Creating Your Own Loop

Now that we've gone full workflow, why don't we pull it back a little bit and inject some agentic behavior into our workflow. Instead of just taking a linear path - creating a first draft, evaluating it, then creating another draft - let's run that loop a specific number of times to see if we can get a better output.

The appeal of this approach is flexibility. That loop count could be increased over time or tuned to configure our system remotely. You might even give high-paying customers a better experience than lower-paying customers by increasing their loop iterations.

The code for this lives inside our POST route. In the problem code, we need to modify the execute function to implement our loop:

export const POST = async (req: Request): Promise<Response> => {
  const body: { messages: MyMessage[] } = await req.json();
  const { messages } = body;

Instead of the existing linear workflow with separate sections for first draft, feedback, and final message, we'll create a while loop that repeats the process a specified number of times.

We'll need to maintain state between iterations by tracking:

• Which step we're on
• The most recent draft
• The most recent feedback

Once the loop is done, we'll use the final draft as our response, streaming it as a text part rather than a custom data part. Check out the reference material to see how to do this.

Make sure you lock down the stop condition of your while loop - paid systems with potential infinite loops can be scary! Always ensure your loop has a clear exit condition.

Good luck, and I'll see you in the solution.

Steps To Complete

• Initialize variables at the beginning of the execute function: step (starting at 0), mostRecentDraft (empty string), and mostRecentFeedback (empty string)

• Create a while loop that continues until step < 2 (or another number of your choosing)

• Increment the step variable at the end of each loop iteration

• Inside the loop, implement the slack message writing logic:

  • Stream the draft to the client using writer.write
  • Store the draft in mostRecentDraft

• Still inside the loop, implement the evaluation logic:

  • Stream the feedback to the client
  • Store the feedback in mostRecentFeedback

• After the loop completes, stream the final text as a text part:

  • Create a text-start part
  • Create a text-delta part with the final draft
  • Create a text-end part

• Test your implementation by running the local dev server and checking if the Slack message generation shows multiple drafts and feedback cycles