Borrowing it
Nothing to install: this file belongs to henrychong-ai/yggdrasil-mcp. 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/henrychong-ai/yggdrasil-mcp/main/CLAUDE.mdgit clone --depth 1 https://github.com/henrychong-ai/yggdrasil-mcpWrote 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/henrychong-ai/yggdrasil-mcp/claude-md)<a href="https://agentmods.dev/instructions/henrychong-ai/yggdrasil-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/henrychong-ai/yggdrasil-mcp/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/henrychong-ai/yggdrasil-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/henrychong-ai/yggdrasil-mcp/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 | $0.05952 | $0.05952 |
| Opus 5 | $0.02976 | $0.02976 |
| Sonnet 5 | $0.01190 | $0.01190 |
| Haiku 4.5 | $0.00595 | $0.00595 |
Grade A, and why
yggdrasil-mcp CLAUDE.md scanned grade A with 1 finding 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 10d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl -s "https://raw.githubusercontent.com/modelcontextprotocol/servers/main/src/sequentialthinking/index.ts" -o /tmp/upstream-st.ts How it starts
The opening of the file, as written. The whole thing — 502 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
Project Overview
Yggdrasil-MCP is a reasoning orchestration MCP server implementing Tree of Thoughts with multi-agent evaluation. It's a fork of Anthropic's @modelcontextprotocol/server-sequential-thinking with critical bug fixes and an enhanced feature roadmap. Current version: see package.json / CHANGELOG.md (v1.2.0 added Claude Desktop Extension .mcpb distribution).
| Aspect | Details |
|---|---|
| Package | yggdrasil-mcp |
| npm | https://www.npmjs.com/package/yggdrasil-mcp |
| Origin | Fork of @modelcontextprotocol/server-sequential-thinking |
| Upstream | https://github.com/modelcontextprotocol/servers/tree/main/src/sequentialthinking |
| Key Fix | Claude Code string coercion bug #3084 |
| Tools | sequential_thinking, deep_planning, list_plans, get_plan, promote_plan, archive_plans |
| Distribution | npm (npx -y yggdrasil-mcp) for Claude Code; .mcpb via packages.henrychong.com/yggdrasil-mcp/ for Claude Desktop |
Tech Stack
| Layer | Technology |
|---|---|
| Language | TypeScript |
| Runtime | Node.js 24 |
| MCP SDK | @modelcontextprotocol/sdk |
| Validation | Zod |
| Testing | Vitest + @vitest/coverage-v8 |
| Linting | Oxlint (Rust-based, 668 built-in rules) |
| Formatting | Biome (linter disabled, Prettier-compatible) |
| Git Hooks | Husky + lint-staged |
| Package Manager | pnpm |
| CI/CD | GitHub Actions (npm publish on v* tags) |
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.
- 10d ago First seen · 502 lines · 5,952 tokens per session scan A eb647f8576fb
yggdrasil-mcp CLAUDE.md is an instructions file published in the GitHub repository henrychong-ai/yggdrasil-mcp (3 stars, last pushed today), licensed MIT. It adds 5,952 tokens to every session, about $0.0298 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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