How can I configure the OAUTH callback URL in n8n Docker behind a Cloudflared CDN without forcing port 443?

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I am running n8n in Docker behind a Cloudflared tunnel and facing issues with the OAUTH callback URL setup.

Setup:
Internet → https://public-url:443 → Cloudflared tunnel forwards to http://localhost:5678 → Docker maps port 5678 to the n8n container.

The generated OAUTH callback URL by n8n is "https://public-url:5678/rest/oauth2-credential/callback", which is not handled by Cloudflare because it expects traffic on port 443. In an attempt to fix this, I tried changing the environment variables in Docker to:

BASH
-e N8N_HOST="public-url"
-e N8N_PROTOCOL="https"
-e N8N_PORT="443"
-e WEBHOOK_TUNNEL_URL="public-url"
-e VUE_APP_URL_BASE_API="public-url"

This change makes the entire n8n instance run on port 443 instead of just updating the OAUTH callback URL, which is not the desired outcome. The only workaround so far has been to either accept running on port 443 or to have Cloudflare forward port 5678 publicly (which is not ideal for security).

The error encountered is: OAuth 501 timeout

Current n8n Docker container environment on Debian Linux:

BASH
sudo docker exec -it n8n env | grep -E "N8N|VUE_APP"
N8N_HOST=n8n.maziak.eu
N8N_PROTOCOL=https
N8N_PORT=5678
VUE_APP_URL_BASE_API=https://n8n.maziak.eu
N8N_VERSION=1.74.3
N8N_RELEASE_TYPE=stable

How can I adjust the settings so that only the OAUTH callback URL uses port 443 while keeping other configurations intact?

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Answers 1

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1 Answer

Answer by StackOverflow TychoAI Agent • 14 days ago

You can solve the issue without forcing the entire n8n instance to run on port 443 by leaving the internal port unchanged (N8N_PORT = 5678) and instead explicitly setting the public base URL for webhooks. This way, n8n will generate webhook (and OAuth callback) URLs that use port 443 (the default for HTTPS) while still running on port 5678 internally.

To do this, remove the N8N_PORT override from your public URL settings and add the environment variable WEBHOOK_URL with your public URL. For example, update your Docker environment variables as follows:

BASH
-e N8N_HOST="public-url"
-e N8N_PROTOCOL="https"
-e N8N_PORT="5678"                   # Keep internal port unchanged
-e WEBHOOK_URL="https://public-url"  # Overrides callback URL to use HTTPS default (443)
-e VUE_APP_URL_BASE_API="https://public-url"

This tells n8n to listen on port 5678 inside the container but to generate external webhook (and OAuth callback) URLs as “https://public-url/…”, which in effect uses HTTPS (and thus port 443). With this change, Cloudflared will correctly handle the incoming HTTPS traffic on port 443 and forward it to your local n8n instance on port 5678.

Remember to restart the container after applying these changes.

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