fastapi-run

fastapi-run is a skill for Claude Code from steph-dove/klaussy-agents. It costs 64 tokens per session (986 once invoked), scanned A, original, MIT.

A guide for starting this project's application and exercising a real user flow locally.

In plain words
What is it for?
It helps run a server, command-line tool, or other application, then perform enough actions to observe the requested behavior and smoke-test a change.
Why use it?
It avoids treating a successful process start as proof that the application works. It checks the project's documented setup, required configuration, and the behavior the user cares about.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: mentions CLAUDE.md; installed under .agents/ (shared by several agents).

Part of the klaussy plugin — 79 skills, 3 hooks, 1 MCP server shipped together

Good fit It helps run a server, command-line tool, or other application, then perform enough actions to observe the requested behavior and smoke-test a change.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/steph-dove/klaussy-agents/fastapi-run
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 steph-dove/klaussy-agents --skill fastapi-run
Clone the repo
git clone --depth 1 https://github.com/steph-dove/klaussy-agents

Made for: Claude Code.

Or install klaussy, the plugin that ships this one along with the rest of its 79 skills, 3 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-run

README.md
[![agentmods](https://agentmods.dev/badge/skills/steph-dove/klaussy-agents/fastapi-run/github.svg)](https://agentmods.dev/skills/steph-dove/klaussy-agents/fastapi-run)
Your own site
<a href="https://agentmods.dev/skills/steph-dove/klaussy-agents/fastapi-run"><img src="https://agentmods.dev/badge/skills/steph-dove/klaussy-agents/fastapi-run/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-run

Your own site · 80×15
<a href="https://agentmods.dev/skills/steph-dove/klaussy-agents/fastapi-run"><img src="https://agentmods.dev/badge/skills/steph-dove/klaussy-agents/fastapi-run.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 64 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 986 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 $0.00064 $0.00986
Opus 5 $0.00032 $0.00493
Sonnet 5 $0.00013 $0.00197
Haiku 4.5 $0.00006 $0.00099

Measured 11d ago against content hash 3e94029f2321, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

fastapi-run 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 11d 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.

Origin

Copies of this mod

2 near-identical copies found in the catalogue:

examples/fastapi/.agents/skills/fastapi-run/SKILL.md · 41 lines

How it starts

The opening of the file, as written. The whole thing — 41 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Run this project's app and drive it far enough to observe the behavior the user cares about. Don't just start it and call it done — exercise the actual flow.

Steps

  1. Find the run command in CLAUDE.md. Read CLAUDE.md — its Commands section is the source of truth for how this project installs, builds, and runs. Look for entries labeled run / start / serve / dev, a CLI entrypoint, or a server command (this project may expose more than one, e.g. a CLI and a server — pick the one that matches what the user asked for; if it's ambiguous, ask).
  2. Read any .claude/rules/*.md whose paths: glob covers the code you're about to exercise — it may note required env vars, ports, or setup the command alone doesn't reveal.
  3. Fall back to the stack only if CLAUDE.md names no run command (see the defaults below).
  4. Prepare the environment. Install/build first only if needed (a fresh checkout, or the run command errors on missing deps) — e.g. the editable install or npm install from CLAUDE.md. If the app needs an env var, config file, or secret that isn't present, STOP and ask rather than inventing a value — a guessed secret produces a misleading failure.
  5. Run it, matched to the app's shape:
    • One-shot (CLI, script, build): invoke it directly. Start with a cheap sanity call (--help / --version) to confirm it launches, then run a representative real command — the one that exercises the change or the behavior in question.
    • Long-running (web server, watcher, MCP/daemon): start it in the background, wait for its ready signal (a "listening on…" line, a health endpoint), then drive it from a second command — hit the endpoint, send a request, run the client. Tear it down when you're done; don't leave a stray process running.
  6. Observe and report. Capture the actual output — the CLI result, the HTTP response, the rendered page, the log line. State plainly what you saw and whether it matches the expected behavior. If it failed, show the real error; don't paper over it.

Read the full file on GitHub · 41 lines

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. 11d ago First seen · 41 lines · 64 tokens per session scan A 3e94029f2321

Subscribe to this mod's changes

fastapi-run is a skill published in the GitHub repository steph-dove/klaussy-agents (16 stars, last pushed 14d ago), licensed MIT. It adds 64 tokens to every session and 986 once invoked, about $0.0003 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 2026-08-30.