At a glance
Meta's terminal and CI coding agent with repository tools, default-on approvals and OS sandboxing, persistent memory, compaction, resumable sessions, goals, subagents, skills, hooks, and MCP.
Good choice if
- Meta Model API users who want a Muse Spark agent for terminal and CI work
- Long tasks using goals, compaction, persistent memory, and resumable sessions
- Parallel workflows with subagents, observer agents, worktrees, skills, hooks, and MCP
Check before choosing
- The beta ships as a proprietary binary, so evidence is documentation-verifiable without a public implementation audit
- The Meta and Muse Spark path uses usage-based billing; model performance and benchmark results do not establish harness quality, and no built-in browser or non-Meta provider is documented
- Default on-request approval passes commands outside a small dangerous set and relies on the sandbox; --yolo disables both controls and trusts repository instructions
See 3 more considerations
- MCP tools run outside the filesystem and network sandbox, while hooks bypass both sandbox and approval
- Worktree isolation is opt-in and falls back to a shared workspace outside Git; it does not contain processes or external effects
- Resume rebuilds session state but not files; effects interrupted in flight retain an unknown outcome and require verification before retry, and no file checkpoint or rollback mechanism is documented; committed memory is injected before workspace trust