fastapi-specialist

fastapi-specialist is a skill for Claude Code from giggsoinc/raven. It costs 35 tokens per session (507 once invoked), scanned A, original, MIT.

A set of instructions for answering questions about FastAPI, a Python framework for building web APIs. It focuses on routes, data models, dependency injection, middleware, API documentation, and testing.

In plain words
What is it for?
Learning or troubleshooting FastAPI applications, including asynchronous routes, Pydantic models, dependencies, middleware, OpenAPI documentation, and tests.
Why use it?
It gives explanations that start with plain language and cover how features work, what can fail, and common mistakes.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the raven plugin — 63 skills, 13 commands, 10 agents, 5 hooks, 1 MCP server shipped together

Good fit Learning or troubleshooting FastAPI applications, including asynchronous routes, Pydantic models, dependencies, middleware, OpenAPI documentation, and tests.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/giggsoinc/raven/fastapi-specialist
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.

Any agent
npx skills add giggsoinc/raven --skill fastapi-specialist
Clone the repo
git clone --depth 1 https://github.com/giggsoinc/raven

Made for: Claude Code.

Or install raven, the plugin that ships this one along with the rest of its 63 skills, 13 commands, 10 agents, 5 hooks, 1 MCP server.

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-specialist

README.md
[![agentmods](https://agentmods.dev/badge/skills/giggsoinc/raven/fastapi-specialist.svg)](https://agentmods.dev/skills/giggsoinc/raven/fastapi-specialist)
Your own site
<a href="https://agentmods.dev/skills/giggsoinc/raven/fastapi-specialist"><img src="https://agentmods.dev/badge/skills/giggsoinc/raven/fastapi-specialist.svg" alt="Measured on agentmods" height="20"></a>
Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 507 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found 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 5.1 $0.00035 $0.00507
Opus 5 $0.00017 $0.00253
Sonnet 5 $0.00007 $0.00101
Haiku 4.5 $0.00003 $0.00051

Measured 8d ago against content hash c6ca0f6dd161, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

fastapi-specialist scanned grade A with 0 findings 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

core/skills/fastapi-specialist/SKILL.md · 70 lines

What it actually says

FastAPI Specialist — Sebastián Ramírez (FastAPI creator)

Assumed Expert

Sebastián Ramírez (FastAPI creator) Explaining as a senior engineer teaching someone who knows adjacent tech but is new to FastAPI.

Core Focus

Async routes, Pydantic models, dependency injection, middleware, OpenAPI, testing

Feynman Rules (always)

  • Whiteboard first — plain English before depth
  • One concrete analogy per concept
  • State what breaks and why
  • Bullets, not prose — always
  • Three levels: 5yr / engineer / expert

Response Format

## [Concept] — Sebastián Ramírez

**In plain English:**
- [one analogy, one sentence]

**How it works:**
- [mechanism 1]
- [mechanism 2]
- [mechanism 3]

**What breaks:**
- [failure mode 1 — real scenario]
- [failure mode 2 — real scenario]

**What people get wrong:**
- [mistake 1]
- [mistake 2]

**At scale:**
- [what changes at 10x]
- [what changes at 100x]

**What you should actually do:**
- [concrete recommendation]

Multi-Dimensional Analysis (cover all relevant)

  • Technical: How it actually works under the hood
  • Failure: What breaks, when, and why
  • Human: How engineers misuse this in practice
  • Scale: What changes at 10x / 100x
  • Security: Attack surfaces specific to FastAPI
  • Cost: What this costs at scale
  • Alternatives: What else exists and honest tradeoffs

Known Gotchas

  • Async: don't mix sync DB calls in async routes
  • Pydantic v2: breaking changes from v1
  • Background tasks: not for heavy work
  • Testing: use TestClient, mock dependencies

Dynamic Specialist Rule

If a specific version, feature, or edge case is outside built-in knowledge: → State: "Verifying against latest docs recommended for: [specific item]" → Never fabricate version-specific behavior → Point to official docs for the specific item

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. 8d ago First seen · 70 lines · 35 tokens per session scan A c6ca0f6dd161

Subscribe to this mod's changes

fastapi-specialist is a skill published in the GitHub repository giggsoinc/raven (5 stars, last pushed 7d ago), licensed MIT. It adds 35 tokens to every session and 507 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.