Observed arrival · 2026-09-06

mcpschemer watches MCP servers for schema drift

mcpschemer.dev Observed source

Editorial interest 84/100 Selection signal · not a rating of the site

A local CLI and planned hosted monitor that checks remote MCP endpoints, records their tool schemas, and flags changes that could break agent workflows.

Landing page captured for the 2026-09-06 issue.

Field notes

The local command performs MCP handshakes over both Streamable HTTP and HTTP+SSE, then saves endpoint snapshots under ~/.mcp-drift-check for later comparison. Its severity model treats removed tools and changed inputSchema values as breaking, while altered descriptions receive warnings because they influence model tool selection. The homepage reports 17,317 endpoints in its first pass and offers telemetry opt-outs through --no-telemetry or DO_NOT_TRACK=1.

Observed signals

Read the marks

Editorial observations of this landing page, not a rating.

○OpenPublic substance visible

$PaidCommerce or pricing visible

✦PrettyNotable craft visible

●ProPolished or operationally mature

◎NicheUnusually specific use

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