Persistent 503 Service Unavailable on X

Questions
1

Hi everyone,

I’m facing a persistent 503 Service Unavailable error when trying to post a tweet via n8n. Despite successfully authenticating, every attempt to execute the node fails.

My Setup:

  • n8n Version: 2.8.3 (Self-hosted via Docker)

  • Environment: Subdomain with valid SSL/HTTPS.

  • X API Plan: Free Tier (not Pay Per Use).

  • Permissions: Set to Read and Write (re-generated tokens after changing permissions).

What I have tried (The “Deep Dive”):

  1. Official n8n Nodes: I started by using the native X (Twitter) node with both the built-in X OAuth1 and X OAuth2 credential types. In both cases, the authentication was successful, but the execution consistently triggered the 503 Service Unavailable error.

  2. Generic OAuth 2.0 (PKCE): I then tried the HTTP Request node with a Generic OAuth2 credential using Client ID/Secret and scopes: tweet.read, tweet.write, users.read, offline.access. The authentication flow completed successfully (“Connection Successful”), but execution still returned 503.

  3. Generic OAuth 1.0a: I also tried a manual OAuth 1.0a configuration with all 4 keys (Consumer Key/Secret & Access Token/Secret). Again, the connection was successful, but the execution failed.

  4. Endpoints: Tested both https://api.twitter.com/2/tweets (v2) and https://api.twitter.com/1.1/statuses/update.json (v1.1). The v1.1 endpoint returns a 403 (as expected for Free Tier), but v2 consistently returns 503.

  5. Headers: Added a custom User-Agent (mimicking a Chrome browser) to the HTTP Request to rule out basic bot-filtering.

  6. Retry Logic: Implemented “Retry on Fail” settings with up to 10 tries and 30s intervals.

  7. Cooldown Period: Waited for more than 6 hours between attempts to ensure my server’s IP wasn’t temporarily rate-limited or flagged.

The error details from the node: 503 - {"title":"Service Unavailable","detail":"Service Unavailable","type":"about:blank","status":503}

I’ve verified that the tweets are not actually being posted. Since authentication works but the POST request fails with 503, I’m wondering if this is a known issue with the X Free Tier for certain IP ranges or if there’s a specific header/JSON formatting quirk in this n8n version that X’s load balancer dislikes.

Has anyone managed to bypass this 503 error on a self-hosted instance recently?

1 Like
2

Hey, this isn’t on your end at all — X’s v2 API has been throwing 503s for a bunch of developers since around February 28th. It’s a platform-side outage affecting POST /2/tweets regardless of auth method or API tier, which lines up perfectly with what you’re seeing (auth works, execution fails). There’s a thread tracking it on the X Dev Community forum here: 503 errors since 2/28 - API Status - X Developers — not much to do besides wait for them to fix it unfortunately.

1 Like
4

Reading the link that you sended it seems like this is not an error but a change of strategy by X with the free tier.

5

Hi @King_Pyrros. I guess now you need to add Pay as you Go in your X package, as again this is not an n8n side error as the error suggests 503. This does not have anything related to permissions as the requested services is not available instead of 404 you getting 503, so just upgrade your plan.