Borrowing it
Nothing to install: this file belongs to chrischall/musicbrainz-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/chrischall/musicbrainz-mcp/main/CLAUDE.mdgit clone --depth 1 https://github.com/chrischall/musicbrainz-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/chrischall/musicbrainz-mcp/claude-md)<a href="https://agentmods.dev/instructions/chrischall/musicbrainz-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/chrischall/musicbrainz-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/chrischall/musicbrainz-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/chrischall/musicbrainz-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 | $0.01960 | $0.01960 |
| Opus 5 | $0.00980 | $0.00980 |
| Sonnet 5 | $0.00392 | $0.00392 |
| Haiku 4.5 | $0.00196 | $0.00196 |
Grade A, and why
musicbrainz-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 — 105 lines — stays where its author put it; the contents beside it link to each section on GitHub.
musicbrainz-mcp
MCP server for MusicBrainz, the open music encyclopedia. Wraps the /ws/2 REST API (https://musicbrainz.org/ws/2) plus the Cover Art Archive and exposes 9 tools to Claude over stdio: 6 read-only (search/lookup/browse/cover-art/resolve/healthcheck) and 3 OAuth-authenticated, confirm-gated writes (tags, ratings, collections).
Commands
npm run build # tsc + esbuild bundle → dist/index.js + dist/bundle.js
npm test # tsc typecheck + vitest run
npm run test:watch # vitest watch
npm run test:coverage # tsc typecheck + vitest run --coverage (v8 reporter, no thresholds)
Run locally (requires built dist/):
node dist/index.js # reads work with no creds; writes need MUSICBRAINZ_OAUTH_*
Tool naming
All tools are prefixed musicbrainz_ and use a generic entity-enum shape rather than per-entity tools: musicbrainz_search / _lookup / _browse take an entity argument covering all 13 core MusicBrainz entities.
Architecture
src/
version.ts # single source of truth for VERSION (x-release-please-version)
index.ts # MCP server entry — runMcp({ name, version, banner, tools })
client.ts # MusicBrainzClient — reads (no auth), Cover Art Archive, OAuth + XML writes; throttled ≥1.1s
entities.ts # entity enums + MBID schema shared across tools
xml.ts # mmd-2.0 submission XML builders (tags / ratings)
attribution.ts # ATTRIBUTION_NOTE appended to data tool descriptions
tools/
lookup.ts # musicbrainz_lookup
search.ts # musicbrainz_search
browse.ts # musicbrainz_browse
coverart.ts # musicbrainz_cover_art (Cover Art Archive)
resolve.ts # musicbrainz_resolve (URL → entity)
utilities.ts # musicbrainz_healthcheck
tags.ts # musicbrainz_submit_tags (OAuth, confirm-gated)
ratings.ts # musicbrainz_submit_rating (OAuth, confirm-gated)
collections.ts # musicbrainz_modify_collection (OAuth, confirm-gated)
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 · 105 lines · 1,960 tokens per session scan A e17d7c117b97
musicbrainz-mcp CLAUDE.md is an instructions file published in the GitHub repository chrischall/musicbrainz-mcp (0 stars, last pushed today), licensed MIT. It adds 1,960 tokens to every session, about $0.0098 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.
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