# x402 Trust: Similar Endpoint Finder

> x402 Trust: Similar Endpoint Finder is a paid API for AI agents from x402-trust.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Returns semantically similar x402 endpoints that score higher than a given subject endpoint, ranked by trust grade and similarity

## Facts

- Endpoint: POST https://x402-trust.com/v1/similar
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-trust-similar-endpoint-finder-383cc420
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ia-rJcgsxlpXt1bkAScuZ

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability x402-trust-similar-endpoint-finder-383cc420 -d '<json body>'
```

Example prompt: Find me up to 5 x402 endpoints that are semantically similar to https://api.example.com/v1/thing but score higher on the x402 Trust index — I want to see alternatives with better grades and reliability.

## When to prefer this

Use this endpoint when you already have an x402 endpoint URL and want to discover higher-quality alternatives ranked by real monitored trust data — uptime, compliance, on-chain settlement volume, and price history. Prefer this over generic API directories when you need trust-scored, x402-specific recommendations with semantic similarity matching rather than keyword search.

## Known failure modes

- Unknown or unindexed endpoint URL returns empty alternatives list or 404
- Invalid resource URL format causes validation error
- limit parameter too large may be capped or return fewer results
- Payment failure (insufficient USDC) results in 402 response with no data
- Endpoint not yet vectorized returns subject with vectorized:false and no alternatives
- Network timeout if probe data is stale or service is under load

## How this service works

Trust, reputation & reliability scores for x402 endpoints. We monitor every listed x402 service 24/7: uptime probes, 402-envelope compliance, price history, and real on-chain USDC settlement volume. Free grade & recommendation for any endpoint, $0.005 for a full data breakdown.

## Output

A JSON object containing the subject endpoint's grade and score, plus a ranked list of semantically similar endpoints that outscore it. Each alternative includes a letter grade (A–F), numeric trust score, network chain ID, USDC price, cosine similarity to the subject, a link to the full endpoint page on x402-trust.com, whether a price ceiling applies, and a proceed/caution recommendation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "limit": {
   "type": "integer"
  },
  "resource": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "note": "Semantically similar endpoints that out-score the subject. Similarity is cosine over description embeddings.",
  "count": 2,
  "subject": {
   "grade": "C",
   "score": 61.2,
   "vectorized": true,
   "inObservationSet": true
  },
  "resource": "https://api.example.com/v1/thing",
  "alternatives": [
   {
    "grade": "A",
    "score": 88.1,
    "network": "eip155:8453",
    "resource": "https://api.better.com/v1/thing",
    "amountUsd": 0.001,
    "similarity": 0.912,
    "endpointPage": "https://x402-trust.com/endpoint/12345",
    "priceCeiling": false,
    "recommendation": "proceed"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-trust-similar-endpoint-finder-383cc420/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-trust.com](https://www.zero.xyz/host/x402-trust.com/llms.txt)