# ClinicalTrials.gov NCT Study Resolver

> ClinicalTrials.gov NCT Study Resolver is a paid API for AI agents from foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Resolves a single NCT identifier into its current registry status, study phase, dates, and provenance from ClinicalTrials.gov.

## Facts

- Endpoint: POST https://foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev/v2/official/clinicaltrials-study
- 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/clinicaltrials-gov-nct-study-resolver-ce7f421d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fqcT8RA2a2svNFgp5XjxJ

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 clinicaltrials-gov-nct-study-resolver-ce7f421d -d '<json body>'
```

Example prompt: Can you look up the current registry status, phase, and study dates for clinical trial NCT00110383 on ClinicalTrials.gov?

## When to prefer this

Use this endpoint when you need authoritative, up-to-date registry metadata for a single known NCT identifier with explicit provenance and freshness tracking. Prefer it over general web search when you need structured, machine-readable trial data with clear attribution and cache transparency. If you need to search trials by condition rather than a specific NCT ID, use a sibling search endpoint instead.

## Known failure modes

- Invalid NCT ID format (must match ^NCT\d{8}$) returns a validation error
- NCT ID not found in ClinicalTrials.gov returns an empty normalizedResult array
- Network or upstream ClinicalTrials.gov API unavailability may cause timeout or error
- Payment not provided or insufficient USDC results in HTTP 402 rejection

## How this service works

Pay-per-request evidence and data tools: CSV validation and reconciliation, DNS/email configuration evidence, and bounded official weather, earthquake, vehicle, company and study records. Exact USDC prices, explicit JSON contracts and source provenance. No mailbox, ownership, medical or safety guarantees.

## Output

Returns a normalized JSON object containing the NCT study's current registry status, study phase, start and completion dates, source freshness metadata (retrieval timestamp, cache age), attribution and provenance details (license, terms URL, upstream calls), and the raw source identifiers from ClinicalTrials.gov.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "nct_id": {
   "type": "string",
   "pattern": "^NCT\\d{8}$"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "route": "clinicaltrials-study",
  "result": {
   "query": {
    "nct_id": "NCT00110383"
   },
   "source": "ClinicalTrials.gov",
   "freshness": {
    "state": "CURRENT_RETRIEVAL",
    "retrievedAt": "2026-09-06T00:00:00Z",
    "cacheAgeSeconds": 0,
    "maximumCacheSeconds": 0,
    "recordAgeIsNotRetrievalAge": true
   },
   "sourceUrl": "https://clinicaltrials.gov",
   "observedAt": "2026-09-06T00:00:00Z",
   "provenance": {
    "license": "ClinicalTrials.gov terms; bounded factual study metadata only",
    "termsUrl": "https://clinicaltrials.gov/about-site/terms-conditions",
    "truncated": false,
    "attribution": "ClinicalTrials.gov, US National Library of Medicine",
    "limitations": [
     "Synthetic example only; identifiers and null values illustrate fields, not a live observation."
    ],
    "modifications": "Selected factual fields, normalized names and bounded result count; no source ownership claimed.",
    "upstreamCalls": 1,
    "documentationUrl": "https://clinicaltrials.gov/data-api/api"
   },
   "sourceUpdatedAt": null,
   "normalizedResult": [
    {
     "nctId": "NCT00110383",
     "title": null,
     "phases": [],
     "sourceUrl": "https://clinicaltrials.gov/study/NCT00110383",
     "startDate": null,
     "studyType": null,
     "overallStatus": null,
     "completionDate": null,
     "lastUpdatePostDate": null
    }
   ],
   "sourceProcessedAt": null,
   "rawSourceIdentifiers": []
  },
  "observed_at": "2026-09-06T00:00:00Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/clinicaltrials-gov-nct-study-resolver-ce7f421d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev](https://www.zero.xyz/host/foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev/llms.txt)