sandbox-claude-inside SKILL.md skillA
sandbox-claude-inside from arbiterforge/codearbiter is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add arbiterforge/codearbiter/sandbox-claude-inside@git:20261025.1e3e628Pins git:20261025.1e3e628 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- arbiterforge/codearbiter
- Path
plugins/ca-sandbox/skills/sandbox-claude-inside/SKILL.md- Versions recorded
- 4
- Latest version
- git:20261025.1e3e628, committed Oct 25, 2026
- First version recorded
- Jun 20, 2026
- Size
- 9,720 bytes
- Repository stars
- 152
- License
- AGPL-3.0
Run Claude Code INSIDE a ca-sandbox box (`--with-claude`). Routed to when the user wants an agent loop running against an isolated, ephemeral sandbox rather than the host. Authenticates via an env-injected CLAUDE_CODE_OAUTH_TOKEN with no host bind of ~/.claude; the image pins the CLI and disables the autoupdater; HOME is backed by a named volume so the .claude state persists across restart. Five gated phases — posture, image, token, run, teardown. The hard default is offline or…
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
# sandbox-claude-inside
Put Claude Code in the box, not the box on your machine. `--with-claude` runs the
CLI inside a host-FS-isolated ca-sandbox container, authenticating from an
env-injected token with no host bind of `~/.claude` — the mechanism proven by
Spike B (`.codearbiter/spikes/ca-sandbox-claude-auth.md`, CONFIRM-07). It is the
deliberately-hardened lane: a token in a box is stealable, so the posture is locked
down by construction (offline or Anthropic-only egress, token volume never shared
with untrusted code), never left to operator discipline.
## Pre-flight
Read these, or STOP and surface the gap — never guess the token source, the egress
posture, or the persistence mechanism:
- `${CLAUDE_PROJECT_DIR}/.codearbiter/spikes/ca-sandbox-claude-auth.md` — the
proven auth path (env token → real `401` on a dummy), the named-volume HOME
persistence mechanism, and the load-bearing caveat that fixes the hard default.
- `${CLAUDE_PROJECT_DIR}/.codearbiter/spikes/ca-sandbox-egress.md` — why the
egress allowlist is EXPERIMENTAL (CDN drift + DNS-exfil hole), so `offline` is
the only GUARANTEED posture for a token-bearing box.
…Read the whole file at its exact version.
How to install
mdr add arbiterforge/codearbiter/sandbox-claude-inside@sha256:40f5b0c24192f59cThe line at the top of this page pins the label git:20261025.1e3e628, 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_j6awxgjfigb5biml)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 4 versions of this file, between Jun 20, 2026 and Oct 25, 2026, about one every 42 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261025.1e3e628 latest | 2026-10-25 | 1e3e628 | 9,720 B | A | view · diff |
| git:20260726.8224618 | 2026-07-26 | 8224618 | 9,658 B | A | view · diff |
| git:20260725.4f7a909 | 2026-07-25 | 4f7a909 | 8,958 B | A | view · diff |
| git:20260620.6a1de36 | 2026-06-20 | 6a1de36 | 8,281 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 (9720 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
arbiterforge/codearbiter · 152 stars · license AGPL-3.0 · pushed 2026-11-07 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_j6awxgjfigb5biml GET https://markdownregistry.com/api/v1/resolve?ref=arbiterforge/codearbiter/sandbox-claude-inside GET https://markdownregistry.com/api/v1/blob/40f5b0c24192f59cb09b6da6ab119096d9ae6abb27a94f29a6dbb592defc3748
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.