fastmcp

fastmcp is a skill for Claude Code, Codex from braxtonROSE4/zorro-agent. It costs 62 tokens per session (1,942 once invoked), scanned A, a copy of fastmcp, MIT.

A Python toolkit for building MCP servers, which let AI agents use tools, data sources, or prompts. It also covers checking, installing, and deploying those servers.

In plain words
What is it for?
Creating and testing MCP servers, exposing tools or resources, connecting them to clients such as Claude Code or Cursor, and preparing HTTP deployments.
Why use it?
It provides a defined workflow for turning an API, database, command-line tool, or file-processing task into something an AI client can use.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions Claude Code.

Good fit Creating and testing MCP servers, exposing tools or resources, connecting them to clients such as Claude Code or Cursor, and preparing HTTP deployments.

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Install with agentmods
npx agentmods add skills/braxtonrose4/zorro-agent/fastmcp
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 braxtonROSE4/zorro-agent --skill fastmcp
Clone the repo
git clone --depth 1 https://github.com/braxtonROSE4/zorro-agent

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 fastmcp

README.md
[![agentmods](https://agentmods.dev/badge/skills/braxtonrose4/zorro-agent/fastmcp/github.svg)](https://agentmods.dev/skills/braxtonrose4/zorro-agent/fastmcp)
Your own site
<a href="https://agentmods.dev/skills/braxtonrose4/zorro-agent/fastmcp"><img src="https://agentmods.dev/badge/skills/braxtonrose4/zorro-agent/fastmcp/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 fastmcp

Your own site · 80×15
<a href="https://agentmods.dev/skills/braxtonrose4/zorro-agent/fastmcp"><img src="https://agentmods.dev/badge/skills/braxtonrose4/zorro-agent/fastmcp.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 62 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,942 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 86% copy Near-identical to another mod 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 $0.00062 $0.01942
Opus 5 $0.00031 $0.00971
Sonnet 5 $0.00012 $0.00388
Haiku 4.5 $0.00006 $0.00194

Measured 9d ago against content hash d51a4f990472, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

fastmcp 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.

The scan reads SKILL.md. This mod also ships 4 executable files (scripts/scaffold_fastmcp.py, templates/api_wrapper.py, templates/database_server.py, …), 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.

Origin

This is a copy

86% identical to fastmcp — 27 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

optional-skills/mcp/fastmcp/SKILL.md · 300 lines

How it starts

The opening of the file, as written. The whole thing — 300 lines — stays where its author put it; the contents beside it link to each section on GitHub.

FastMCP

Build MCP servers in Python with FastMCP, validate them locally, install them into MCP clients, and deploy them as HTTP endpoints.

When to Use

Use this skill when the task is to:

  • create a new MCP server in Python
  • wrap an API, database, CLI, or file-processing workflow as MCP tools
  • expose resources or prompts in addition to tools
  • smoke-test a server with the FastMCP CLI before wiring it into Zorro or another client
  • install a server into Claude Code, Claude Desktop, Cursor, or a similar MCP client
  • prepare a FastMCP server repo for HTTP deployment

Use native-mcp when the server already exists and only needs to be connected to Zorro. Use mcporter when the goal is ad-hoc CLI access to an existing MCP server instead of building one.

Prerequisites

Install FastMCP in the working environment first:

pip install fastmcp
fastmcp version

For the API template, install httpx if it is not already present:

pip install httpx

Included Files

Templates

  • templates/api_wrapper.py - REST API wrapper with auth header support
  • templates/database_server.py - read-only SQLite query server
  • templates/file_processor.py - text-file inspection and search server

Scripts

  • scripts/scaffold_fastmcp.py - copy a starter template and replace the server name placeholder

References

  • references/fastmcp-cli.md - FastMCP CLI workflow, installation targets, and deployment checks

Workflow

1. Pick the Smallest Viable Server Shape

Choose the narrowest useful surface area first:

  • API wrapper: start with 1-3 high-value endpoints, not the whole API
  • database server: expose read-only introspection and a constrained query path
  • file processor: expose deterministic operations with explicit path arguments
  • prompts/resources: add only when the client needs reusable prompt templates or discoverable documents

Prefer a thin server with good names, docstrings, and schemas over a large server with vague tools.

Read the full file on GitHub · 300 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. 9d ago First seen · 300 lines · 62 tokens per session scan A d51a4f990472

Subscribe to this mod's changes

fastmcp is a skill published in the GitHub repository braxtonROSE4/zorro-agent (8 stars, last pushed 4mo ago), licensed MIT. It adds 62 tokens to every session and 1,942 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to fastmcp, differing in 27 lines, and is treated as a copy.

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