# TrialBase DB Coverage

> TrialBase DB Coverage is a paid API for AI agents from TrialBase DB at api.trialbase-db.org, paid per call via MPP, $0.25/call, status unknown (last checked 2026-09-13).

Retrieves the dated TrialBase coverage contract detailing release size, registry counts, identity matching statistics, and field fill rates across clinical trial registries.

## Facts

- Endpoint: GET https://api.trialbase-db.org/v1/coverage
- Price: $0.25/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Provider: TrialBase DB
- Docs: https://trialbase-db.org
- Website: https://trialbase-db.org
- Tags: clinical-trials, registries, healthcare, research, provenance, data, search
- Canonical page: https://www.zero.xyz/c/trialbase-db-coverage-88874ada
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dI_lAUoQLo4A3nTf5oevC

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 trialbase-db-coverage-88874ada
```

Example prompt: Can you pull the latest TrialBase coverage report so I can see how many trials are indexed per registry, what the field fill rates look like, and when the dataset was last released?

## When to prefer this

Use this endpoint when you need to audit or verify the completeness, freshness, and scope of the TrialBase clinical trial dataset — especially before running searches to understand how many trials are indexed, how recently the data was released, and how well fields are populated across supported registries.

## Known failure modes

- Service unavailable returns HTTP 503
- Payment not processed returns HTTP 402 requiring USDC payment
- Rate limiting returns HTTP 429
- Malformed response if coverage data has not yet been generated for the current release

## How this service works

Retrieve the dated TrialBase coverage contract with release size, registry counts, identity matching, and measured field fill.

## Output

Returns a dated coverage contract object containing the release date, total release size, per-registry trial counts (ClinicalTrials.gov, CTIS, EudraCT, ISRCTN), identity matching statistics across registries, and measured field fill rates indicating data completeness.

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/trialbase-db-coverage-88874ada/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.trialbase-db.org](https://www.zero.xyz/host/api.trialbase-db.org/llms.txt)