docs/build/snippets/python/code-samples/hitl-basic-config-js.mdx

```ts
import { tool } from "langchain";
import { createDeepAgent } from "deepagents";
import { MemorySaver } from "@langchain/langgraph";
import { z } from "zod";

const removeFile = tool(
  async ({ path }: { path: string }) => {
    return `Deleted ${path}`;
  },
  {
    name: "remove_file",
    description: "Delete a file from the filesystem.",
    schema: z.object({
      path: z.string(),
    }),
  },
);

const fetchFile = tool(
  async ({ path }: { path: string }) => {
    return `Contents of ${path}`;
  },
  {
    name: "fetch_file",
    description: "Read a file from the filesystem.",
    schema: z.object({
      path: z.string(),
    }),
  },
);

const notifyEmail = tool(
  async ({
    to,
    subject,
    body,
  }: {
    to: string;
    subject: string;
    body: string;
  }) => {
    return `Sent email to ${to}`;
  },
  {
    name: "notify_email",
    description: "Send an email.",
    schema: z.object({
      to: z.string(),
      subject: z.string(),
      body: z.string(),
    }),
  },
);

// Checkpointer is REQUIRED for human-in-the-loop
const checkpointer = new MemorySaver();

const agent = createDeepAgent({
  model: "google_genai:gemini-3.6-flash",
  tools: [removeFile, fetchFile, notifyEmail],
  interruptOn: {
    remove_file: true, // Default: approve, edit, reject, respond
    fetch_file: false, // No interrupts needed
    notify_email: { allowedDecisions: ["approve", "reject"] }, // No editing
  },
  checkpointer, // Required!
});
```