Facebook Sharing Debugger returns 403
piotrkowalski-snlb
PROOP

11 days ago

Subject: Facebook Sharing Debugger returns 403 for facebookexternalhit (Fastly blocking suspected)

Hi Railway Support,

I'm experiencing an issue with Meta's Facebook crawler on my project.

Domain:https://kalendarium.plock24.pl/

Problem:

  • When I test my URLs in the Facebook Sharing Debugger, it returns HTTP 403 with the message: "This response code could be due to a robots.txt block. Please allowlist facebookexternalhit..."

  • However, direct requests with the correct user-agent return 200 OK:

Bash

curl -I -A "facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)" https://kalendarium.plock24.pl/

Response headers (example):

  • server: railway-edge

  • x-railway-cdn-edge: fastly/...

  • x-cache: MISS

I have already:

  • Updated robots.txt to explicitly allow facebookexternalhit

  • Confirmed the site returns correct Open Graph tags

  • Tried multiple "Scrape Again" attempts

This looks like Fastly Bot Protection / WAF is blocking Meta's crawler (or their internal proxy used by the Debugger), even though normal requests work fine.

Could you please allowlist the facebookexternalhit user-agent and Meta crawler IPs on the Fastly edge for my service?

Project ID: 93662279-591b-4948-b41a-9f132a9fd2a8

Thank you in advance!

Solved

4 Replies

Railway
BOT

11 days ago

This thread has been marked as public for community involvement, as it does not contain any sensitive or personal information. Any further activity in this thread will be visible to everyone.

Status changed to Open Railway 11 days ago


javelin-cmd
FREE

11 days ago

not 100% sure on this but this looks like fastly waf blocking at the edge. you can't configure cdn-level bot allowlists yourself, so open a support ticket with your project id and ask railway to allowlist facebookexternalhit


javelin-cmd
FREE

11 days ago

not 100% sure on this but this looks like fastly waf blocking at the edge. you can't configure cdn-level bot allowlists yourself, so open a support ticket with your project id and ask railway to allowlist facebookexternalhit


javelin-cmd
FREE

11 days ago

not 100% sure on this but this looks like fastly waf blocking at the edge. you can't configure cdn-level bot allowlists yourself, so open a support ticket with your project id and ask railway to allowlist facebookexternalhit


We've traced this to Meta/Facebook's side. On our end, the request comes through and we respond with HTTP 200 — but Facebook's debugger reports a 403, which points to something happening after the response leaves us. Since the failure is on their end, it's not something we can fix from here. You'll want to raise this with Meta directly.


Status changed to Solved ray-chen 8 days ago


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