feat: fal_client picks up x-fal-cdn-token header when calling run or submit

projects/fal_client/src/fal_client/_headers.py

@@ -52,3 +52,17 @@ def add_priority_header(priority: Priority, headers: dict[str, str]) -> None:
             f"Priority must be one of {valid_priorities}, got '{priority}'"
         )
     headers[QUEUE_PRIORITY_HEADER] = priority
+
+
+def add_forwarded_headers(request_headers, _headers: dict[str, str]) -> None:
+    if cdn_token := request_headers.get("x-fal-cdn-token"):
+        _headers["x-fal-forwarded-cdn-token"] = cdn_token
+
+    forwarded_request_ids = []
+    if request_ids := request_headers.get("x-fal-forwarded-request-id"):
+        forwarded_request_ids.extend(request_ids.split(","))
+    if request_id := request_headers.get("x-fal-request-id"):
+        forwarded_request_ids.append(request_id)
+
+    if forwarded_request_ids:
+        _headers["x-fal-forwarded-request-id"] = ",".join(forwarded_request_ids)

projects/fal_client/src/fal_client/client.py

@@ -51,6 +51,7 @@
     add_hint_header,
     REQUEST_TIMEOUT_TYPE_HEADER,
     REQUEST_TIMEOUT_HEADER,
+    add_forwarded_headers,
 )
 
 if TYPE_CHECKING:
@@ -62,6 +63,14 @@
 if TYPE_CHECKING:
     from PIL import Image
 
+try:
+    from fal.ref import get_current_app
+except ImportError:
+
+    def get_current_app() -> Optional[Any]:
+        return None
+
+
 AnyJSON = Dict[str, Any]
 UploadRepositoryId = Literal["fal_v3", "cdn", "fal"]
 
@@ -1568,6 +1577,9 @@ async def run(
         if start_timeout is not None:
             add_timeout_header(start_timeout, _headers)
 
+        if (app := get_current_app()) is not None and app.current_request is not None:
+            add_forwarded_headers(app.current_request.headers, _headers)
+
         response = await _async_maybe_retry_request(
             self._client,
             "POST",
@@ -1621,6 +1633,9 @@ async def submit(
         if start_timeout is not None:
             add_timeout_header(start_timeout, _headers)
 
+        if (app := get_current_app()) is not None and app.current_request is not None:
+            add_forwarded_headers(app.current_request.headers, _headers)
+
         response = await _async_maybe_retry_request(
             self._client,
             "POST",
@@ -2064,6 +2079,9 @@ def run(
         if start_timeout is not None:
             add_timeout_header(start_timeout, _headers)
 
+        if (app := get_current_app()) is not None and app.current_request is not None:
+            add_forwarded_headers(app.current_request.headers, _headers)
+
         response = _maybe_retry_request(
             self._client,
             "POST",
@@ -2113,6 +2131,9 @@ def submit(
         if start_timeout is not None:
             add_timeout_header(start_timeout, _headers)
 
+        if (app := get_current_app()) is not None and app.current_request is not None:
+            add_forwarded_headers(app.current_request.headers, _headers)
+
         response = _maybe_retry_request(
             self._client,
             "POST",