# What breaks in MCP servers: results from launching 750 registry entries

> Source: <https://dev.to/mcpverified/what-breaks-in-mcp-servers-results-from-launching-750-registry-entries-h0p>
> Published: 2026-10-23 14:10:29+00:00

*Disclosure: I run MCP Verified, a weekly test of servers in the official Model Context Protocol registry. This post is the data. The newsletter link is at the end.*

Each week we take a sample of 750 entries from the official MCP registry (300 npm, 150 PyPI, 200 remote streamable-HTTP, 100 remote SSE). We install or connect to each one in a clean sandbox, run the MCP initialize handshake, and call `tools/list`. Where possible we also make one harmless tool call. We supply no API keys.

| Type | Tested | Working | Median handshake | Median tools | 
|---|---|---|---|---|
| npm | 300 | 218 (73%) | 563 ms | 14 | 
| PyPI | 150 | 73 (49%) | 1,581 ms | 16 | 
| HTTP | 200 | 130 (65%) | 436 ms | 8.5 | 
| SSE | 100 | 10 (10%) | 1,152 ms | 9 | 
| **All** | **750** | **431 (57%)** |  |  | 

| Reason | Count | 
|---|---|
| Needs config/env vars (untested) | 92 | 
| Remote endpoint dead | 88 | 
| Needs credentials (untested) | 54 | 
| Crashed on start | 47 | 
| Install failed | 12 | 
| Handshake failed | 10 | 
| tools/list failed after handshake | 6 | 
| URL isn't an MCP server | 6 | 
| Timeout (45 s) | 4 | 

Working count in our runs: 422 (Oct 13), then 427, then 431 (both Oct 19).

This is a sample, not the whole registry. "Needs config" doesn't mean broken. Results are from one sandbox environment.

Weekly results (free newsletter): [https://buttondown.com/mcpverified](https://buttondown.com/mcpverified) · Site: [https://mcpverified.netlify.app](https://mcpverified.netlify.app)