Support: Pub/Sub - Document 403 auth response causing FAILED state

[ably-sync-bot]

What

Documents that a 403 response from authUrl or authCallback causes the SDK to transition to the FAILED connection state, stopping automatic reconnection attempts.

Why

This behavior (specified in RSA4d) is not documented. Customers raise support tickets asking how to stop the SDK from retrying connections, for example when a user session is revoked. The answer — return a 403 from the auth server — is not discoverable in the current docs.

Changes

• connect/states.mdx: Expanded the "Fatal errors" section with a bulleted list of fatal error examples (replacing inline examples). Added a paragraph explaining the 403 mechanism for stopping SDK retries.

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Submitted by: Mike Clark (mike.clark@ably.com)
Submitted at: 2026-04-22T11:42:53.282Z
Created via githubCreatePRWithFile MCP tool

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