ToolRuntime

import { tool, type ToolRuntime } from "@langchain/core/tools";
import { z } from "zod";

const stateSchema = z.object({
  messages: z.array(z.any()),
  userId: z.string().optional(),
});

const greet = tool(
  async ({ name }, runtime: ToolRuntime<typeof stateSchema>) => {
    // Access state
    const messages = runtime.state.messages;

    // Access tool_call_id
    console.log(`Tool call ID: ${runtime.toolCallId}`);

    // Access config
    console.log(`Run ID: ${runtime.config.runId}`);

    // Access runtime context
    const userId = runtime.context?.userId;

    // Access store
    await runtime.store?.mset([["key", "value"]]);

    // Stream output
    runtime.writer?.("Processing...");

    return `Hello! User ID: ${runtime.state.userId || "unknown"} ${name}`;
  },
  {
    name: "greet",
    description: "Use this to greet the user once you found their info.",
    schema: z.object({ name: z.string() }),
    stateSchema,
  }
);

const agent = createAgent({
  model,
  tools: [greet],
  stateSchema,
  contextSchema,
});