Interceptor macOS
Agent-operator skill for the macOS surface of Interceptor. Use the interceptor macos * CLI to drive native macOS applications: AX trees, OS-level trusted input, capture / vision / speech / NLP / Apple Events, monitor-and-replay, overlays. Use interceptor macos cdp / interceptor macos cdp app for Electron app web contents, and interceptor macos runtime for in-process native app runtime control. For content inside a browser tab load interceptor-browser instead.
The macOS bridge is a Swift daemon launched as a LaunchAgent / .app bundle. It uses Apple frameworks including Accessibility, ScreenCaptureKit, AVFoundation, Speech and Vision. Some existing capture and runtime paths also use private CGS symbols or injected runtime access. Check the surface reference and actual capability result; public framework support does not guarantee every private path works on every OS release.
This installed skill is self-contained. Source checkouts also have AGENTS.md, but packaged users may only have the skill directory below /Library/Application Support/Interceptor/skills.
Installed extensions may add capabilities under interceptor macos <prefix> <cmd>. Each carries its own skill (interceptor-ext-<name>); this skill does not describe them. Run interceptor extensions list to see what is installed.
Fast Path
interceptor status # 1. Confirm daemon + bridge are alive
interceptor macos trust # 2. Confirm TCC permissions granted
interceptor macos open "Finder" # 3. Tree + windows (background — does NOT raise Finder)
interceptor macos read # 4. AX tree + frontmost info
interceptor macos act e5 # 5. AX press of ref e5 — no focus change
interceptor macos act e3 "hello" # 6. AX value-set of ref e3 — no focus change
Treat eN refs as short-lived. AX state can change between calls; re-read before acting.
The One Rule
Only two commands move focus: interceptor macos app activate <app> and interceptor macos open <app> --activate. Everything else is background-first by contract — open (without --activate), all input verbs, all reads, capture, AX, menu, intent dispatch, scroll, drag, vision, overlays. If you call any other command and the user's frontmost app changes, that is a bug — file it.
The user is on this Mac too. Assume the person is working while you work. Never run either focus command to make your own work easier or to test something. Use one only when the user asks for the app to come forward, or when the action truly cannot be done in the background, and then say so first, keep it to one fast batch, and put back the frontmost app and the cursor.
What is truly foreground-only today: launching an app that is not running (it can come forward even from open without --activate, and an app updater can raise a password prompt), and a click or drag on a minimized window or hidden app. Everything else has a background route: refs, --app / --pid / --window, and interceptor click <ref> --trusted for a page in an unfocused browser window.
Full contract + verb inventory + worked examples + pitfalls: references/background-first.md.
Workflows
Each workflow is a complete self-contained "you are doing X" procedure. Open the file when the task matches.
References
| File | Topic |
|---|
references/background-first.md | Full Background-First contract, verb inventory, reflexes-to-drop, pitfalls |
references/accessibility-and-input.md | AX tree mechanics, input routing, window control, credential delivery by name (--secret) |
references/capture-and-vision.md | ScreenCaptureKit + CGS capture, Vision OCR, audio intelligence |
references/advanced-domains.md | Apple Events, container runtime, OS log, fs, URL fetch, file watch |
references/jsc-host.md | Plain JavaScriptCore host capabilities, flags, scope rules, and pitfalls |
references/monitor-and-replay.md | Native monitor sessions, replay plans, event sources |
references/command-catalog.md | Full macOS command surface with flags and examples |
references/permissions.md | TCC permissions, microphone re-poll, Dock-icon notes |
references/cdp-app.md | Electron/Chromium desktop apps via interceptor macos cdp / interceptor macos cdp app |
references/native-agent.md | In-process native app runtime control via interceptor macos runtime |
When To Switch Surfaces
If the target is inside a browser page (DOM, network, SPA state, browser monitor, scene graph of a rich editor) - load interceptor-browser instead.
If the target is inside an Electron/Chromium desktop app's web contents (Slack, VS Code, Notion, Descript, etc.) - use references/cdp-app.md, not AX screenshots.
If the target is inside a native app's runtime (AppKit/SwiftUI object graph, selector calls, rendered text changes, hooks, MapKit state) - use references/native-agent.md. AX is still the fallback projection when the in-process agent is unavailable.
Do Not Default To Troubleshooting
- User wants a macOS task completed → run Interceptor commands.
- User wants Interceptor fixed, installed, or explained → that's a separate task; ask before diving into repo state.
- Inside the Interceptor repo, use this skill for live macOS validation, not as the primary source of repo-development instructions.