adapters | Dosu

Adapters customize runtime behavior. They can be passed as options to useLocalRuntime or useRemoteThreadListRuntime.

createFileStorageAdapter#

A RemoteThreadListAdapter that persists threads and messages to a local directory. See Custom Backend → Option 2 for usage.

import { createFileStorageAdapter } from "@assistant-ui/react-ink";

const adapter = createFileStorageAdapter({
  dir: "/path/to/threads",
});

Attachment adapters#

SimpleTextAttachmentAdapter and SimpleImageAttachmentAdapter work the same in the terminal as on web and React Native. Text contents are sent to the model wrapped in <attachment name="..."> tags. Ampersands, double quotes, and angle brackets are escaped in the quoted filename; the attachment body remains raw text. Images are sent as base64 data URLs.

import {
  CompositeAttachmentAdapter,
  SimpleImageAttachmentAdapter,
  SimpleTextAttachmentAdapter,
  useLocalRuntime,
} from "@assistant-ui/react-ink";

const runtime = useLocalRuntime(chatModelAdapter, {
  adapters: {
    attachments: new CompositeAttachmentAdapter([
      new SimpleTextAttachmentAdapter(),
      new SimpleImageAttachmentAdapter(),
    ]),
  },
});

TitleGenerationAdapter#

Produces a thread title from a thread's messages. Pass one as the titleGenerator option to createFileStorageAdapter, or call it from a custom RemoteThreadListAdapter.

type TitleGenerationAdapter = {
  generateTitle(messages: readonly ThreadMessage[]): Promise<string>;
};

createSimpleTitleAdapter is the built-in implementation; it derives the title from the first user message, truncated to 50 characters.

import {
  createFileStorageAdapter,
  createSimpleTitleAdapter,
} from "@assistant-ui/react-ink";

const adapter = createFileStorageAdapter({
  dir: "/path/to/threads",
  titleGenerator: createSimpleTitleAdapter(),
});

RemoteThreadListAdapter#

Title generation is configured via the generateTitle method on RemoteThreadListAdapter. See the Custom Backend page for a full example.

import type { RemoteThreadListAdapter } from "@assistant-ui/react-ink";
import { createAssistantStream } from "assistant-stream";

const myAdapter: RemoteThreadListAdapter = {
  // ... other methods ...

  async generateTitle(remoteId, unstable_messages) {
    return createAssistantStream(async (controller) => {
      const res = await fetch(`/api/threads/${remoteId}/title`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ messages: unstable_messages }),
      });
      const { title } = await res.json();
      controller.appendText(title);
    });
  },
};

Which option to choose?#

	ChatModelAdapter + `useLocalRuntime`	RemoteThreadListAdapter + `useRemoteThreadListRuntime`
Thread storage	In-memory	Your backend
Message storage	In-memory	In-memory (can add history adapter for server-side)
Cross-session persistence	No	Yes
Setup complexity	Minimal	Moderate
Best for	CLI tools, demos, prototypes	Production apps with persistence