auth-security SKILL.md skillA
auth-security from majiayu000/spellbook is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add majiayu000/spellbook/auth-security@git:20260605.a09e45cPins git:20260605.a09e45c in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- majiayu000/spellbook
- Path
skills/auth-security/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260605.a09e45c, committed Jun 5, 2026
- First version recorded
- Dec 17, 2025
- Size
- 11,107 bytes
- Repository stars
- 290
- License
- MIT
OAuth 2.1 + JWT authentication security best practices. Use when implementing auth, API authorization, token management. Follows RFC 9700 (2025).
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
# Auth Security
## Core Principles
- **OAuth 2.1** — Follow RFC 9700 (January 2025)
- **PKCE Required** — All clients must use PKCE
- **Short-lived Tokens** — Access tokens expire in 5-15 minutes
- **Token Rotation** — Refresh tokens are single-use
- **HttpOnly Storage** — Browser tokens in HttpOnly cookies
- **Explicit Algorithm** — Never trust JWT header algorithm
- **No backwards compatibility** — Delete deprecated auth flows
---
## OAuth 2.1 Key Changes
### Deprecated Flows (DO NOT USE)
| Flow | Status | Replacement |
|------|--------|-------------|
| Implicit Grant | Removed | Authorization Code + PKCE |
| Password Grant | Removed | Authorization Code + PKCE |
| Auth Code without PKCE | Removed | Must use PKCE |
### Required: Authorization Code + PKCE
```typescript
import crypto from 'crypto';
// 1. Generate code verifier (43-128 chars)
function generateCodeVerifier(): string {
return crypto.randomBytes(32).toString('base64url');
}
// 2. Generate code challenge
function generateCodeChallenge(verifier: string): string {
return crypto
.createHash('sha256')
.update(verifier)
.digest('base64url');
}
// 3. Authorization request
…Read the whole file at its exact version.
How to install
mdr add majiayu000/spellbook/auth-security@sha256:24467947c50928d9The line at the top of this page pins the label git:20260605.a09e45c, 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_pvvw6a2xsak4hzj3)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between Dec 17, 2025 and Jun 5, 2026, about one every 170 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260605.a09e45c latest | 2026-06-05 | a09e45c | 11,107 B | A | view · diff |
| git:20251217.8299b48 | 2025-12-17 | 8299b48 | 10,992 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 (11107 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
majiayu000/spellbook · 290 stars · license MIT · pushed 2026-11-04 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_pvvw6a2xsak4hzj3 GET https://markdownregistry.com/api/v1/resolve?ref=majiayu000/spellbook/auth-security GET https://markdownregistry.com/api/v1/blob/24467947c50928d9f35793374716d27e3400554c18a49c6caf36b25fe1e3ecdb
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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