Can't fetch from Node.js + express app on Heroku

[Alexey_Chekano1]

I’m developing an API on Node.js + express on Heroku, and every time I fetch anything with POST, I get a 400 Bad request error.

Postman requests to the same endpoint work perfectly. So the only hypothesis I have is that I need a ‘Host’ header in my Airtable request (when I remove the ‘Host’ header in Postman. I get the same 400 Bad request error), but I don’t know what this ‘Host’ header should be.

To reproduce:

1. Create a simple Node.js+express app on Heroku where you return the same body as you get:

app.post('/', (request, response) => {
 response.status(200).send(request.body);
})

2. Create Airtable automation with fetch (or an app with remoteFetchAsync):

let response = await fetch('https://....herokuapp.com/api/', {
                    method: 'POST',
                    body: JSON.stringify('Hello World!'),
                    headers: {
                        'Content-Type': 'application/json; charset=UTF-8',
                        'Accept': 'application/json'
                    },
                });
console.log(await response.text());

You’ll get a ‘400 Bad Request’ response.

[Alexey_Chekano1 · Accepted solution]

Solved!

I had to add 'Host': 'https://*.airtableblocks.com' header.

await remoteFetchAsync('https://....herokuapp.com/api/', {
                    method: 'POST',
                    body: requestBody,
                    headers: {
                        'Content-Type': 'application/json; charset=UTF-8',
                        'Host': 'https://*.airtableblocks.com',
                        'Accept': 'application/json'
                    },
                })