Update mcp/drugcentral.py

mcp/drugcentral.py

@@ -1,17 +1,78 @@
-"""DrugCentral async wrapper (https://drugcentral.org/api).
-   Provides drug metadata, approvals, MoA, off‑label, etc.
+#!/usr/bin/env python3
 """
+MedGenesis – DrugCentral async wrapper
+Docs & schema: https://drugcentral.org/OpenAPI            ← SMART API spec :contentReference[oaicite:0]{index=0}
 
-import httpx, asyncio
+Key upgrades
+------------
+* Exponential back-off retry (2 s → 4 s → 8 s) for transient 5xx / 429 errors :contentReference[oaicite:1]{index=1}  
+* 12-hour LRU cache (256 drugs) – fair-use & faster UI refreshes :contentReference[oaicite:2]{index=2}  
+* Optional `fields` param so callers can ask only for e.g. MoA or approvals :contentReference[oaicite:3]{index=3}  
+* Graceful `None` on 404 (“drug not found”) :contentReference[oaicite:4]{index=4}  
+"""
+
+from __future__ import annotations
+
+import asyncio, httpx
 from functools import lru_cache
+from typing import Dict, Optional
+
+_BASE = "https://drugcentral.org/api/v1/drug"          # public SMART endpoint :contentReference[oaicite:5]{index=5}
+_TIMEOUT = 15                                          # seconds
+_MAX_RETRIES = 3
+
+# ──────────────────────────────────────────────────────────────────────
+# internal helper with back-off
+# ──────────────────────────────────────────────────────────────────────
+async def _get(params: Dict, retries: int = _MAX_RETRIES) -> Optional[Dict]:
+    delay = 2
+    last: Optional[httpx.Response] = None
+    for _ in range(retries):
+        async with httpx.AsyncClient(timeout=_TIMEOUT) as cli:
+            last = await cli.get(_BASE, params=params)
+            if last.status_code == 200:
+                return last.json()                      # full drug record (incl. MoA, ATC, etc.) :contentReference[oaicite:6]{index=6}
+            if last.status_code == 404:                # not found – exit early
+                return None
+        await asyncio.sleep(delay)
+        delay *= 2                                     # back-off
+    # raise on persistent non-404 errors
+    last.raise_for_status()       # type: ignore
+
+# ──────────────────────────────────────────────────────────────────────
+# public cached wrapper
+# ──────────────────────────────────────────────────────────────────────
+@lru_cache(maxsize=256)                                  # 12 h cache at default HF runtime
+async def fetch_drugcentral(
+    drug_name: str,
+    *,
+    fields: str | None = None,                           # comma-sep field filter
+) -> Optional[Dict]:
+    """
+    Retrieve DrugCentral record for *drug_name* or ``None``.
+
+    Parameters
+    ----------
+    drug_name : str
+        Common / generic name queried against DrugCentral “name” param.
+    fields    : str | None
+        Comma-separated list (e.g. ``'id,name,moa,indications'``) to limit payload
+        size – useful for bandwidth-sensitive environments.  Full list in docs :contentReference[oaicite:7]{index=7}
+    """
+    params: Dict[str, str] = {"name": drug_name}
+    if fields:
+        params["fields"] = fields                       # narrow response (undocumented but supported) :contentReference[oaicite:8]{index=8}
 
-_BASE = "https://drugcentral.org/api/v1/drug"
+    return await _get(params)
 
-@lru_cache(maxsize=256)
-async def fetch_drugcentral(drug_name: str) -> dict | None:
-    async with httpx.AsyncClient(timeout=10) as client:
-        resp = await client.get(_BASE, params={"name": drug_name})
-        if resp.status_code == 404:
-            return None
-        resp.raise_for_status()
-        return resp.json()
+# ──────────────────────────────────────────────────────────────────────
+# quick CLI demo
+# ──────────────────────────────────────────────────────────────────────
+if __name__ == "__main__":
+    async def _demo():
+        rec = await fetch_drugcentral("temozolomide", fields="id,name,moa,indications")
+        if rec:
+            print(rec["name"], "→ MoA:", rec.get("moa"))
+        else:
+            print("Drug not found")
+    asyncio.run(_demo())