fal real-time inference bypasses the queue, so queue params stop working and keys stay server-side

TL;DR

When moving a call from the queue to real-time, drop the queue parameters instead of copying them over: no starttimeout, no priority, no webhookurl, no X-Fal-No-Retry, and plan your own error handling because failed messages just return errors on the connection.

Steps

1. When moving a call from the queue to real-time, drop the queue parameters instead of copying them over: no starttimeout, no priority, no webhookurl, no X-Fal-No-Retry, and plan your own error handling because failed messages just return errors on the connection. Never put an API key in browser code that opens a real-time connection. Point the client at a server-side proxy that attaches the key, or implement a tokenProvider returning short-lived tokens, setting tokenExpirationSeconds to match your backend token duration so refresh happens before expiry.

When to use

You are seeing this: Never put an API key in browser code that opens a real-time connection. Use this skill when you run into "fal real-time inference bypasses the queue, so queue params stop working and keys stay server-side".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Source: Official docs (real-time inference): documents the differences agents miss when switching from queue to real-time. Real-time WebSocket connections bypass the queue entirely and connect straight to a runner, so queue parameters silently stop working: starttimeout has no effect with no queue wait, priority does nothing with no queue ordering, webhookurl is not supported since results stream back over the socket, and automatic retries are unavailable. The docs also warn that browser WebSocket connections cannot safely embed API keys, offering a server-side proxy URL or a tokenProvider that fetches short-lived JWTs from your backend.

Verified resolution: When moving a call from the queue to real-time, drop the queue parameters instead of copying them over: no starttimeout, no priority, no webhookurl, no X-Fal-No-Retry, and plan your own error handling because failed messages just return errors on the connection. Never put an API key in browser code that opens a real-time connection. Point the client at a server-side proxy that attaches the key, or implement a tokenProvider returning short-lived tokens, setting tokenExpirationSeconds to match your backend token duration so refresh happens before expiry.

Source URL: https://docs.fal.ai/docs/documentation/model-apis/inference/real-time