RAG on live news

"""Ground an answer in live news coverage."""
import requests
from anthropic import Anthropic

BASE = "https://freenewsapi.ai"
client = Anthropic()


def measure(query, window="7d"):
    """Is there enough coverage to be worth the retrieval?"""
    r = requests.get(f"{BASE}/v1/stats", params={"q": query, "date": window}, timeout=30)
    r.raise_for_status()
    return r.json()


def retrieve(query, window="7d", pool=60, **filters):
    """Wide, cheap candidate set \u2014 no bodies yet."""
    r = requests.get(f"{BASE}/v1/search", params={
        "q": query, "date": window, "sort": "relevance",
        "size": pool, "full_text": False, **filters,
    }, timeout=20)
    r.raise_for_status()
    return r.json()["results"]


def rank(candidates, keep=8):
    """Prefer corroborated, recent, well-described articles \u2014 one per publisher."""
    seen_hosts, ranked = set(), []
    for a in sorted(candidates, key=lambda x: x.get("published_at") or "", reverse=True):
        if a["host"] in seen_hosts:          # one voice per publisher
            continue
        if not a.get("description"):         # no summary, probably a stub page
            continue
        seen_hosts.add(a["host"])
        ranked.append(a)
        if len(ranked) >= keep:
            break
    return ranked


def ground(articles):
    """Fetch bodies only for the survivors."""
    out = []
    for a in articles:
        r = requests.get(f"{BASE}/v1/article", params={"url": a["url"]}, timeout=20)
        if r.status_code == 200:
            out.append(r.json())
    return out


def as_context(articles, chars=3000):
    blocks = []
    for i, a in enumerate(articles, 1):
        blocks.append(
            f"[{i}] {a['title']}\n"
            f"Publisher: {a.get('sitename') or a['host']} "
            f"({a.get('country') or 'unknown country'}, {a.get('lang')})\n"
            f"Published: {a['published_at']}\n"
            f"URL: {a['url']}\n\n"
            f"{(a.get('text') or a.get('description') or '')[:chars]}"
        )
    return "\n\n---\n\n".join(blocks)


SYSTEM = """Answer strictly from the numbered articles provided.
Cite every factual claim as [n] with the source URL.
If the articles disagree, present the disagreement rather than picking a side.
If they do not answer the question, say so plainly instead of filling the gap.
Note when coverage comes from a single publisher or a single country."""


def answer(question, query=None, window="7d", **filters):
    query = query or question
    stats = measure(query, window)
    if stats["total"] < 3:
        return f"Not enough coverage: {stats['total']} articles in the last {window}."

    articles = ground(rank(retrieve(query, window, **filters)))
    if not articles:
        return "Found headlines but could not retrieve any article bodies."

    resp = client.messages.create(
        model="claude-opus-5", max_tokens=2048, system=SYSTEM,
        messages=[{"role": "user", "content":
                   f"{as_context(articles)}\n\n---\n\nQuestion: {question}"}],
    )
    return "".join(b.text for b in resp.content if b.type == "text")


print(answer("What is driving the change in grain export prices?",
             query="grain export prices", window="7d", lang="en"))