n8n Webhook CORS Issues - Works in Postman, Fails from External Website

tmg-ai
HOBBY

a month ago

Problem: I have an n8n workflow deployed on Railway that works perfectly when tested with Postman, but fails with "Failed to fetch" CORS errors when called from my GitHub Pages website (https://tmg-ai.github.io).

What I've Tried:

  • Added all recommended CORS environment variables:

    • WEBHOOK_CORS_ALLOWED_ORIGINS=*

    • WEBHOOK_CORS_ALLOWED_METHODS=GET,HEAD,POST,PUT,DELETE,OPTIONS

    • WEBHOOK_CORS_ALLOWED_HEADERS=Content-Type,Authorization,X-Requested-With,Accept

    • N8N_EXPRESS_TRUST_PROXY=true

  • Added CORS headers to n8n response node

  • Confirmed webhook authentication is set to "None"

  • Multiple redeployments

Current Status:

  • Webhook works: Postman → Railway n8n

  • Webhook fails: GitHub Pages → Railway n8n (CORS error)

  • Production webhook URL shows 0.0.0.0:80 instead of proper Railway domain

Question: Is there a Railway-specific configuration I'm missing to allow cross-origin requests from external domains? Or is this a known limitation with Railway's networking setup?

Environment: n8n on Railway, single service (not using webhook processor template)

I'm desperate to figure this out since i need full deployment by Monday for a work deadline. This is my first multi-agent workflow deployment.

$10 Bounty

3 Replies

quadstrikesecurity
FREE

a month ago

Try this solution

Set Railway Environment Variables :

# Railway-specific CORS

WEBHOOK_CORS_ALLOWED_ORIGINS=https://tmg-ai.github.io,https://*.github.io

N8N_HOST=0.0.0.0

N8N_PORT=80

N8N_PROTOCOL=https

N8N_WEBHOOK_URL=https://your-app.railway.app

# Force proper URL resolution

RAILWAY_STATIC_URL=https://your-app.railway.app

or else use Reverse Proxy :

// Use Railway as proxy

const proxyUrl = 'https://your-app.railway.app/webhook/proxy';

fetch(proxyUrl, {

method: 'POST',

headers: { 'Content-Type': 'application/json' },

body: JSON.stringify({

target: 'internal_webhook',

data: yourData

})

});

sim
FREETop 10% Contributor

a month ago

Is there a Railway-specific configuration I'm missing to allow cross-origin requests from external domains? Or is this a known limitation with Railway's networking setup?

I do not see anything in their documentation about this

tmg-ai
HOBBY

a month ago

Thank you for the feedback. I had to move my workflow over to Render because I could not get Railway to work. Even though my workflow was perfect running locally on n8n, I had to change a lot of ndoes to get it run. Do most people just build workflows in Railway so there is no need to waste time doing this at deployment?

n8n Webhook CORS Issues - Works in Postman, Fails from External Website - Railway Help Station