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 aj-geddes/useful-ai-prompts --skill fastapi-developmentgit clone --depth 1 https://github.com/aj-geddes/useful-ai-promptsWrote 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/aj-geddes/useful-ai-prompts/fastapi-development)<a href="https://agentmods.dev/skills/aj-geddes/useful-ai-prompts/fastapi-development"><img src="https://agentmods.dev/badge/skills/aj-geddes/useful-ai-prompts/fastapi-development/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/aj-geddes/useful-ai-prompts/fastapi-development"><img src="https://agentmods.dev/badge/skills/aj-geddes/useful-ai-prompts/fastapi-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
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 | $0.00046 | $0.00716 |
| Opus 5 | $0.00023 | $0.00358 |
| Sonnet 5 | $0.00009 | $0.00143 |
| Haiku 4.5 | $0.00005 | $0.00072 |
Grade A, and why
fastapi-development 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 9d 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.
How it starts
The opening of the file, as written. The whole thing — 105 lines — stays where its author put it; the contents beside it link to each section on GitHub.
FastAPI Development
Table of Contents
Overview
Create fast, modern Python APIs using FastAPI with async/await support, automatic API documentation, type validation using Pydantic, dependency injection, JWT authentication, and SQLAlchemy ORM integration.
When to Use
- Building high-performance Python REST APIs
- Creating async API endpoints
- Implementing automatic OpenAPI/Swagger documentation
- Leveraging Python type hints for validation
- Building microservices with async support
- Integrating Pydantic for data validation
Quick Start
Minimal working example:
# main.py
from fastapi import FastAPI, HTTPException, status
from fastapi.middleware.cors import CORSMiddleware
from contextlib import asynccontextmanager
import logging
# Setup logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)
# Create FastAPI instance
app = FastAPI(
title="API Service",
description="A modern FastAPI application",
version="1.0.0",
docs_url="/api/docs",
openapi_url="/api/openapi.json"
)
# Add CORS middleware
app.add_middleware(
CORSMiddleware,
allow_origins=["http://localhost:3000"],
allow_credentials=True,
allow_methods=["*"],
// ... (see reference guides for full implementation)
Reference Guides
Detailed implementations in the references/ directory:
| Guide | Contents |
|---|---|
| FastAPI Application Setup | FastAPI Application Setup |
| Pydantic Models for Validation | Pydantic Models for Validation |
| Async Database Models and Queries | Async Database Models and Queries |
| Security and JWT Authentication | Security and JWT Authentication |
| Service Layer for Business Logic | Service Layer for Business Logic |
| API Routes with Async Endpoints | API Routes with Async Endpoints |
What ships with it
8 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.
- references/api-routes-with-async-endpoints.md 2.7 KB
- references/async-database-models-and-queries.md 2.0 KB
- references/fastapi-application-setup.md 1.3 KB
- references/pydantic-models-for-validation.md 2.0 KB
- references/security-and-jwt-authentication.md 1.6 KB
- references/service-layer-for-business-logic.md 2.9 KB
- scripts/validate-api.sh 440 B runs code
- templates/api-scaffold.yaml 467 B
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.
- 9d ago First seen · 105 lines · 46 tokens per session scan A 457d44d0eda3
fastapi-development is a skill published in the GitHub repository aj-geddes/useful-ai-prompts (338 stars, last pushed 6mo ago), licensed MIT. It adds 46 tokens to every session and 716 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 2026-09-03.
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