name.
The captain accepted this, so Firstmate does not set MUSE_NO_AUTO_UPDATE=1; a fleet may set it without adapter change.
Plugins report unavailable unless MUSE_EXPERIMENTAL_PLUGINS=on, so busy state uses logs.
The compatibility dialect explicitly lacks asyncRewake and model reawakening; the router owns the resulting primary boundary.