> ## Documentation Index
> Fetch the complete documentation index at: https://mcp-b-sync-npm-packages-docs-bf03420.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# @mcp-b/webmcp-types overview

> When to use the WebMCP type package, what it covers, and how it fits under the runtime stack.

`@mcp-b/webmcp-types` is the lowest-level package in the MCP-B stack. It gives you the type contracts for `navigator.modelContext`, schema inference utilities, and the global `Navigator` augmentation without shipping any runtime code.

## When to use this package

* You are authoring a library that wants to type against the WebMCP core surface.
* You want compile-time inference from JSON Schema literals.
* You need `navigator.modelContext` types in TypeScript without choosing a runtime yet.

## When not to use this package

* You need a runtime implementation in the browser. Use [`@mcp-b/webmcp-polyfill`](/packages/webmcp-polyfill/overview) or [`@mcp-b/global`](/packages/global/overview).
* You want prompts, resources, or transport features. Those live higher in the stack.

## Where it sits in the package graph

`@mcp-b/webmcp-types` sits under the runtime packages. `@mcp-b/webmcp-polyfill`, `@mcp-b/webmcp-ts-sdk`, `@mcp-b/global`, `usewebmcp`, and `@mcp-b/react-webmcp` all build on these contracts.

## First step

Install the package as a dev dependency, then choose one activation path from the [reference page](/packages/webmcp-types/reference): `types` in `tsconfig.json`, a triple-slash reference, or a side-effect type import.

## Related pages

<CardGroup cols={2}>
  <Card title="Reference" icon="book-open" href="/packages/webmcp-types/reference">
    Type contracts, schema inference helpers, and activation patterns.
  </Card>

  <Card title="Use schemas and structured output" icon="list-check" href="/how-to/use-schemas-and-structured-output">
    Practical guidance for schema-driven tool inputs and outputs.
  </Card>

  <Card title="Strict core vs MCP-B extensions" icon="diagram-venn" href="/explanation/strict-core-vs-mcp-b-extensions">
    Background on where the standard surface ends.
  </Card>

  <Card title="Choose a runtime" icon="compass" href="/how-to/choose-runtime">
    Pick the runtime layer that pairs with these types.
  </Card>
</CardGroup>