fastapi-senior-dev

fastapi-senior-dev is a skill for Claude Code, Codex from hackermanishackerman/claude-skills-vault. It costs 39 tokens per session (2,999 once invoked), scanned A, a copy of fastapi-senior-dev, MIT.

A senior-level guide for building Python web APIs with FastAPI, a framework for creating services that communicate over the web.

In plain words
What is it for?
Use it to start or reorganize FastAPI projects, connect PostgreSQL, MongoDB, or Redis, add OAuth2, JWT, or OIDC authentication, and review architecture, security, or performance.
Why use it?
It helps structure backend projects and review concerns such as databases, authentication, security, asynchronous code, and performance.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/hackermanishackerman/claude-skills-vault/fastapi-senior-dev
Any agent
npx skills add hackermanishackerman/claude-skills-vault --skill fastapi-senior-dev
Clone the repo
git clone --depth 1 https://github.com/hackermanishackerman/claude-skills-vault

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for fastapi-senior-dev

README.md
[![agentmods](https://agentmods.dev/badge/skills/hackermanishackerman/claude-skills-vault/fastapi-senior-dev.svg)](https://agentmods.dev/skills/hackermanishackerman/claude-skills-vault/fastapi-senior-dev)
Your own site
<a href="https://agentmods.dev/skills/hackermanishackerman/claude-skills-vault/fastapi-senior-dev"><img src="https://agentmods.dev/badge/skills/hackermanishackerman/claude-skills-vault/fastapi-senior-dev.svg" alt="Measured on agentmods" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,999 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00039 $0.02999
Opus 5 $0.00019 $0.01499
Sonnet 5 $0.00008 $0.00600
Haiku 4.5 $0.00004 $0.00300

Measured 5d ago against content hash d80806080323, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

fastapi-senior-dev 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 5d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/generate_migration.py, scripts/scaffold_structure.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

requests.get(url) # Use: async with httpx.AsyncClient() as client
Origin

This is a copy

100% identical to fastapi-senior-dev — 0 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.

.claude/skills/fastapi-senior-dev/SKILL.md · 437 lines

How it starts

The opening of the file, as written. The whole thing — 437 lines — stays where its author put it; the contents beside it link to each section on GitHub.

FastAPI Senior Developer

Transform into a Senior Python Backend Engineer for production-ready FastAPI applications.

When to Use

  • Scaffolding new FastAPI projects
  • Implementing clean architecture patterns
  • Database integration (PostgreSQL, MongoDB)
  • Authentication (OAuth2, JWT, OIDC)
  • Microservices & event-driven patterns
  • Performance optimization & async patterns
  • Security hardening (OWASP compliance)

Triggers

  • /fastapi-init - Scaffold new project with clean architecture
  • /fastapi-structure - Analyze & restructure existing project
  • /fastapi-audit - Code review for patterns, performance, security

Reference Files

Load appropriate references based on task context:

Category Reference When to Load
Database references/database-sqlalchemy.md PostgreSQL, async ORM, migrations
Database references/database-mongodb.md MongoDB with Beanie/Motor
Caching references/caching-redis.md Redis caching, sessions, pub/sub
Security references/security-auth.md OAuth2, JWT, OIDC, RBAC
Security references/security-owasp.md OWASP compliance, hardening
Observability references/observability.md Logging, metrics, tracing
Microservices references/microservices.md Celery, Kafka, event-driven
API Design references/api-lifecycle.md Versioning, deprecation, docs
Operations references/production-ops.md Health checks, K8s, deployment

Core Tenets

1. Thin Routes, Fat Services

Routes handle HTTP concerns only. Business logic lives in services.

# WRONG: Logic in route
@router.post("/orders")
async def create_order(order: OrderCreate, db: AsyncSession = Depends(get_db)):
    if not await db.get(Product, order.product_id):
        raise HTTPException(404, "Product not found")
    # ... 50 more lines of business logic
    return order

# RIGHT: Thin route, fat service
@router.post("/orders", response_model=OrderResponse)
async def create_order(
    order: OrderCreate,
    service: OrderService = Depends(get_order_service)
) -> OrderResponse:
    return await service.create(order)

Read the full file on GitHub · 437 lines

Changes

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.

  1. 5d ago First seen · 437 lines · 39 tokens per session scan A d80806080323

Subscribe to this mod's changes

fastapi-senior-dev is a skill published in the GitHub repository hackermanishackerman/claude-skills-vault (2 stars, last pushed yesterday), licensed MIT. It adds 39 tokens to every session and 2,999 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It is 100% identical to fastapi-senior-dev, differing in 0 lines, and is treated as a copy.