I have the same issue,The problem seems due to the ContextualCompressionRetriever,It outputs some info cannot be serialized.

[hpx502766238]

          @maximeperrindev it looks like either the input or output (probably output) of one of the chains is a numpy array. If you want to output it and are sending the data over a web-server, you need to provide a way to encode the data as json.

The easiest thing to do is add another runnable lambda that takes the numpy and outputs a string representation of the numpy that can be sent over the wire (i.e., search online for ways to encode JSON)

Originally posted by @eyurtsev in langchain-ai/langchain#17875 (comment)

[hpx502766238]

INFO: 127.0.0.1:50194 - "POST /stream_log HTTP/1.1" 200 OK
ERROR: Exception in ASGI application
Traceback (most recent call last):
File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/sse_starlette/sse.py", line 269, in call
await wrap(partial(self.listen_for_disconnect, receive))
File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/sse_starlette/sse.py", line 258, in wrap
await func()
File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/sse_starlette/sse.py", line 215, in listen_for_disconnect
message = await receive()
File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/uvicorn/protocols/http/httptools_impl.py", line 553, in receive
await self.message_event.wait()
File "/usr/lib/python3.10/asyncio/locks.py", line 214, in wait
await fut
asyncio.exceptions.CancelledError: Cancelled by cancel scope 7f0a502eba60

During handling of the above exception, another exception occurred:

• Exception Group Traceback (most recent call last):
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/uvicorn/protocols/http/httptools_impl.py", line 399, in run_asgi
  | result = await app( # type: ignore[func-returns-value]
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/uvicorn/middleware/proxy_headers.py", line 70, in call
  | return await self.app(scope, receive, send)
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/fastapi/applications.py", line 1054, in call
  | await super().call(scope, receive, send)
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/starlette/applications.py", line 123, in call
  | await self.middleware_stack(scope, receive, send)
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/starlette/middleware/errors.py", line 186, in call
  | raise exc
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/starlette/middleware/errors.py", line 164, in call
  | await self.app(scope, receive, _send)
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/starlette/middleware/exceptions.py", line 65, in call
  | await wrap_app_handling_exceptions(self.app, conn)(scope, receive, send)
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/starlette/_exception_handler.py", line 64, in wrapped_app
  | raise exc
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
  | await app(scope, receive, sender)
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/starlette/routing.py", line 756, in call
  | await self.middleware_stack(scope, receive, send)
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/starlette/routing.py", line 776, in app
  | await route.handle(scope, receive, send)
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/starlette/routing.py", line 297, in handle
  | await self.app(scope, receive, send)
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/starlette/routing.py", line 77, in app
  | await wrap_app_handling_exceptions(app, request)(scope, receive, send)
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/starlette/_exception_handler.py", line 64, in wrapped_app
  | raise exc
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
  | await app(scope, receive, sender)
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/starlette/routing.py", line 75, in app
  | await response(scope, receive, send)
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/sse_starlette/sse.py", line 255, in call
  | async with anyio.create_task_group() as task_group:
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 680, in aexit
  | raise BaseExceptionGroup(
  | exceptiongroup.ExceptionGroup: unhandled errors in a TaskGroup (1 sub-exception)
  +-+---------------- 1 ----------------
  | RuntimeError: super(): class cell not found
  |
  | The above exception was the direct cause of the following exception:
  |
  | Traceback (most recent call last):
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/sse_starlette/sse.py", line 258, in wrap
  | await func()
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/sse_starlette/sse.py", line 245, in stream_response
  | async for data in self.body_iterator:
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/langserve/api_handler.py", line 1243, in _stream_log
  | "data": self._serializer.dumps(data).decode("utf-8"),
  | File "/mnt/vdb1/app/venv/lib/python3.10/site-packages/langserve/serialization.py", line 168, in dumps
  | return orjson.dumps(obj, default=default)
  | TypeError: Type is not JSON serializable: numpy.float64
  ###################################################
  redundant_filter = EmbeddingsRedundantFilter(embeddings=embeddings)
  relevant_filter = EmbeddingsFilter(embeddings=embeddings, similarity_threshold=0.76)
  pipeline_compressor_fast = DocumentCompressorPipeline(
  transformers=[redundant_filter, relevant_filter]
  )
  compressed_retriever = ContextualCompressionRetriever(
  base_compressor=pipeline_compressor_fast, base_retriever=retriever
  )
  app = FastAPI(
  title="LangChain Server",
  version="1.0",
  description="Spin up a simple api server using Langchain's Runnable interfaces",
  )
  add_routes(app, compressed_retriever,path="/retriever")
  ###################################################
  If I use the original retriever(no compressed),the error won't occur:
  add_routes(app, retriever,path="/retriever")