fix(mcp): route workspace-qualified memory urls (#790)

Signed-off-by: phernandez <paul@basicmachines.co>

src/basic_memory/api/app.py

@@ -4,6 +4,7 @@ from contextlib import asynccontextmanager
 
 from fastapi import FastAPI, HTTPException, Request
 from fastapi.exception_handlers import http_exception_handler
+from fastapi.responses import JSONResponse
 from fastapi.routing import APIRouter
 from loguru import logger
 
@@ -29,6 +30,12 @@ import logfire
 from basic_memory.config import init_api_logging
 from basic_memory.services.exceptions import EntityAlreadyExistsError
 from basic_memory.services.initialization import initialize_app
+from basic_memory.workspace_context import (
+    WORKSPACE_SLUG_HEADER,
+    WORKSPACE_TYPE_HEADER,
+    workspace_permalink_context_validation_error,
+    workspace_permalink_context,
+)
 
 
 @asynccontextmanager
@@ -87,6 +94,32 @@ app = FastAPI(
     lifespan=lifespan,
 )
 
+
+@app.middleware("http")
+async def workspace_permalink_context_middleware(request: Request, call_next):
+    """Populate workspace permalink context from request headers."""
+    workspace_slug = request.headers.get(WORKSPACE_SLUG_HEADER)
+    workspace_type = request.headers.get(WORKSPACE_TYPE_HEADER)
+
+    validation_error = workspace_permalink_context_validation_error(workspace_slug, workspace_type)
+    if validation_error is not None:
+        return JSONResponse(
+            status_code=400,
+            content={"detail": validation_error},
+        )
+
+    if not workspace_slug:
+        return await call_next(request)
+
+    # ContextVar state remains active across the awaited downstream handler while
+    # this context manager is open, so entity creation can see request metadata.
+    with workspace_permalink_context(
+        workspace_slug=workspace_slug,
+        workspace_type=workspace_type,
+    ):
+        return await call_next(request)
+
+
 # Include v2 routers FIRST (more specific paths must match before /{project} catch-all)
 app.include_router(v2_knowledge, prefix="/v2/projects/{project_id}")
 app.include_router(v2_memory, prefix="/v2/projects/{project_id}")
@@ -146,4 +179,7 @@ async def exception_handler(request, exc):  # pragma: no cover
         error_type=type(exc).__name__,
         error=str(exc),
     )
-    return await http_exception_handler(request, HTTPException(status_code=500, detail=str(exc)))
+    return await http_exception_handler(
+        request,
+        HTTPException(status_code=500, detail="Internal server error"),
+    )