fastapi

fastapi is a skill for Claude Code, Codex from fmind/dot. It costs 32 tokens per session (338 once invoked), scanned A, original, MIT.

A guide for building and maintaining FastAPI services, which are Python web applications that receive requests and return data. It covers routes, input handling, shared dependencies, streaming responses, and the generated API description.

In plain words
What is it for?
Use it to add or change web routes, validate requests, manage dependencies, stream responses, and test the service and its OpenAPI schema.
Why use it?
It keeps changes consistent with the existing service and its installed FastAPI version. Request and lifecycle tests help reveal broken behavior or changes to the public API.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to add or change web routes, validate requests, manage dependencies, stream responses, and test the service and its OpenAPI schema.

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Install with agentmods
npx agentmods add skills/fmind/dot/fastapi
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 fmind/dot --skill fastapi
Clone the repo
git clone --depth 1 https://github.com/fmind/dot

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

README.md
[![agentmods](https://agentmods.dev/badge/skills/fmind/dot/fastapi/github.svg)](https://agentmods.dev/skills/fmind/dot/fastapi)
Your own site
<a href="https://agentmods.dev/skills/fmind/dot/fastapi"><img src="https://agentmods.dev/badge/skills/fmind/dot/fastapi/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

Your own site · 80×15
<a href="https://agentmods.dev/skills/fmind/dot/fastapi"><img src="https://agentmods.dev/badge/skills/fmind/dot/fastapi.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 338 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 $0.00032 $0.00338
Opus 5 $0.00016 $0.00169
Sonnet 5 $0.00006 $0.00068
Haiku 4.5 $0.00003 $0.00034

Measured yesterday against content hash 4a593923d946, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

fastapi 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 yesterday.

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.

skills/fastapi/SKILL.md · 33 lines

What it actually says

FastAPI

Use this for an existing or explicitly chosen FastAPI service, including an agents-cli scaffold; litestar remains the default for new ordinary web apps.

Workflow

  1. Inspect the installed FastAPI version and generated project contract before changing the app or dependencies.
  2. Choose the official framework guidance, then adapt routes, validation, dependency lifetimes, or streaming to the existing application.
  3. Run local request and lifespan tests and inspect the OpenAPI output when the public schema changes.

Gotchas

  • The skill is shipped within the framework source package and is discovered by the skills CLI. Installing the Python package alone does not establish host discovery.
  • Do not convert an agents-cli FastAPI scaffold to Litestar while implementing an agent feature.

Official Skills

Upstream: fastapi/fastapi. Follow the shared vendor-skill policy and select the FastAPI application guidance.

Documentation

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. yesterday First seen · 33 lines · 32 tokens per session scan A 4a593923d946

Subscribe to this mod's changes

fastapi is a skill published in the GitHub repository fmind/dot (4 stars, last pushed yesterday), licensed MIT. It adds 32 tokens to every session and 338 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 2026-09-07.