changes.ts

// what would be really annoying to do
const result = await gpt4oMini.withConfig({callbacks: [BraintrustCallbackHandler]}).withStructuredOutput( //...

// what would be much better
export const gpt4oMini = new ChatOpenAI({
  model: "gpt-4o-mini",
  callbacks: [BraintrustCallbackHandler],
  ...retryConfig,
});

example.ts

import { AIMessage, HumanMessage } from "@langchain/core/messages";
import { ChatOpenAI } from "@langchain/openai";
import { traceable } from "langsmith/traceable";
import { z } from "zod";
import { AssistantToolCallFailure } from "../errors";
import { immediateRetry } from "../utils";

export const gpt4oMini = new ChatOpenAI({
  model: "gpt-4o-mini",
  ...retryConfig,
});

const NameSchema = z.object({
  name: z
    .string()
    .describe(
      "A short name to identify a web application that's being created according to these instructions"
    ),
  slug: z
    .string()
    .describe(
      "A short, URL-safe slug to identify a web application that's being created according to these instructions"
    ),
});

export const nameForApp = traceable(
  async (prompt: string) => {
    const messages = [
      new HumanMessage(
        `Generate a short, playful name and URL slug to identify a web application that is being created according to the instructions below. Don't name it "silly-<something>", just be whimsical, naming the app things like "manager-3000" or "appy-mc-app-face" or "tool-o-matic" or similar, but more specific to the instructions. Don't just use these jokes. The slug must be under 49 characters long, and the name should be short as well.
# Instructions

${prompt}

Current time: ${new Date().toISOString()}`
      ),
    ];

    return await immediateRetry(async (attempt) => {
      const result = await gpt4oMini
        .withStructuredOutput(NameSchema)
        .withConfig({ cache: false, temperature: 0.8 } as any)
        .invoke(messages, { runName: "nameForApp" });

      if (result.slug.length > 49) {
        messages.push(
          new AIMessage(
            `Here's the generated name and slug:\n\n\`\`\`json\n${JSON.stringify(
              result,
              null,
              2
            )}\n\`\`\``
          ),
          new HumanMessage(
            `The slug is too long. Generate another name and slug that is shorter.`
          )
        );
        throw new AssistantToolCallFailure(
          `Slug is too long after ${attempt} attempt(s)`,
          {
            result,
          }
        );
      }

      return result;
    });
  },
  { name: "nameForApp" }
);