Fix OpenAPI schema for ChatGPT Actions support

diffcontext-service/backend/main.py

@@ -51,6 +51,15 @@ class InlineRequest(BaseModel):
     files: Dict[str, str]   # filename -> source code
     symbol: str             # which function to analyze
 
+class HealthResponse(BaseModel):
+    status: str
+
+class RootResponse(BaseModel):
+    service: str
+    docs: str
+    endpoints: List[str]
+
+
 
 # ── Helpers ─────────────────────────────────────────────────────────────────
 
@@ -227,7 +236,7 @@ def _list_symbols(repo_path: str) -> List[str]:
 
 # ── Routes ───────────────────────────────────────────────────────────────────
 
-@app.get("/")
+@app.get("/", response_model=RootResponse)
 def root():
     return {
         "service": "DiffContext API",
@@ -243,11 +252,12 @@ def root():
     }
 
 
-@app.get("/health")
+@app.get("/health", response_model=HealthResponse)
 def health():
     return {"status": "ok"}
 
 
+
 @app.post("/upload")
 async def upload_repo(file: UploadFile = File(...)):
     """
@@ -433,3 +443,37 @@ try:
 except ImportError:
     pass
 
+
+# ── Custom OpenAPI schema for ChatGPT Actions ────────────────────────────────
+from fastapi.openapi.utils import get_openapi
+
+def custom_openapi():
+    if app.openapi_schema:
+        return app.openapi_schema
+
+    schema = get_openapi(
+        title="DiffContext API",
+        version="1.0.0",
+        description="Analyse your Python code's blast radius — which functions break when you change one?",
+        routes=app.routes,
+    )
+
+    # Force the mandatory servers URL for GPT Actions
+    schema["servers"] = [
+        {
+            "url": "https://trakshan-diffcontext.hf.space"
+        }
+    ]
+
+    # Exclude SSE / message endpoints from GPT Actions schema
+    paths = schema.get("paths", {})
+    paths_to_remove = [p for p in paths if p.startswith("/sse") or p.startswith("/messages")]
+    for p in paths_to_remove:
+        paths.pop(p, None)
+
+    app.openapi_schema = schema
+    return schema
+
+app.openapi = custom_openapi
+
+