NodeJS and Python Serverless Funciton in same project

Hello,

I have a Nodejs project which contains some serverless functions within api/ and its working fine. I also have a Python script that I would like to include in my project as a python serverless funciton. I've tried a few things and they didn't work so, I went through a few other help threads and have tried their suggestions but so far the suggestions haven't worked for me.

I can explain what I've tried and show the settings for my files but before doing that I want to know if this is true:

Within one of the help threads: https://community.vercel.com/t/python-script-within-nodejs-app/4068/2 Anshuman Bhardwaj mentions the following:

Is it really impossible to be able to have a Python serverless function alongside NodeJs serverless functions within /api? Can't we just configure which runtime to use for a specific serverless function? My project isn't using any framework, just Typescript and Python.

If there is a way to have Python and NodeJs serverless functions within the same project please let me know so I can share more details.

Hi , thanks for asking this question.

To clarify, you can keep Python and Node.js serverless functions in the same project. The question that you linked was about using Python script inside a Node.js function, which is not supported because each function has a dedicated runtime.

This is a project that I've which has both Python and Node.js functions

Python and Node.js serverless functions

I hope this answers your question.

Thank you for the response and I apologize for misreading the other help thread.

I deployed a project that contains Node & Python serverless functions to Vercel and both endpoints work. However, when developing locally using the Vercel CLI I keep getting, this huge error:

when accessing http://localhost:8071/api/node

1 vercel dev --listen 80802Vercel CLI 41.2.23> Ready! Available at http://localhost:80804Server is running on http://localhost:30005file:///C:/Users/o0/.bun/install/global/node_modules/@vercel/node/dist/dev-server.mjs:11336    return listener(req, res);7           ^8TypeError: listener is not a function9    at Server.<anonymous> (file:///C:/Users/o0/.bun/install/global/node_modules/@vercel/node/dist/dev-server.mjs:1133:12)10    at processTicksAndRejections (node:internal/process/task_queues:95:5)11This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason:12Error: Command failed: taskkill /pid 1808 /T /F13ERROR: The process "1808" not found.1415    at ChildProcess.exithandler (node:child_process:422:12)16    at ChildProcess.emit (node:events:517:28)17    at ChildProcess.emit (node:domain:489:12)18    at maybeClose (node:internal/child_process:1098:16)19    at ChildProcess._handle.onexit (node:internal/child_process:303:5)20Error: An unexpected error occurred!21Error: Command failed: taskkill /pid 1808 /T /F22ERROR: The process "1808" not found.2324    at ChildProcess.exithandler (node:child_process:422:12)25    at ChildProcess.emit (node:events:517:28)26    at ChildProcess.emit (node:domain:489:12)27    at maybeClose (node:internal/child_process:1098:16)28    at ChildProcess._handle.onexit (node:internal/child_process:303:5)

and when accessing http://localhost:8071/api/python

1 vercel dev --listen 80712Vercel CLI 41.2.23> Ready! Available at http://localhost:80714> Building @vercel/python@latest:api/main_flow.py5Installing required dependencies...6> Built @vercel/python@latest:api/main_flow.py [3s]7AssignProcessToJobObject: (87) The parameter is incorrect.8LambdaError: RequestId: a3e98b22-7754-4aa4-aa3b-c7966447871f Process exited before completing request9    at Lambda.<anonymous> (C:\Users\o0\.bun\install\global10ode_modules\@vercel\fun\dist\src\index.js:114:27)11    at Generator.next (<anonymous>)12    at fulfilled (C:\Users\o0\.bun\install\global13ode_modules\@vercel\fun\dist\src\index.js:28:58)14    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)15using HTTP Handler16Traceback (most recent call last):17  File "C:\Python311\Lib\urllib\request.py", line 1348, in do_open18    h.request(req.get_method(), req.selector, req.data, headers,19  File "C:\Python311\Lib\http\client.py", line 1282, in request20    self._send_request(method, url, body, headers, encode_chunked)21  File "C:\Python311\Lib\http\client.py", line 1328, in _send_request22    self.endheaders(body, encode_chunked=encode_chunked)23  File "C:\Python311\Lib\http\client.py", line 1277, in endheaders24    self._send_output(message_body, encode_chunked=encode_chunked)25  File "C:\Python311\Lib\http\client.py", line 1037, in _send_output26    self.send(msg)27  File "C:\Python311\Lib\http\client.py", line 975, in send28    self.connect()29  File "C:\Python311\Lib\http\client.py", line 941, in connect30    self.sock = self._create_connection(31                ^^^^^^^^^^^^^^^^^^^^^^^^32  File "C:\Python311\Lib\socket.py", line 850, in create_connection33    raise exceptions[0]34  File "C:\Python311\Lib\socket.py", line 835, in create_connection35    sock.connect(sa)36ConnectionRefusedError: [WinError 10061] No connection could be made because the target machine actively refused it3738During handling of the above exception, another exception occurred:3940Traceback (most recent call last):41  File "C:\Users\o0\AppData\Local\com.vercel.fun\Cache\runtimes\python\bootstrap.py", line 147, in <module>42    lambda_runtime_main()43  File "C:\Users\o0\AppData\Local\com.vercel.fun\Cache\runtimes\python\bootstrap.py", line 130, in lambda_runtime_main44    (event, context) = lambda_runtime_next_invocation()45                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^46  File "C:\Users\o0\AppData\Local\com.vercel.fun\Cache\runtimes\python\bootstrap.py", line 56, in lambda_runtime_next_invocation47    res = LambdaRequest('invocation/next')48          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^49  File "C:\Users\o0\AppData\Local\com.vercel.fun\Cache\runtimes\python\bootstrap.py", line 31, in __init__50    req = urllib.request.urlopen(url, data)51          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^52  File "C:\Python311\Lib\urllib\request.py", line 216, in urlopen53    return opener.open(url, data, timeout)54           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^55  File "C:\Python311\Lib\urllib\request.py", line 519, in open56    response = self._open(req, data)57               ^^^^^^^^^^^^^^^^^^^^^58  File "C:\Python311\Lib\urllib\request.py", line 536, in _open59    result = self._call_chain(self.handle_open, protocol, protocol +60             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^61  File "C:\Python311\Lib\urllib\request.py", line 496, in _call_chain62    result = func(*args)63             ^^^^^^^^^^^64  File "C:\Python311\Lib\urllib\request.py", line 1377, in http_open65    return self.do_open(http.client.HTTPConnection, req)66           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^67  File "C:\Python311\Lib\urllib\request.py", line 1351, in do_open68    raise URLError(err)69urllib.error.URLError: <urlopen error [WinError 10061] No connection could be made because the target machine actively refused it>

