fastapi-app

fastapi-app is a skill for Claude Code from ccplugins/awesome-claude-code-plugins. It costs 103 tokens per session (1,071 once invoked), scanned A, original, Apache-2.0.

A starter workflow for creating a FastAPI backend, a Python service that provides web API endpoints. It sets up asynchronous database access, migrations, data validation, layered code structure, and JWT login support.

In plain words
What is it for?
Scaffolding a new FastAPI service, Python REST API, or asynchronous backend with SQLAlchemy, PostgreSQL access, Alembic migrations, Pydantic settings, and JWT authentication.
Why use it?
It provides a defined starting structure and requires the project brief and configuration choices before generating the service.

Skill for Claude Code

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

Part of the app-starter plugin — 3 skills shipped together

Good fit Scaffolding a new FastAPI service, Python REST API, or asynchronous backend with SQLAlchemy, PostgreSQL access, Alembic migrations, Pydantic settings, and JWT authentication.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ccplugins/awesome-claude-code-plugins/fastapi-app
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 ccplugins/awesome-claude-code-plugins --skill fastapi-app
Clone the repo
git clone --depth 1 https://github.com/ccplugins/awesome-claude-code-plugins

Made for: Claude Code.

Or install app-starter, the plugin that ships this one along with the rest of its 3 skills.

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-app

README.md
[![agentmods](https://agentmods.dev/badge/skills/ccplugins/awesome-claude-code-plugins/fastapi-app/github.svg)](https://agentmods.dev/skills/ccplugins/awesome-claude-code-plugins/fastapi-app)
Your own site
<a href="https://agentmods.dev/skills/ccplugins/awesome-claude-code-plugins/fastapi-app"><img src="https://agentmods.dev/badge/skills/ccplugins/awesome-claude-code-plugins/fastapi-app/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.

agentmods 80×15 button for fastapi-app

Your own site · 80×15
<a href="https://agentmods.dev/skills/ccplugins/awesome-claude-code-plugins/fastapi-app"><img src="https://agentmods.dev/badge/skills/ccplugins/awesome-claude-code-plugins/fastapi-app.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 103 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,071 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00103 $0.01071
Opus 5.5 $0.00041 $0.00428
Sonnet 5.5 $0.00021 $0.00214
Haiku 4.5 $0.00010 $0.00107

Measured 1mo ago against content hash d4ae59e8dace, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

fastapi-app 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 1mo ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/check-latest.sh), 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.

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.

plugins/app-starter/skills/fastapi-app/SKILL.md · 88 lines

How it starts

The opening of the file, as written. The whole thing — 88 lines — stays where its author put it; the contents beside it link to each section on GitHub.

fastapi-app

Bootstrap a new FastAPI backend the way this owner builds them: async SQLAlchemy 2.0 with asyncpg, Alembic migrations, Pydantic v2 settings, a layered structure (routers, services, models, schemas), JWT auth, and the house git and CI workflow. Deployable to a container or Vercel.

First read the shared rules (they override anything you remember): ../shared/house-rules.md, ../shared/no-ai-attribution.md, ../shared/git-and-ci.md, ../shared/docs-and-context.md, ../shared/hardening.md, and (for public repos) ../shared/open-source-docs.md.

Step 0. Get the brief, then ask the variant questions (hard stop)

This is a hard stop. Do not run any scaffolding command until the user has answered.

First, get the project brief: one paragraph on what the service does, its main resources and endpoints, who calls it, and any hard constraints. If the user has not given one, ask for it. The brief drives naming, the domain modules, and the data model.

Then ask the variant questions. If a choice has multiple options, ask; do not assume. Ask in one batch, then proceed.

  1. Repo visibility: private, open-source, or private-plus-open-source.
  2. Auth: JWT (python-jose or PyJWT), OAuth (Google), API-key, or none yet.
  3. Database: Postgres via async SQLAlchemy + asyncpg (default), or none yet.
  4. Dependency tooling: uv (default, fast) or pip + requirements.txt.
  5. Admin UI: SQLAdmin, or none.
  6. Deploy target: Docker container (default) or Vercel serverless.

If the user already answered some, do not re-ask.

Step 1. Verify environment and current versions

  • Check Python (python3 --version, want a current supported 3.x).
  • Run scripts/check-latest.sh for current stable versions from PyPI. Pin those, not versions from memory (../shared/house-rules.md rule 2).
  • Pull current FastAPI, SQLAlchemy 2.0, and Pydantic v2 docs via Context7 before writing code (../shared/docs-and-context.md). SQLAlchemy 2.0 async and Pydantic v2 both broke v1 patterns; do not write v1-era code from memory.

Read the full file on GitHub · 88 lines

Files

What ships with it

5 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.

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. 1mo ago First seen · 88 lines · 103 tokens per session scan A d4ae59e8dace

Subscribe to this mod's changes

fastapi-app is a skill published in the GitHub repository ccplugins/awesome-claude-code-plugins (974 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 103 tokens to every session and 1,071 once invoked, about $0.0004 per session on Opus 5.5. 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 2026-08-30.

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