Borrowing it
Nothing to install: this file belongs to shirin292006/mcp-toolkit. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/shirin292006/mcp-toolkit/main/CLAUDE.mdgit clone --depth 1 https://github.com/shirin292006/mcp-toolkitWrote 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.
[](https://agentmods.dev/instructions/shirin292006/mcp-toolkit/claude-md)<a href="https://agentmods.dev/instructions/shirin292006/mcp-toolkit/claude-md"><img src="https://agentmods.dev/badge/instructions/shirin292006/mcp-toolkit/claude-md/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.
<a href="https://agentmods.dev/instructions/shirin292006/mcp-toolkit/claude-md"><img src="https://agentmods.dev/badge/instructions/shirin292006/mcp-toolkit/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.04169 | $0.04169 |
| Opus 5.5 | $0.01668 | $0.01668 |
| Sonnet 5.5 | $0.00834 | $0.00834 |
| Haiku 4.5 | $0.00417 | $0.00417 |
Grade A, and why
mcp-toolkit CLAUDE.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 2mo 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.
This is a copy
94% identical to fastmcp CLAUDE.md — 188 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.
How it starts
The opening of the file, as written. The whole thing — 187 lines — stays where its author put it; the contents beside it link to each section on GitHub.
FastMCP Development Guidelines
Audience: LLM-driven engineering agents and human developers
Note:
AGENTS.mdis a symlink to this file. EditCLAUDE.mddirectly.
FastMCP is a comprehensive Python framework (Python ≥3.10) for building Model Context Protocol (MCP) servers and clients. This is the actively maintained v2.0 providing a complete toolkit for the MCP ecosystem.
Required Development Workflow
CRITICAL: Always run these commands in sequence before committing.
uv sync # Install dependencies
uv run pytest -n auto # Run full test suite
In addition, you must pass static checks. This is generally done as a pre-commit hook with prek but you can run it manually with:
uv run prek run --all-files # Ruff + Prettier + ty
Tests must pass and lint/typing must be clean before committing.
Repository Structure
| Path | Purpose |
|---|---|
fastmcp_slim/fastmcp/ |
Library source code |
├─server/ |
Server implementation |
│ ├─auth/ |
Authentication providers |
│ └─middleware/ |
Error handling, logging, rate limiting |
├─client/ |
Client SDK |
│ └─auth/ |
Client authentication |
├─tools/ |
Tool definitions |
├─resources/ |
Resources and resource templates |
├─prompts/ |
Prompt templates |
├─cli/ |
CLI commands |
└─utilities/ |
Shared utilities |
tests/ |
Pytest suite |
docs/ |
Mintlify docs (gofastmcp.com) |
Core MCP Objects
When modifying MCP functionality, changes typically need to be applied across all object types:
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.
- 2mo ago First seen · 187 lines · 4,169 tokens per session scan A 5d017f8d1bbd
mcp-toolkit CLAUDE.md is an instructions file published in the GitHub repository shirin292006/mcp-toolkit (0 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 4,169 tokens to every session, about $0.0167 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 94% identical to fastmcp CLAUDE.md, differing in 188 lines, and is treated as a copy.
mcp-toolkit CLAUDE.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| mcp-toolkit CLAUDE.mdshirin292006/mcp-toolkit | Instructions file | 0 | 3mo ago | Apache-2.0 | A | 4,169 | Claude Code |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | today | MIT | A | 7,461 | Codex, OpenCode |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | yesterday | MIT | A | 4,680 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |