*the maximum rate at which messages can be published to a queue*
| 250 | 250 | 1,000 | Custom | | **Queue TTL (hours)***the maximum time that a message is stored in a queue for, before being transferred to the dead letter queue*
| 24 | 24 | 24 | 24 | +## Before publish rules limits + +Before publish rules limits relate to the rate and concurrency of [before publish rules](/docs/chat/moderation/custom), such as those used for custom chat moderation. Before publish rules are invoked synchronously before a message is published and can reject or modify the message. + +| Before publish rules limit | Free | Standard | Pro | Enterprise | +| -------------------------- | ---- | -------- | --- | ---------- | +| **Before publish rule rate (per second)***the maximum rate at which before publish rules can be invoked across your account each second*
| 250 | 250 | 1,000 | Custom | +| **Before publish rule concurrency***the maximum number of before publish rule requests that can be in-flight at any one time*
| 25 | 25 | 100 | Custom | + ## API limits API request limits are the maximum number of [REST API](/docs/api/rest-api) requests, [Control API](/docs/platform/account/control-api) requests and [token requests](/docs/auth/token) that can be made to Ably.