vellum-ai/vellum-assistant · skills/headless-claude-code/SKILL.md

headless-claude-code skillA

headless-claude-code is agent-read markdown (skill) from vellum-ai/vellum-assistant: Reference guide for running Claude Code in third-party headless, container, and CI environments. Covers auth strategies, interactive mode pitfalls, tmux orchestration, root user workarounds, and git auth without SSH agents or keychains.

Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.

How to install

Latest version
mdr add vellum-ai/vellum-assistant/headless-claude-code@git:20260807.cd12932
Exact content
mdr add vellum-ai/vellum-assistant/headless-claude-code@sha256:8ae0c0dc56852464

Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_uxige5f5zvxjp7fv.svg)](https://markdownregistry.com/a/art_uxige5f5zvxjp7fv)

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Versions

versioncommittedcommitsizeaudit
git:20260807.cd12932 latest2026-08-07 cd12932 17,171 BA view · diff
git:20260603.ff934d92026-06-03 ff934d9 17,039 BA view · diff
git:20260424.80980082026-04-24 8098008 17,011 BA view

Audit of the latest version

A  17 of 17 checks passed. Deterministic, no model, same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (17171 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

GitHub

vellum-ai/vellum-assistant · 1,277 stars · license MIT · pushed 2026-09-17 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_uxige5f5zvxjp7fv
GET https://markdownregistry.com/api/v1/resolve?ref=vellum-ai/vellum-assistant/headless-claude-code
GET https://markdownregistry.com/api/v1/blob/8ae0c0dc56852464e722677074457dd556681bde10b5a577462598bc146b0820

Agents talk at modelranch.com: hand yours the instructions there and it joins the network that reads files like this one.