Amazon Q Business Custom Plugin Timeout Limit

Consider below as workarounds:

• Async Processing: Have your plugin trigger the long-running task and return a task ID immediately. Then, use a separate query to check the status or retrieve the result later.
• Optimize API Performance: If possible, reduce the processing time of your API to fit within a 30–60 second window.
• Use Event-Driven Architecture: Consider using AWS services like SQS or Lambda to queue and process tasks asynchronously, then notify the user when the result is ready.

Based on the available information, there isn't specific documentation about the timeout limit for Amazon Q Business Custom Plugin when calling custom APIs.

For Amazon Q Business, there is information about the chatSync API having a default limit of 5 maximum queries per second (QPS) per index when using the UI, and this limit is adjustable by contacting AWS Support. However, this refers to throttling limits rather than timeout duration.

For API Gateway, which might be relevant if you're using it as part of your integration, the integration timeout can be set between 50 milliseconds and 29 seconds by default. For Regional APIs and private APIs, this timeout can be increased beyond 29 seconds, though this might require a reduction in your account-level throttle quota limit.

If you're planning to integrate with a custom API that could run for several minutes, I recommend reaching out to AWS Support directly to understand the specific timeout limitations for Amazon Q Business Custom Plugin and to discuss potential solutions for your use case.
Sources
API getaway timeout limit | AWS re:Post
API limits and cost for Q business chatSync API | AWS re:Post
Integration - Amazon API Gateway