# med.halowerk.com Trial Sites

> med.halowerk.com Trial Sites is a paid API for AI agents from med.halowerk.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Returns per-site details for a registered clinical trial, including facility name, location, coordinates, site-specific recruitment status, and public contact information.

## Facts

- Endpoint: POST https://med.halowerk.com/v1/trial-sites
- 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/med-halowerk-com-trial-sites-82ffb7b1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_52EUQqdHiMYxZViOm5r8j

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 med-halowerk-com-trial-sites-82ffb7b1 -d '<json body>'
```

Example prompt: Can you pull up all the participating sites for clinical trial NCT04280705 and tell me which ones are still actively recruiting, including their city, country, and any contact info listed?

## When to prefer this

Use this endpoint when you need site-level granularity for a clinical trial rather than trial-level summary data. It is specifically valuable when trial-level recruitment status may differ from individual site status — critical for patient navigation or referral workflows. Prefer this over a general trial search endpoint when you already have a trial identifier and need geographic or contact details per site.

## Known failure modes

- Unknown or malformed trial ID returns an empty site list or 404-equivalent error
- Trial exists but has no site-level data registered — returns empty array
- Registry source temporarily unavailable — upstream timeout or service error
- Trial ID maps to a trial with no publicly listed contacts — contact fields will be null or absent

## How this service works

Returns the participating sites of a registered trial, each with the facility name, city, state and country, the coordinates the registry holds, the recruitment status of that site specifically, and any publicly listed contact. Site status is reported separately from trial status and that separation is the point: a trial can be recruiting overall while the nearest site has stopped, and the reverse happens too, so applying the trial status to every site sends someone to a closed door.

## Output

Returns a list of participating sites for the specified trial, each containing the facility name, city, state, country, geographic coordinates held by the registry, the site-specific recruitment status (independent of overall trial status), and any publicly listed contact name or information.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "lat": {
   "type": "number",
   "maximum": 90,
   "minimum": -90,
   "description": "Reference point for distances."
  },
  "lon": {
   "type": "number",
   "maximum": 180,
   "minimum": -180
  },
  "nct_id": {
   "type": "string",
   "maxLength": 20,
   "minLength": 5
  },
  "country": {
   "type": "string",
   "maxLength": 60
  },
  "recruiting_only": {
   "type": "boolean",
   "default": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/med-halowerk-com-trial-sites-82ffb7b1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from med.halowerk.com](https://www.zero.xyz/host/med.halowerk.com/llms.txt)