mcp-usage

mcp-usage

[CI] [npm] [Node] [License: MIT] [MCP Registry]

[mcp-usage: find out which of your MCP servers you actually use]

A small, focused MCP server and CLI that reads your local Claude Code transcripts and tells you, for every MCP server you have connected, whether it is actually used, sits idle in every session, fails to connect, or has been waiting for authorization for weeks — and what to disconnect.

Built for one job: answer "which of my MCP servers should I keep?" — locally, read-only, without ever exposing a word of your conversations.

Tools

Four tools, all read-only:

Design choices:

• Exact, not guessed. Claude Code already records, in every session, which MCP tools were available and which servers failed or needed auth. "Available but never used" is a set difference over your own logs, not a heuristic.
• Private by construction. No network code at all. The output holds server names, tool names, counts, byte totals and timestamps — never prompts, responses, tool inputs, tool outputs, file paths or error messages. The test fixtures plant SECRET_* markers everywhere private content lives in a real transcript, and the tests assert none of them reach the library, the CLI or the MCP output.
• Fast on big histories. Transcripts are streamed line by line and lines that cannot matter are skipped before JSON.parse: ~360 MB of history (including a 90 MB session) scans in about 3 seconds.
• Hygiene, not billing. Cost analyzers (ccusage, agent-cost-mcp, …) tell you how many tokens and dollars you spent. This tells you which servers earn their place.
• Every tool ships a strict input schema and MCP annotations (readOnlyHint, idempotentHint) so hosts can auto-approve them.

[How mcp-usage works: local transcripts are streamed through a parser into per-server stats, shown as a CLI report or MCP tools]

Requirements

• Node.js 22 or newer.
• Claude Code (CLI, desktop app or IDE extension) with some session history on this machine. Nothing else: no account, no API key, no configuration.

1. Run the report

No install needed, npx fetches the package from npm (@rixtay/mcp-usage, the installed command is mcp-usage):

npx -y @rixtay/mcp-usage

Or from a clone:

git clone https://github.com/Rixtayz/mcp-usage.gitcd mcp-usagenpm install && npm run buildnode dist/bin/cli.js

Text output truncates long lists; --json always contains everything.

2. Connect to Claude Code

claude mcp add --scope user --transport stdio mcp-usage -- npx -y @rixtay/mcp-usage serve

3. Connect to Claude Desktop / Cowork / any MCP client

mcp-usage is listed in the official MCP Registry as io.github.Rixtayz/mcp-usage, so clients that browse the registry can install it by name. Otherwise, configure it by hand:

Edit ~/Library/Application Support/Claude/claude_desktop_config.json on macOS (or %APPDATA%\Claude\claude_desktop_config.json on Windows), reachable through Settings → Developer → Edit Config.

{  "mcpServers": {    "mcp-usage": {      "command": "npx",      "args": ["-y", "@rixtay/mcp-usage", "serve"]    }  }}

If the host cannot find npx (it may not inherit your shell PATH), use absolute paths instead: "command": "/absolute/path/to/node", "args": ["/absolute/path/to/mcp-usage/dist/bin/cli.js", "serve"].

The server reads Claude Code's transcripts wherever it runs, so it only makes sense in local sessions, on the machine where you use Claude Code.

4. Example prompts

• "Which of my MCP servers should I disconnect?"
• "Which servers have been waiting for authorization the longest?"
• "Playwright seems flaky. Which of its tools fail the most?"
• "Did I use anything other than Context7 in the last 7 days?"

Typical flow: recommendations → the assistant proposes a cleanup list, you confirm → server_details on anything surprising → you disconnect the servers yourself. The tools never touch your MCP configuration.

What it reports

Each server gets one status:

Recommendations, in priority order:

Development

npm test          # vitest: name parsing, streaming parser, aggregation, rules, CLI, MCP tools over an in-memory transportnpm run typechecknpm run inspect   # MCP Inspector against the built server

Layout:

src/bin/cli.ts             entry point: `mcp-usage` prints the report, `mcp-usage serve` serves stdiosrc/cli.ts                 argument parsing and outputsrc/server.ts              builds the McpServer and registers the four toolssrc/analyze.ts             options → report; the one function both shells callsrc/parser.ts              streaming JSONL reader → typed eventssrc/aggregate.ts           events → per-server statssrc/recommend.ts           stats → prioritized recommendationssrc/report.ts              text table renderingsrc/scan.ts                transcript discovery (--since, --project)src/adapters/claude-code.ts  the only client-specific code, behind a small ClientAdapter interfacesrc/names.ts               `mcp__<server>__<tool>` parsing and server id mangling

Stack: @modelcontextprotocol/sdk v1, zod v4, nothing else at runtime. Design notes: docs/DESIGN.md.

Things worth knowing

• The transcript format is not a public API. It is parsed defensively — every field optional, unknown records ignored, malformed lines counted and skipped — but a future Claude Code release can still break it. Tested against Claude Code 2.1.233 – 2.1.274.
• Token figures are estimates: result bytes ÷ 4, text only. Transcripts record no per-result token count, and image results are not counted.
• Tool names are split on the first __ after the mcp__ prefix. Server ids can contain underscores, hyphens, dots or be a bare UUID, and tool names can contain __ themselves, so a naive split("__") miscounts.
• The same connector can appear under two names — a readable one in the CLI, a UUID in the desktop app. They are not merged.
• Servers bundled with the Claude desktop app (ccd_*) are reported but never flagged for disconnection: you cannot remove them.
• Claude Code deletes old transcripts, so a long --since window only sees what is still on disk.
• Claude Code only, for now. Adapters for other clients are welcome.

Contributing

Bug reports, fixes and adapters for other MCP clients are welcome: see CONTRIBUTING.md. If Claude Code updates and the report suddenly looks wrong, open a bug with your Claude Code version. Found a way the tool could leak transcript content? Please report it privately, as described in SECURITY.md.

Release history: CHANGELOG.md.

License

MIT