# Secure FastAPI APIs with JWT Auth

FastAPI teams need consistent JWT authentication that protects private endpoints without leaking sensitive details. This skill guides token validation, access control, error handling, and testing for secure REST APIs.

## Install

```bash
npx skillstore add claude/abdul-haseeb360-api-jwt-authenticator
```

## Metadata

- - Status: approved
- - Slug: abdul-haseeb360-api-jwt-authenticator
- - Version: 1.0.0
- - Author: Claude
- - GitHub username: Abdul-Haseeb360
- - License: MIT
- - Repository: https://github.com/Abdul-Haseeb360/Hackathon-II-AI-Native-Systems/tree/main/.claude/skills/api-jwt-authenticator
- - Ref: main
- - Supported tools: Claude, Codex, Claude Code
- - Risk level: low
- - Quality score: 77
- - Quality tier: bronze
- - Public page: https://skillstore.pages.dev/skills/abdul-haseeb360-api-jwt-authenticator
- - Manifest: https://skillstore.pages.dev/api/skills/abdul-haseeb360-api-jwt-authenticator/manifest

## Capabilities

- Explains when JWT authentication is appropriate for FastAPI APIs.
- Defines expected Authorization header and JWT claim requirements.
- Outlines signature, expiration, issuer, and audience validation checks.
- Describes user identity checks for resource ownership.
- Covers 401 and 403 error handling without sensitive disclosure.
- Lists testing scenarios for invalid tokens, expired tokens, and roles.

## Use Cases

- Protect FastAPI endpoints: Add JWT validation requirements to private API routes and reject invalid or expired tokens.
- Review access control design: Check that token identity and resource ownership rules prevent users from accessing other users' data.
- Plan authentication tests: Create test coverage for invalid tokens, expired tokens, role limits, and expected error responses.

## Prompt Templates

### Map JWT requirements

```
Use this skill to list the JWT authentication requirements for my FastAPI API. Include required headers, claims, and error responses.
```

### Design protected routes

```
Use this skill to design JWT protection for these FastAPI routes. Identify which routes need authentication and which need role checks.
```

### Review access control

```
Use this skill to review my FastAPI JWT access control plan. Focus on user identity checks, resource ownership, and safe error messages.
```

### Build a test strategy

```
Use this skill to create a JWT authentication test strategy for FastAPI. Cover invalid signatures, expired tokens, missing claims, and RBAC failures.
```

## Limitations

- Provides conceptual guidance, not a complete implementation package.
- Does not choose a specific JWT library or signing algorithm.
- Does not cover OAuth, API keys, or session authentication in depth.
- Requires developers to manage secrets and HTTPS configuration separately.

## Best Practices

- Require HTTPS in production before accepting bearer tokens.
- Store signing secrets in environment variables or a secure vault.
- Validate signatures, expiration, issuer, audience, and required claims before trusting token data.

## Anti Patterns

- Do not accept tokens from query parameters for protected API calls.
- Do not log raw JWTs or signing secrets during authentication failures.
- Do not rely only on a role claim when resource ownership must also be checked.

## Security Audit

- - Safe to publish: true
- - Audited at: 2026-06-28T03:48:05.686\+00:00
- - Summary: Static analysis flagged Markdown backticks, JWT terminology, and HTTP authentication documentation as suspicious patterns. Review found no executable code, shell invocation, prompt injection, malware behavior, or data exfiltration in SKILL.md. The skill is a conceptual security guide and is safe to publish with low residual risk.

## Stats

- - Views: 171
- - Downloads: 7
- - Favorites: 1
- - Popularity score: 0