# x402 Clinical Trials Search API

> x402 Clinical Trials Search API is a paid API for AI agents from workspace-x402-paywall.onrender.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-11).

Search FDA/clinical trial data by condition or keyword, returning structured trial information, paid via x402 micropayment at $0.005 USDC per call

## Facts

- Endpoint: GET https://workspace-x402-paywall.onrender.com/health/trials?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-clinical-trials-search-api-1b111cbc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oOBvLcnU9wFgStUCUtZ1O

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-clinical-trials-search-api-1b111cbc
```

Example prompt: Search clinical trials for 'non-small cell lung cancer' and return the name, phase, and status fields for each result.

## When to prefer this

Choose this endpoint when you need lightweight pay-per-call access to clinical trial data without a subscription, especially for sporadic queries. It is ideal for agents that need occasional trial lookups and want to pay fractions of a cent per call via USDC on Base or Solana. Prefer alternatives (ClinicalTrials.gov API, OpenFDA) for high-volume or free access needs.

## Known failure modes

- Missing required 'q' parameter returns an error
- No matching trials for obscure or misspelled condition returns empty results
- Payment failure (insufficient USDC balance) returns HTTP 402
- Service unavailable on Render free tier returns 503 during cold start
- Invalid 'fields' value returns malformed or incomplete response

## How this service works

66 pay-per-call APIs: AI text/image generation ($0.01), Polymarket odds, crypto prices, DeFi yields, FX rates, weather, IP/geo, FBI wanted, SEC tickers, clinical trials, 250M academic papers, Stack Overflow, meme-coin launchpads (pump.fun, Clanker, Four.meme, SunPump), tokenized stocks, Solana top 100, and 40+ more. $0.005/call standard. USDC on Base and Solana via x402.

## Output

A JSON object containing matching clinical trial records for the queried condition or keyword, with fields filtered to those requested (e.g. name, phase, status, sponsor). The exact schema varies by query but follows the standard trials database structure.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "q"
     ],
     "properties": {
      "q": {
       "type": "string",
       "description": "Requires a medical condition or keyword text string"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-clinical-trials-search-api-1b111cbc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from workspace-x402-paywall.onrender.com](https://www.zero.xyz/host/workspace-x402-paywall.onrender.com/llms.txt)