MCP error -32601 'Method not found': what's actually wrong
Symptom: You see `-32601 Method not found` in the logs, often right after the server connects.
Short answer
-32601 'Method not found' is a protocol mismatch, not your config: the client asked for an MCP method the server doesn't implement. It usually means the server is built on an older (or newer) MCP SDK than the client expects. Update the server package to its latest version — that resolves the large majority of cases.
Why it happens, ranked by how often it's the real cause
1. Outdated server SDK
The server implements an older MCP spec and is missing a method the current client calls.
Fix: Update the package: for npx, the `@latest` tag or clearing the npx cache; for installed packages, upgrade to the newest release.
2. Client/server on different protocol versions
A very new client paired with a stale server (or vice versa) disagree on the method set.
Fix: Update both client and server to current versions so they negotiate the same protocol revision.
Fix it step by step
- 1Note which method 32601 names in the log (it tells you what's missing).
- 2Update the server package to its latest version.
- 3If using npx, force a fresh fetch (clear the npx/_npx cache) so you're not running a cached old build.
- 4Update the client app as well; restart and re-check.
Still stuck?
If it persists after both are current, the server may genuinely not support that capability — check its repo issues for the method name; it may be a known gap rather than something you can configure away.
FAQ
What causes MCP error -32601?
The client called an MCP method the server doesn't implement — almost always a protocol/SDK version mismatch. Updating the server package to its latest version fixes most cases.