HTTP 428 Precondition Required

Client Error

The server requires the request to be conditional (include If-Match or If-Unmodified-Since headers) to prevent lost updates.

Common Causes

Server requires optimistic concurrency control
API mandates conditional requests for updates

How to Fix

Include If-Match header with the resource's current ETag
Fetch the resource first to get the ETag, then update

Related Status Codes

412 Precondition Failed 409 Conflict

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