Claude Desktop MCP cost tracking

Claude Desktop config — where to look

Claude Desktop loads MCP servers from claude_desktop_config.json:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

Open it. Most users have 4-8 MCP servers configured. Each one runs as a subprocess every time Claude Desktop launches and stays alive until you quit the app.

The hidden cost: idle MCP servers still charge you

Several MCP servers (filesystem, codebase indexers, github) eagerly fetch context on startup or background-poll for changes. You don't see this in the chat UI — but every fetched token is billed on your next conversation turn because the agent decides whether to read the result.

Worst offenders we've seen in real Claude Desktop configs:

• playwright — keeps a browser context alive; every navigation pulls a full DOM snapshot
• codebase indexers (sourcegraph, codeium) — large initial context dump per session
• github MCPs — list_issues / get_pr returns 50+ items by default

Optimization order

1. Audit your config. Open claude_desktop_config.json and ask: do I actually use each entry weekly? Remove what you don't.
2. Move browser tools to a separate profile. If you have multiple Claude Desktop profiles, keep Playwright on a "browser" profile and a leaner config for everyday chat.
3. Cap GitHub query sizes. Most GitHub MCPs accept --per-page or --max-results. Set it to 10 instead of the default 50-100.
4. Set a $50/month budget alert. Heavy Claude Desktop users without browser tools land at $30-50/month; with browser tools, $100-300/month.

Track your Claude Desktop spend

The MCPSpend proxy auto-detects Claude Desktop's config path and wraps every entry. One command:

npx --yes @mcpspend/proxy@latest init --key mcps_live_xxx

It writes a .mcpspend.bak backup of your original config. Quit and restart Claude Desktop; calls start streaming to the dashboard in under 30 seconds.

Free tier: 25,000 calls / month. No card. MIT-licensed proxy on npm so you can audit what we send.