app-control SKILL.md skillA
app-control from vellum-ai/vellum-assistant is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add vellum-ai/vellum-assistant/app-control@git:20260611.2d917b0Pins git:20260611.2d917b0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- vellum-ai/vellum-assistant
- Path
assistant/src/config/bundled-skills/app-control/SKILL.md- Versions recorded
- 3
- Latest version
- git:20260611.2d917b0, committed Jun 11, 2026
- First version recorded
- May 3, 2026
- Size
- 3,487 bytes
- Repository stars
- 1,483
- License
- MIT
Drive a specific named macOS app via raw input bypassing the Accessibility tree.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
This skill exposes the `app_control_*` proxy tools for driving a single named macOS application via raw input — keyboard, mouse, screenshot — that bypasses the system Accessibility tree. Use it only when explicitly directed to a specific app where the AX tree is unhelpful (emulators, games, OpenGL canvases, custom-rendered Electron apps). For general macOS UI navigation prefer the `computer-use` skill. Tools in this skill are proxy tools — execution is forwarded to the connected macOS client, never handled locally by the assistant. ## Cadence Take 2-3 actions per turn, then yield with a short narration so the user can interject. Do not chain long sequences without surfacing what you are doing. ## Always observe before acting Call `app_control_observe` before your first input action whenever the screen state matters (e.g. you need to know what is on screen, where a UI element is, or whether the app is even running). Re-observe after actions that may have moved the window or changed visibility. `observe` waits a short settle delay (default ~200ms) before capturing so the target app and the WindowServer can flush pending input and composite a fresh …
Read the whole file at its exact version.
How to install
mdr add vellum-ai/vellum-assistant/app-control@sha256:0d6f28c522b35841The line at the top of this page pins the label git:20260611.2d917b0, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_b2nfxburybi6hjqa)
5 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 3 versions of this file, between May 3, 2026 and Jun 11, 2026, about one every 19 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260611.2d917b0 latest | 2026-06-11 | 2d917b0 | 3,487 B | A | view · diff |
| git:20260503.a8e2849 | 2026-05-03 | a8e2849 | 3,464 B | A | view · diff |
| git:20260503.92ef6dd | 2026-05-03 | 92ef6dd | 3,062 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (3487 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
vellum-ai/vellum-assistant · 1,483 stars · license MIT · pushed 2026-11-08 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_b2nfxburybi6hjqa GET https://markdownregistry.com/api/v1/resolve?ref=vellum-ai/vellum-assistant/app-control GET https://markdownregistry.com/api/v1/blob/0d6f28c522b358410c2523d55cdb5e85a6c06bb1870e74d80384cc5613a934aa
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.