fastapi-docs-mcp AGENTS.md

A read-only MCP server that finds and returns FastAPI documentation. FastAPI is a Python framework for building web APIs; MCP lets an agent call the server's documentation tools.

In plain words
What is it for?
Fetching a named FastAPI documentation page or searching the documentation by topic, with related page paths.
Why use it?
It lets an agent look up the relevant official documentation without changing files or running code on the computer.

Instructions file for CodexOpenCode

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.

agentmods
npx agentmods add instructions/jaredthivener/fastapi-docs-mcp/agents-md
Clone the repo
git clone --depth 1 https://github.com/jaredthivener/fastapi-docs-mcp

Made for: Codex, OpenCode.

Per session 2,017 This file is loaded in full into every session.
When invoked 2,017 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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 $0.02017 $0.02017
Opus 5 $0.01009 $0.01009
Sonnet 5 $0.00403 $0.00403
Haiku 4.5 $0.00202 $0.00202

Measured 2d ago against content hash b402787cb831, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

fastapi-docs-mcp AGENTS.md 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 2d 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.

AGENTS.md · 181 lines

How it starts

The opening of the file, as written. The whole thing — 181 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md — FastAPI Docs MCP Server

Agent configuration reference for clients connecting to this MCP server.


Server identity

Property Value
Server name FastAPI-Docs-Expert
Protocol MCP over stdio (transport: stdio)
Runtime FastMCP ≥ 3.4.2
Entrypoint python main.py

Tools

All six tools are read-only (readOnlyHint: true, openWorldHint: true). None write files, mutate state, or execute code on the host.

get_fastapi_docs(path: str) → str

Fetch the full content of a single FastAPI doc page by its path slug.

  • When to use: the user names a specific topic, tutorial, or advanced page.
  • Input: path slug, e.g. "tutorial/first-steps", "advanced/websockets" (no leading slash, no trailing slash).
  • Output: cleaned markdown with prose, Python code blocks, and the canonical URL.
  • Token cost (tiktoken est.): ~2,490 output tokens for a typical page.

search_fastapi_docs(query: str) → str

Keyword search across all sitemap URLs; returns the best-matching page's content plus up to 4 related paths.

  • When to use: the user asks about a topic without naming an exact page; always try this before get_fastapi_docs.
  • Input: plain search term, e.g. "cors", "database", "websocket". Aliases like "auth" are resolved server-side.
  • Output: best-match page content + related-page list.
  • Token cost (tiktoken est.): ~1,221 output tokens.

list_fastapi_pages() → str

List every page in the FastAPI sitemap, categorized by section (Tutorial, Advanced, Deployment, How-To, Reference).

  • When to use: the user wants to browse, or when search_fastapi_docs returns no results.
  • Input: none.
  • Output: section-grouped bullet list with total page count.
  • Token cost (tiktoken est.): ~844 output tokens.

get_fastapi_example(topic: str) → str

Return Python code blocks only (no prose) for a topic — up to 5 examples from the best-matching page.

  • When to use: the user explicitly asks for code or an example, not an explanation.
  • Input: topic slug, e.g. "cors", "jwt", "websockets".
  • Output: fenced python blocks, source URL, example count.
  • Token cost (tiktoken est.): ~147 output tokens.

Read the full file on GitHub · 181 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. 2d ago First seen · 181 lines · 2,017 tokens per session scan A b402787cb831

Subscribe to this mod's changes

fastapi-docs-mcp AGENTS.md is an instructions file published in the GitHub repository jaredthivener/fastapi-docs-mcp (3 stars, last pushed 8d ago), licensed MIT. It adds 2,017 tokens to every session, about $0.0101 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.

Related

Other instructions, from other repositories

spec-kit AGENTS.md

AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.

github/spec-kit · 7,104 tokens

vscode buildNext.instructions.md

Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).

microsoft/vscode · 6,785 tokens

codex AGENTS.md

AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.

openai/codex · 5,182 tokens

langchain AGENTS.md

AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.

langchain-ai/langchain · 4,345 tokens

vscode oss-third-party-notices.instructions.md

Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).

microsoft/vscode · 5,001 tokens

next.js AGENTS.md

Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.

vercel/next.js · 7,296 tokens