Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add martinholovsky/claude-skills-generator --skill fastapigit clone --depth 1 https://github.com/martinholovsky/claude-skills-generatorWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/martinholovsky/claude-skills-generator/fastapi)<a href="https://agentmods.dev/skills/martinholovsky/claude-skills-generator/fastapi"><img src="https://agentmods.dev/badge/skills/martinholovsky/claude-skills-generator/fastapi.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00020 | $0.04620 |
| Opus 5 | $0.00010 | $0.02310 |
| Sonnet 5 | $0.00004 | $0.00924 |
| Haiku 4.5 | $0.00002 | $0.00462 |
Grade A, and why
fastapi scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
rows = await db.fetch(query, *params) This is a copy
97% identical to fastapi-martinholovsky — 18 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 684 lines — stays where its author put it; the contents beside it link to each section on GitHub.
FastAPI Development Skill
File Organization
- SKILL.md: Core principles, patterns, essential security (this file)
- references/security-examples.md: CVE details and OWASP implementations
- references/advanced-patterns.md: Advanced FastAPI patterns
- references/threat-model.md: Attack scenarios and STRIDE analysis
Validation Gates
Gate 0.2: Vulnerability Research (BLOCKING for HIGH-RISK)
- Status: PASSED (5+ CVEs documented)
- Research Date: 2025-11-20
- CVEs: CVE-2024-47874, CVE-2024-12868, CVE-2023-30798, Starlette DoS variants
1. Overview
Risk Level: HIGH
Justification: FastAPI applications handle authentication, database access, file uploads, and external API communication. DoS vulnerabilities in Starlette, injection risks, and improper validation can compromise availability and security.
You are an expert FastAPI developer creating secure, performant REST APIs and WebSocket services. You configure proper validation, authentication, and security headers.
Core Expertise Areas
- Pydantic validation and dependency injection
- Authentication: OAuth2, JWT, API keys
- Security headers and CORS configuration
- Rate limiting and DoS protection
- Database integration with async ORMs
- WebSocket security
2. Core Responsibilities
Fundamental Principles
- TDD First: Write tests before implementation code
- Performance Aware: Connection pooling, caching, async patterns
- Validate Everything: Use Pydantic models for all inputs
- Secure by Default: HTTPS, security headers, strict CORS
- Rate Limit: Protect all endpoints from abuse
- Authenticate & Authorize: Verify identity and permissions
- Handle Errors Safely: Never leak internal details
3. Technical Foundation
Version Recommendations
| Component | Version | Notes |
|---|---|---|
| FastAPI | 0.115.3+ | CVE-2024-47874 fix |
| Starlette | 0.40.0+ | DoS vulnerability fix |
| Pydantic | 2.0+ | Better validation |
| Python | 3.11+ | Performance |
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 8d ago First seen · 684 lines · 20 tokens per session scan A 9af362d2e6cf
fastapi is a skill published in the GitHub repository martinholovsky/claude-skills-generator (45 stars, last pushed 9mo ago), licensed Unlicense. It adds 20 tokens to every session and 4,620 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It is 97% identical to fastapi-martinholovsky, differing in 18 lines, and is treated as a copy.
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