How to Build a Real-Time Slack Agent Using Bun, Hono, and Event-Driven Orchestration

Building Slack bots is fun until you try to integrate heavy AI pipelines.

If you are building an AI agent that runs sequential steps (e.g., Planning -> Web Searching -> Code Execution -> Summarization), the process is going to take 10 to 20 seconds.

Here is the problem: Slack slash commands MUST receive an HTTP response within 3,000 milliseconds. If your server takes 3.1 seconds to respond, the user gets a generic "operation_timeout" error.

In this post, I will share the exact architecture we used to bypass this timeout for our open-source agent platform, Saar Nexus, using Bun, Hono, and event-driven webhook streaming.

The Timeout Architecture