I changed up the ports because I thought it might have to do with ports being in use. Long errors, I just wanted to share but maybe I'm just tired since its late here, I'll take a look at these tomorrow and update.

Note: I installed the Vercel CLI using Bun, I don't know if that might be the issue.

Hi , are you able to start these individual files using node and python directly?

If you need more help, please share your public repo or a minimal reproducible example. That will let us all work together from the same code to figure out what’s going wrong.

Hey, I managed to make some progress but I'm still doing something wrong. This repository: https://github.com/NazCodeland/vite-vercel works when I push it to Vercel.

I can access the api/node and api/python but when I am running it locally, I can only access api/node and when I try to access api/python I get the following error:

1404: NOT_FOUND2Code: NOT_FOUND3ID: dev1::m0dro-1740772524199-12ed8c11ac38

Hmm, I just tried deploying the hello-world Python template and that is also erroring when I run it locally but works when hosted on Vercel, accesed via *.vercel.app url.

But the error is different, when I go to http://localhost:3000/api it shows

1502: BAD_GATEWAY2Code: NO_RESPONSE_FROM_FUNCTION3ID: dev1::dev1::11jq7-1740773958622-87294de9dd2d456Check the logs in your terminal window to see the application error.

in the terminal:

1vercel dev2Vercel CLI 41.2.23? Set up and develop “~\source\developer\projects\mine\vanilla\python-hello-world”? yes4? Which scope should contain your project? nazcodeland's projects5? Found project “nazcodelands-projects-bac6b4e1/python-hello-world”. Link to it? yes6🔗  Linked to nazcodelands-projects-bac6b4e1/python-hello-world (created .vercel and added it to .gitignore)7> Ready! Available at http://localhost:30008> Building @vercel/python@latest:api/index.py9Installing required dependencies...10> Built @vercel/python@latest:api/index.py [5s]11AssignProcessToJobObject: (87) The parameter is incorrect.12LambdaError: RequestId: e2793808-9871-48fe-81b5-62fae5e3df19 Process exited before completing request13    at Lambda.<anonymous> (C:\Users\o0\.bun\install\global14ode_modules\@vercel\fun\dist\src\index.js:114:27)15    at Generator.next (<anonymous>)16    at fulfilled (C:\Users\o0\.bun\install\global17ode_modules\@vercel\fun\dist\src\index.js:28:58)18    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)19using HTTP Handler20Traceback (most recent call last):21  File "C:\Python311\Lib\urllib\request.py", line 1348, in do_open22    h.request(req.get_method(), req.selector, req.data, headers,23  File "C:\Python311\Lib\http\client.py", line 1282, in request24    self._send_request(method, url, body, headers, encode_chunked)25  File "C:\Python311\Lib\http\client.py", line 1328, in _send_request26    self.endheaders(body, encode_chunked=encode_chunked)27  File "C:\Python311\Lib\http\client.py", line 1277, in endheaders28    self._send_output(message_body, encode_chunked=encode_chunked)29  File "C:\Python311\Lib\http\client.py", line 1037, in _send_output30    self.send(msg)31  File "C:\Python311\Lib\http\client.py", line 975, in send32    self.connect()33  File "C:\Python311\Lib\http\client.py", line 941, in connect34    self.sock = self._create_connection(35                ^^^^^^^^^^^^^^^^^^^^^^^^36  File "C:\Python311\Lib\socket.py", line 850, in create_connection37    raise exceptions[0]38  File "C:\Python311\Lib\socket.py", line 835, in create_connection39    sock.connect(sa)40ConnectionRefusedError: [WinError 10061] No connection could be made because the target machine actively refused it4142During handling of the above exception, another exception occurred:4344Traceback (most recent call last):45  File "C:\Users\o0\AppData\Local\com.vercel.fun\Cache\runtimes\python\bootstrap.py", line 147, in <module>46    lambda_runtime_main()

at least with this it tried to build and install dependencies,

1> Building @vercel/python@latest:api/index.py2Installing required dependencies...3> Built @vercel/python@latest:api/index.py [5s]4...

whereas in the template I made using vercel init https://github.com/NazCodeland/vite-vercel it doesn't even try to build/install when I try to access the api/python locally.