Borrowing it
Nothing to install: this file belongs to avivsinai/langfuse-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/avivsinai/langfuse-mcp/main/CLAUDE.mdgit clone --depth 1 https://github.com/avivsinai/langfuse-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/avivsinai/langfuse-mcp/claude-md)<a href="https://agentmods.dev/instructions/avivsinai/langfuse-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/avivsinai/langfuse-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/avivsinai/langfuse-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/avivsinai/langfuse-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 | $0.00813 | $0.00813 |
| Opus 5 | $0.00407 | $0.00407 |
| Sonnet 5 | $0.00163 | $0.00163 |
| Haiku 4.5 | $0.00081 | $0.00081 |
Grade A, and why
langfuse-mcp 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 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.
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.
How it starts
The opening of the file, as written. The whole thing — 62 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Claude Code Instructions
This is the master agent instruction file for this repository. Keep repository policy here. AGENTS.md exists only as a Codex compatibility shim and should contain only Codex-specific notes.
Project summary
Langfuse MCP server for accessing Langfuse telemetry such as traces, observations, prompts, and datasets via MCP.
The CLI entrypoint is langfuse-mcp, which runs langfuse_mcp.__main__:main using MCPServer.
Repo layout
langfuse_mcp/__main__.py: Core server implementation and tool definitionstests/: Pytest suite; integration tests are marked withpytest.mark.integration
Dev setup (uv)
uv venv --python 3.11 .venv
source .venv/bin/activate
uv pip install -e ".[dev]"
Common commands
uv run python -m langfuse_mcp --public-key YOUR_KEY --secret-key YOUR_SECRET --host https://cloud.langfuse.com
uv run -m pytest
uv run -m ruff format .
uv run -m ruff check --fix .
Supply chain / dependencies
pyproject.tomlsets[tool.uv] exclude-newer = "7 days"as a deliberate supply-chain quarantine:uv lock/uv syncwill not resolve any package version published in the last 7 days, blocking freshly-published malicious versions from landing in dependency resolution. Dependabot'scooldownonly delays generated PRs and does not cover ad-hoc lock/sync — the two are complementary.- The relative-duration syntax (
"7 days","1 week","24 hours") requires uv ≥ 0.9 (added via astral-sh/uv#16814, Dec 2025). Older uv versions emit a parse warning or hard-fail; that is a local-toolchain problem, not a config bug. Bump local uv before assuming the line is broken. - Do not remove
exclude-neweror any other security/supply-chain config as "dead" or "noisy" without confirming what it gates. Investigate root cause (uv version, syntax change) before deleting protections. Past incident: a "follow-up cleanup" PR almost shipped removal of this line.
Release Contract
- Release from
mainonly through./scripts/release.sh X.Y.Zand the resulting release PR; do not create manual tags, GitHub releases, or ad hoc release uploads. - A push to
mainupdates the AvivSinai marketplace immediately for thelangfuseskill. - Keep one version across
CHANGELOG.mdand skill/plugin metadata in the release commit; after merge, CI validates the merged commit, creates the tag, and then publishes the GitHub release plus PyPI and Docker artifacts. The committed changelog entry becomes the GitHub release notes, while the Python package version remains tag-derived viauv-dynamic-versioning.
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 · 62 lines · 813 tokens per session scan A 9af60a278695
langfuse-mcp CLAUDE.md is an instructions file published in the GitHub repository avivsinai/langfuse-mcp (105 stars, last pushed yesterday), licensed MIT. It adds 813 tokens to every session, about $0.0041 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.
Other instructions, from other repositories
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
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.
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).
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.
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).
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.