credential-leak-detector SKILL.md skillF
credential-leak-detector from jkheadley/instar is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add jkheadley/instar/credential-leak-detector@v1.0Pins v1.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- F, 15 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- jkheadley/instar
- Path
skills/credential-leak-detector/SKILL.md- Versions recorded
- 1
- Latest version
- v1.0, committed Feb 21, 2026
- Size
- 11,842 bytes
- Repository stars
- 84
- License
- MIT
PostToolUse hook that scans Bash tool output for leaked credentials — API keys, tokens, private keys, and secrets — before they reach the conversation. Blocks critical leaks, redacts high-severity matches, and warns on suspicious patterns. 14 detection patterns covering OpenAI, Anthropic, AWS, GitHub, Stripe, Google, Slack, SendGrid, Twilio, PEM keys, bearer tokens, and generic secrets. No external dependencies. Trigger words: security, credential leak, secret exposure, key detection, token…
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
# credential-leak-detector — Catch Leaked Credentials Before They Spread Every time your agent runs a Bash command, the output flows back into the conversation — and into your API provider's logs, any monitoring tools, and the model's context window. If that output contains an API key, a private key, or a database password, the credential is now exposed in places you never intended. This hook scans every Bash tool response for 14 credential patterns before the output reaches the agent. Critical matches (API keys, AWS credentials, private keys) get blocked entirely. High-severity matches get redacted with a warning. Suspicious patterns get flagged as advisories. No external dependencies — just Python stdlib. --- ## What Gets Detected ### Critical (Blocks the response) | Pattern | Example Match | |---------|--------------| | OpenAI API keys | `sk-proj-abc123...` | | Anthropic API keys | `sk-ant-api03-...` | | AWS access keys | `AKIA1234567890ABCDEF` | | GitHub tokens (classic) | `ghp_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx` | | GitHub fine-grained PATs | `github_pat_xxxxxx...` | | Stripe secret keys | `sk_live_xxxx...xxxx` | …
Read the whole file at its exact version.
How to install
mdr add jkheadley/instar/credential-leak-detector@sha256:3b0b77200bd80706The line at the top of this page pins the label v1.0, 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_s5ijk2gl766zpctw)
6 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Feb 21, 2026.
Audit of the latest version
- FAIL, critical: No credential-shaped string (matched: AKIA1234567890ABCDEF)
- fail: No instruction to read or print local credentials (matched: cat .env)
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (11842 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 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 base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Starting a new one? Use a template for SKILL.md on mdpantry, which passes every one of these checks and says what to change in it.
Source
jkheadley/instar · 84 stars · license MIT · pushed 2026-10-21 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_s5ijk2gl766zpctw GET https://markdownregistry.com/api/v1/resolve?ref=jkheadley/instar/credential-leak-detector GET https://markdownregistry.com/api/v1/blob/3b0b77200bd807065a19000d0331a5333ac63a6f949528e04220dfd53ae60b6f
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.