> ## Documentation Index
> Fetch the complete documentation index at: https://langchain-5e9cc07a-preview-ramonn-1789138246-3410f5f.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# LangGraph v1 migration guide

<Prompt description="Migrate a codebase to LangGraph v1." icon="arrow-right" actions={["copy"]}>
  Migrate this codebase to LangGraph v1 (requires `@langchain/langgraph` and `@langchain/core` at v1, plus `langchain` at v1 when migrating from `createReactAgent`, and Node.js 22+).

  Key changes:

  1. **Upgrade packages**: install `@langchain/langgraph@latest` and `@langchain/core@latest`. If you use `createReactAgent`, also install `langchain@latest`.
  2. **`createReactAgent` → `createAgent`**: replace `import { createReactAgent } from "@langchain/langgraph/prebuilts"` with `import { createAgent } from "langchain"`. Rename `prompt` to `systemPrompt`.
  3. **Typed interrupts**: define interrupt types at graph construction via an `interrupts` config on `StateGraph`.
  4. **`toLangGraphEventStream` removed**: use `graph.stream` with an `encoding` option (for example `"text/event-stream"`) instead of `toLangGraphEventStream` / `toLangGraphEventStreamResponse`.
  5. **`useStream`**: supports custom transports.
  6. **Build outputs**: do not import from package `dist/` paths; use the public module exports.

  Search the codebase for `createReactAgent`, `toLangGraphEventStream`, `toLangGraphEventStreamResponse`, and `@langchain/langgraph/prebuilts`, and apply the necessary changes. Flag anything that cannot be migrated automatically.
</Prompt>

This guide outlines changes in LangGraph v1 and how to migrate from previous versions. For a high-level overview of what's new, see the [release notes](/oss/javascript/releases/langgraph-v1).

To upgrade,

<CodeGroup>
  ```bash npm theme={null}
  npm install @langchain/langgraph@latest @langchain/core@latest
  ```

  ```bash pnpm theme={null}
  pnpm add @langchain/langgraph@latest @langchain/core@latest
  ```

  ```bash yarn theme={null}
  yarn add @langchain/langgraph@latest @langchain/core@latest
  ```

  ```bash bun theme={null}
  bun add @langchain/langgraph@latest @langchain/core@latest
  ```
</CodeGroup>

## Summary of changes

| Area                             | What changed                                               |
| -------------------------------- | ---------------------------------------------------------- |
| React prebuilt                   | `createReactAgent` deprecated; use LangChain `createAgent` |
| Interrupts                       | Typed interrupts supported via `interrupts` config         |
| `toLangGraphEventStream` removed | Use `graph.stream` with the desired `encoding` format      |
| `useStream`                      | Supports custom transports                                 |

***

## Deprecation: `createReactAgent` → `createAgent`

LangGraph v1 deprecates the `createReactAgent` prebuilt. Use LangChain's `createAgent`, which runs on LangGraph and adds a flexible middleware system.

See the LangChain v1 docs for details:

* [Release notes](/oss/javascript/releases/langchain-v1#createagent)
* [Migration guide](/oss/javascript/migrate/langchain-v1#createagent)

<CodeGroup>
  ```typescript v1 (new) theme={null}
  import { createAgent } from "langchain";

  const agent = createAgent({
    model,
    tools,
    systemPrompt: "You are a helpful assistant.", // [!code highlight]
  });
  ```

  ```typescript v0 (old) theme={null}
  import { createReactAgent } from "@langchain/langgraph/prebuilts";

  const agent = createReactAgent({
    model,
    tools,
    prompt: "You are a helpful assistant.", // [!code highlight]
  });
  ```
</CodeGroup>

***

## Typed interrupts

You can now define interrupt types at graph construction to strictly type the values passed to and received from interrupts.

<CodeGroup>
  ```typescript v1 (new) theme={null}
  import { StateGraph, interrupt } from "@langchain/langgraph";
  import * as z from "zod";

  const State = z.object({ foo: z.string() });

  const graphConfig = {
    interrupts: {
      approve: interrupt<{ reason: string }, { messages: string[] }>(),
    },
  }

  const graph = new StateGraph(State, graphConfig)
    .addNode("node", async (state, runtime) => {
      const value = runtime.interrupt.approve({ reason: "review" }); // [!code highlight]
      return { foo: value };
    })
    .compile();
  ```

  ```typescript v0 (old) theme={null}
  import { StateGraph } from "@langchain/langgraph";

  const graph = new StateGraph(State)
    .addNode("node", async (state, runtime) => {
      const value = runtime.interrupt.approve({ reason: "review" }); // [!code highlight]
      return state;
    })
    .compile();
  ```
</CodeGroup>

See [Interrupts](/oss/javascript/langgraph/interrupts) to learn more.

***

## Event stream encoding

The low-level `toLangGraphEventStream` helper is removed. Streaming responses are handled by the SDK; when using low-level clients, select the wire format via an `encoding` option passed to `graph.stream`.

<CodeGroup>
  ```typescript v1 (new) theme={null}
  const stream = await graph.stream(input, {
    encoding: "text/event-stream",
    streamMode: ["values", "messages"],
  });

  return new Response(stream, {
    headers: { "Content-Type": "text/event-stream" }, // [!code highlight]
  });
  ```

  ```typescript v0 (old) theme={null}
  return toLangGraphEventStreamResponse({
    stream: graph.streamEvents(input, {
      version: "v2",
      streamMode: ["values", "messages"],
    }),
  });
  ```
</CodeGroup>

***

## Breaking changes

### Dropped Node 18 support

All LangGraph packages now require **Node.js 22 or higher**. Node.js 18 reached [end of life](https://nodejs.org/en/about/releases/) in March 2025.

### New build outputs

Builds for all langgraph packages now use a bundler based approach instead of using raw typescript outputs. If you were importing files from the `dist/` directory (which is not recommended), you will need to update your imports to use the new module system.

***

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