acp SKILL.md skillA
acp 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/acp@git:20260916.3f5987ePins git:20260916.3f5987e 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/acp/SKILL.md- Versions recorded
- 8
- Latest version
- git:20260916.3f5987e, committed Sep 16, 2026
- First version recorded
- Jun 30, 2026
- Size
- 11,641 bytes
- Repository stars
- 1,467
- License
- MIT
Set up, authenticate, and run external coding agents (Claude Code, Codex) via the Agent Client Protocol.
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
ACP agent orchestration - spawn external coding agents (Claude Code, Codex) to work on tasks via the Agent Client Protocol. Each agent runs as its own subprocess speaking ACP over stdio and streams results back into the conversation. ## Usage Use `acp_spawn` to delegate a coding task to an external agent. The agent runs as a subprocess speaking the ACP protocol over stdio and streams results back. Users can refer to agents by natural names: "claude code", "codex cli", and "openai codex" all resolve to the canonical `claude` and `codex` ids (unless the user's config defines an agent literally keyed by that name, which always wins). ## Choosing a model Claude runs on Opus unless the user names a model; every other agent starts on its own default. When the user does name one, pass it as `model` on `acp_spawn`. Model names are the agent's own vocabulary, not Assistant model ids: an alias such as `default`, `sonnet`, `opus`, `haiku`, `fable`, or `opusplan` for Claude, or a full model id. Pass what the user said and let the agent resolve it. …
Read the whole file at its exact version.
How to install
mdr add vellum-ai/vellum-assistant/acp@sha256:856f7eb970aec89fThe line at the top of this page pins the label git:20260916.3f5987e, 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_7xgedwcxixms42wl)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 8 versions of this file, between Jun 30, 2026 and Sep 16, 2026, about one every 11 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260916.3f5987e latest | 2026-09-16 | 3f5987e | 11,641 B | A | view · diff |
| git:20260911.15f1f50 | 2026-09-11 | 15f1f50 | 11,558 B | A | view · diff |
| git:20260911.4590130 | 2026-09-11 | 4590130 | 11,192 B | A | view · diff |
| git:20260906.c6e2a61 | 2026-09-06 | c6e2a61 | 10,198 B | A | view · diff |
| git:20260901.8c34e6d | 2026-09-01 | 8c34e6d | 9,998 B | A | view · diff |
| git:20260807.cd12932 | 2026-08-07 | cd12932 | 9,504 B | A | view · diff |
| git:20260717.2397702 | 2026-07-17 | 2397702 | 9,646 B | A | view · diff |
| git:20260630.c2cf9cc | 2026-06-30 | c2cf9cc | 8,051 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 (11641 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 · 1,467 stars · license MIT · pushed 2026-10-29 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_7xgedwcxixms42wl GET https://markdownregistry.com/api/v1/resolve?ref=vellum-ai/vellum-assistant/acp GET https://markdownregistry.com/api/v1/blob/856f7eb970aec89fd8095cb58315df7c675c81903a1add2b9b8962151a4ac27e
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.
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