Hi @yyosifov!

Seeing as you need to use both the builds and functions properties together in your vercel.json configuration, you're right - you will need to approach it differently since Vercel does not support using both properties in combination.

You already mentioned trying to use a Function File. What does it look like? This is an example configuration you could try out:

1export const config = {2  maxDuration: 30 // Sets the maximum duration to 30 seconds3};45export default async function handler(req, res) {6  // Your function logic here7  res.status(200).send('Function executed');8}9

Hi @pawlean!

Thanks for the suggestion. I've tried adding this to several places:

1. Added to main.ts - where the bootstrap() of the nest.js is done. It breaks the whole application with an error like this one:

1Invalid export found in module "/var/task/backend/src/main.js".2The default export must be a function or server.

With the other options the application works, but the maxDuration is not applied:

2. Added to app.module.ts which is the entry module of the nest.js app -> It doesn't work
3. Added to test.module.ts which is the module with the test controller I test with - doesn't work
4. Added to test.controller.ts which is the controller I test with

The test is pretty simple - a promise resolved after 25 seconds:

1  @Get('/test-timeout')2  async testTimeout() {3    return new Promise((resolve) => {4      setTimeout(() => {5        resolve('done');6      }, 25000);7    });8  }

Locally it works. When deployed - it timeouts after 10s.

Is there a way I can test it locally somehow? I don't have a typical handler function in a serverless fashion, rather I have Nest.js controllers and I wonder how can I push this maxDuration to the environment to be respected.

Thanks in advance for your kind help!

Best, Yosif

Tagging @eben-bealcoza here, they recently shared that they increased their timeout for their project. I wonder if they may have some insights!

https://community.vercel.com/t/rest-api-with-subdomain/192/6

Thanks for the detail! I'd love to test this out with a minimal reproducible example. I sometimes find that stripping down the application to the bare minimum helps debug problems better.

Also, have you got any logs that may give you some helpful pointers?

For local testing, you could simulate the serverless environment by setting the maxDuration in your local server configuration. A middleware could handle this, similar to:

1import { NestFactory } from '@nestjs/core';2import { AppModule } from './app.module';34async function bootstrap() {5  const app = await NestFactory.create(AppModule);67  // Middleware to simulate maxDuration locally8  app.use((req, res, next) => {9    req.setTimeout(30000); // 30 seconds10    next();11  });1213  await app.listen(3000);14}15bootstrap();

Check the relevant Nest.js documentation.

As far as I know exporting maxDuration won't work as we don't support it in Nest.js. I haven't tested this with Nest.js, but it might be possible to do something like this in vercel.json?

1{2  "functions": {3    "src/main.ts": {4      "runtime": "@vercel/node",5      "maxDuration": 306    }7  }8}

Alternatively you can now configure the default project function timeout. For this head to your Project in the Dashboard and look under Settings > Functions:

Please note that this can impact your billing. Keep the default duration as low as possible to ensure your function execution will be terminated when you have hanging promises or other reasons your code takes a long time to run.

Sorry for the late reply. .. . This is exactly what I did, I tried the config on the dashboard but eventually I added vercel.json to the project with the below config. Not optimised but it is a start.

{ "functions": { "app/api/**/*": { "maxDuration": 60 } } }

This resolved my issue. Hope this helps.