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 agentmods add skills/vikasudasi/skill-vault/fastapi-rest-apinpx skills add vikasudasi/skill-vault --skill fastapi-rest-apigit clone --depth 1 https://github.com/vikasudasi/skill-vaultWrote 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/vikasudasi/skill-vault/fastapi-rest-api)<a href="https://agentmods.dev/skills/vikasudasi/skill-vault/fastapi-rest-api"><img src="https://agentmods.dev/badge/skills/vikasudasi/skill-vault/fastapi-rest-api.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 | $0.00028 | $0.00412 |
| Opus 5 | $0.00014 | $0.00206 |
| Sonnet 5 | $0.00006 | $0.00082 |
| Haiku 4.5 | $0.00003 | $0.00041 |
Grade A, and why
fastapi-rest-api 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 3d 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.
What it actually says
Building a FastAPI REST API
Use when exposing an HTTP API: resources, validation, OpenAPI docs, and clean error responses.
Structure
app/
main.py # FastAPI() + include_router
routers/
skills.py # APIRouter
schemas.py # Pydantic request/response models
from fastapi import APIRouter
router = APIRouter(prefix="/skills", tags=["skills"])
@router.get("/{skill_id}")
def get_skill(skill_id: str) -> dict: ...
Dependency injection
Resolve auth/db via Depends so handlers stay thin and testable:
def get_db():
yield conn
@router.get("/{id}")
def read(db=Depends(get_db)): ...
Error handling
Raise HTTPException(status_code=404, detail="..."), or map domain exceptions
to status codes in a small handler so handlers never leak internals.
Testing
from fastapi.testclient import TestClient
def test_create():
client = TestClient(app)
r = client.post("/skills", json={...})
assert r.status_code == 201
Pitfalls
- Declare response models to get typed OpenAPI and docs.
- Use
Dependsfor shared setup instead of globals — it enables override in tests. - Don't put business logic in routers; keep them as thin transport layer.
What ships with it
2 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.
- 3d ago First seen · 73 lines · 28 tokens per session scan A 5d1be310af6c
fastapi-rest-api is a skill published in the GitHub repository vikasudasi/skill-vault (0 stars, last pushed 18d ago), licensed Apache-2.0. It adds 28 tokens to every session and 412 once invoked, about $0.0001 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.
Other skills, from other repositories
fastapi-patterns
FastAPI production patterns — routing, dependency injection, background tasks, streaming, error handling, and async. Use when building or reviewing a FastAPI service.
fastapi-expert
Expert-level FastAPI development for high-performance Python APIs with async support.
fastapi-best-practices
Use this skill when creating or modifying Python backend services with FastAPI. It defines API design, security, and testing standards.
fastapi-guard
Production-ready security middleware for FastAPI. Use when adding IP filtering, rate limiting, per-route security decorators, route-resolution strict mode, global behavior rules, passive/log-only mode, or Guard Agent SaaS telemetry to a FastAPI app. Covers SecurityMiddleware setup, SecurityConfig tuning, and the…
fastapi
FastAPI best practices + Pydantic. Use when building or reviewing FastAPI APIs.
fastapi-docs
FastAPI 0.115+ — path/query params, Pydantic, dependency injection, OAuth2/JWT, middleware, WebSocket, testing.