import httpx, asyncio, datetime

_BASE = "https://clinicaltrials.gov/api/v2/studies"

async def search_trials(query: str, max_n: int = 20) -> list[dict]:
    async with httpx.AsyncClient(timeout=15) as cli:
        r = await cli.get(_BASE, params={
            "query": query,
            "pageSize": max_n,
            "fields": "nctId,briefTitle,phase,status,startDate"
        })
    r.raise_for_status()
    return r.json().get("studies", [])