Muse "Endo" teardown — Meta's desktop agent has computer‑use built in, gated off

A static teardown of Meta's Muse desktop app for macOS (codename "Endo", bundle
com.meta.endo, v1.0). The finished implementation for a computer‑using agent — seeing the
screen, clicking, typing, running programs, driving a browser — ships in the public build but is
switched off by server‑delivered feature flags.

Found in code, not shipped. Everything here was read out of the released binary and its
Meta‑served config on a single Mac. Flag names, gates, and plans change; some features never
leave the lab. This is observation and commentary, not confirmation from Meta. No app binary is
redistributed here, and no credentials are published.

Read the illustrated report: report/endo-edition-2026-09-17.pdf

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Subject

App	Muse (Meta) for macOS, v1.0
Codename / bundle	Endo / com.meta.endo
Binary	Mach‑O arm64, ~17 MB, Swift + AppKit + SwiftUI
Signature	Developer ID Application: Meta Platforms, Inc. (notarized)
Updater	Sparkle

The five gated capability flags

Muse fetches its feature gates from a Meta config (endo-values-public…json, in the app's cache)
and re‑downloads them on every launch — editing them locally is overwritten within seconds.
Five booleans in the hatch_desktop namespace decide whether the agent can operate the machine,
and all five arrive false:

Flag	Value	Governs
hatch_desktop:enable_computer_control	false	Clicking / typing / controlling the Mac
hatch_desktop:endo_enable_screen_recording	false	The agent seeing the screen
hatch_desktop:enable_browser_automation	false	Driving a browser
hatch_desktop:endo_system_run_sandbox_enabled	false	Sandboxed program execution
hatch_desktop:endo_enable_computer_use_onboarding	false	First‑run "let Muse control your Mac" flow

What the binary already contains behind those flags

• Screen vision — links Apple's ScreenCaptureKit (SCShareableContent, SCStreamConfiguration),
  calls CGPreflightScreenCaptureAccess / CGRequestScreenCaptureAccess, and carries an on‑screen
  computer‑use overlay + an accessibility‑first click mode (_showComputerUseOverlay,
  _preferAXForComputerUseClicks, `[ComputerUs