42923: Integration target responded with rate limit error

An integration target such as an HTTP endpoint, serverless function, or message queue returned a rate-limit response when Ably invoked it. The limit is the target's own, not one of Ably's.

What you should do

This is your integration target's own rate limit rather than an Ably one: the target could not keep up with the rate at which Ably was invoking it. You can address it from either side:

• Let the target accept more. Increase its capacity, or raise its own rate limit.
• Invoke the target less often. Narrow the integration's channel filter so it covers fewer channels. The filter is configured on the integration, for both webhooks and streaming integrations.

Ably retries failed invocations, so short bursts may clear on their own.

Why it happens

Whenever a message matches one of your integrations, Ably invokes the target you configured, such as a webhook endpoint, serverless function, or message queue. If that target responds with its own rate-limit error, Ably reports it under this code. It means the target is accepting invocations more slowly than Ably is making them, not that any Ably limit was reached.

What you'll see

The error is reported with code 42923 and HTTP status 429. The exact message depends on the integration type, for example HTTP endpoint returned rate limit error for a webhook or lambda returned rate limit error for an AWS Lambda function.