> ## Documentation Index
> Fetch the complete documentation index at: https://sunpeak.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# MCP Apps updateModelContext - Update Host Model Context

> Update the host's model context with app state. Provide structured or unstructured data that the model can access in future turns without triggering an immediate response.

<Badge color="green">MCP Apps SDK</Badge>

```ts theme={null}
import { App } from "@modelcontextprotocol/ext-apps";
```

## Overview

`updateModelContext` pushes app state into the host's model context. This data becomes available to the model on future turns without triggering an immediate response -- unlike `sendMessage`, which injects a message into the conversation and may prompt the model to reply.

Each call to `updateModelContext` **overwrites** any previously set context. To clear the context, call it with empty content.

This is useful for keeping the model informed about what the user is viewing or doing in the app, such as the current page, selected items, or filter state.

## Signature

```ts theme={null}
async updateModelContext(
  params: {
    content?: ContentBlock[];
    structuredContent?: Record<string, unknown>;
  },
  options?: RequestOptions,
): Promise<void>
```

## Parameters

<ResponseField name="params" type="object" required>
  The context update parameters. Provide at least one of `content` or `structuredContent`.

  <ResponseField name="content" type="ContentBlock[]">
    Array of content blocks (text, images, etc.) to set as the model context. The model can read these on subsequent turns.
  </ResponseField>

  <ResponseField name="structuredContent" type="Record<string, unknown>">
    Structured data to set as the model context. Useful for passing typed objects, configuration, or state that the model can reference.
  </ResponseField>
</ResponseField>

<ResponseField name="options" type="RequestOptions">
  Optional request configuration.

  <ResponseField name="signal" type="AbortSignal">
    An `AbortSignal` to cancel the request.
  </ResponseField>
</ResponseField>

## Returns

Resolves with `void` on success. Throws on transport or protocol failure.

## Usage

### Set text context

```ts theme={null}
await app.updateModelContext({
  content: [{
    type: "text",
    text: `User is viewing page ${currentPage} of ${totalPages}`,
  }],
});
```

### Set structured context

```ts theme={null}
await app.updateModelContext({
  structuredContent: {
    selectedItems: ["item-1", "item-5"],
    filters: { category: "electronics", priceRange: [100, 500] },
  },
});
```

### Clear previous context

```ts theme={null}
await app.updateModelContext({ content: [] });
```

<Tip>
  For large follow-up messages, offload data to `updateModelContext` first, then send a brief trigger via `sendMessage`:

  ```ts theme={null}
  await app.updateModelContext({
    content: [{ type: "text", text: fullTranscript }],
  });
  await app.sendMessage({
    role: "user",
    content: [{ type: "text", text: "Summarize the key points" }],
  });
  ```
</Tip>

## Related

* [Requests overview](/mcp-apps/app/requests) -- all available View-to-host request methods
* [`useUpdateModelContext`](/app-framework/hooks/use-update-model-context) -- sunpeak React convenience hook
* [sendMessage](/mcp-apps/app/requests/send-message) -- send a message that appears in the conversation