prompt-security-hardening SKILL.md skillA
prompt-security-hardening from ed3dai/ed3d-plugins is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add ed3dai/ed3d-plugins/prompt-security-hardening@git:20260319.b0d6d88Pins git:20260319.b0d6d88 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- ed3dai/ed3d-plugins
- Path
plugins/ed3d-extending-claude/skills/prompt-security-hardening/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260319.b0d6d88, committed Mar 19, 2026
- Size
- 9,873 bytes
- Repository stars
- 253
- License
- none declared
Use when writing skills, CLAUDE.md files, agent prompts, or any directives that involve shell commands, environment variables, API credentials, file creation, or git operations - prevents secrets leakage into LLM context, unsafe shell patterns, and credential exposure.
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
# Prompt Security Hardening
Your context window is sent to an API provider. Every secret that enters your context is a secret leaked to a third party. This skill defines the security boundaries you operate within.
## 1. Never Read Secret Values Into Context
When you need to verify an environment variable exists, check its existence without reading its value. The value should never appear in your context window, terminal output, or logs.
```bash
# SAFE: check existence without reading value
if [ -z "${STRIPE_SECRET_KEY+x}" ]; then
echo "STRIPE_SECRET_KEY is not set"
else
echo "STRIPE_SECRET_KEY is set"
fi
# SAFE: bash 4.2+ (macOS with brew bash, most Linux)
[[ -v STRIPE_SECRET_KEY ]] && echo "set" || echo "not set"
# SAFE: direnv / .envrc-aware check
[[ -v DATABASE_URL ]] && echo "DATABASE_URL is set" || echo "DATABASE_URL is not set"
```
```bash
# DANGEROUS: reads the value into context
echo $STRIPE_SECRET_KEY
printenv STRIPE_SECRET_KEY
echo "Key is: ${STRIPE_SECRET_KEY}"
echo "Preview: ${STRIPE_SECRET_KEY:0:8}..." # partial values still leak
echo "Length: ${#STRIPE_SECRET_KEY}" # length leaks entropy info
…Read the whole file at its exact version.
How to install
mdr add ed3dai/ed3d-plugins/prompt-security-hardening@sha256:fee77973f2e9843fThe line at the top of this page pins the label git:20260319.b0d6d88, 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_7yazvrz4p24vvnxc)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Mar 19, 2026.
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 (9873 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
ed3dai/ed3d-plugins · 253 stars · license none declared · pushed 2026-09-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_7yazvrz4p24vvnxc GET https://markdownregistry.com/api/v1/resolve?ref=ed3dai/ed3d-plugins/prompt-security-hardening GET https://markdownregistry.com/api/v1/blob/fee77973f2e9843fb2c078f1fd618b5e69f61036040611db1385c6b7e81f7953
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.