How we check and score
Every number on a listing comes from a check we ran or a public source we name. Here is exactly how.
The checks
For an x402 endpoint we send one unpaid request with the example input it publishes. A correct server answers HTTP 402 with a payment challenge before running anything. We parse the challenge (v1 body or v2 PAYMENT-REQUIRED header) and record status, response time, price, token, network and pay-to address. We never pay.
For an MCP server we run the MCP handshake (initialize, then tools/list) and record the tools it exposes. Servers that require sign-in count as reachable.
Verified, featured and actively used services are checked every 30 minutes, others every few hours, and services that keep failing less often. Requests come from ToolVetProbe/1.0 (+https://toolvet.app/methodology).
The trust score
87trustA yellow tag means the latest check passed. Grey means it failed or hasn't run yet.
x402 endpoints
| Availability (30-day uptime) | 30 pts |
|---|---|
| Valid x402 challenge | 15 pts |
| Response time | 10 pts |
| Real paying agents (30 days) | 15 pts |
| Charges what it lists | 10 pts |
| Security scan | 10 pts |
| Verified owner | 10 pts |
MCP servers
| Availability (30-day uptime) | 35 pts |
|---|---|
| Response time | 15 pts |
| Security scan | 20 pts |
| Transparency (repo, homepage, docs) | 15 pts |
| Recently checked | 5 pts |
| Verified owner | 10 pts |
- Availability is the share of passed checks over 30 days.
- Response time: 300 ms or less earns full points, over 2 seconds none.
- Real usage counts unique paying wallets over 30 days from the x402 Bazaar, on a log scale, so a handful of self-payments barely moves it.
- Honest pricing: you lose these points if the live price is more than 10% above the advertised one.
The security scan
We scan names, descriptions and MCP tool definitions for patterns used to manipulate agents:
- Hidden instruction tags
- Tries to override the agent's instructions
- Asks the agent to hide things from the user
- Mentions credentials or secret files
- Tries to override other tools
- Tries to manipulate payment behaviour
- Invisible Unicode characters
- Unusually long description
- Charges more than its listed price
- Payment address changed recently
- Served over plain HTTP
- Asks for an unrecognised token
Findings are shown on the listing with the exact text that triggered them.
Ranking and sponsorship
Search ranks by text relevance (60%), trust score (30%) and real usage (10%), and pushes services that are failing right now down. Featured listings appear in separate, labelled sponsored slots; paying never changes the organic order or a score.
Corrections
If a check is wrong, contact [email protected] with the listing URL.