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

# WebMCP declarative API

> Short reference and upstream links for the evolving HTML form integration.

Declarative WebMCP maps annotated HTML forms to tools while keeping the form
visible to the user. Its proposal and implementation details remain split
across upstream sources.

## Upstream sources

| Need | Source |
| - | - |
| Current proposal design | [Declarative API explainer](https://github.com/webmachinelearning/webmcp/blob/main/declarative-api-explainer.md) |
| Proposal integration status | [Declarative section of the Community Group draft](https://webmachinelearning.github.io/webmcp/#declarative-webmcp) |
| Chrome attributes, events, and submission behavior | [Chrome declarative API](https://developer.chrome.com/docs/ai/webmcp/declarative-api) |
| Executable compatibility cases | [Declarative Web Platform Tests](https://wpt.fyi/results/webmcp/declarative) |
| Tool and form design guidance | [Chrome WebMCP best practices](https://developer.chrome.com/docs/ai/webmcp/best-practices) |

The Community Group draft does not yet contain a complete normative
declarative definition. Treat the explainer as proposal design and Chrome's
documentation as Chrome implementation behavior.

## MCP-B coverage

[`@mcp-b/webmcp-polyfill`](/packages/webmcp-polyfill/reference#declarative-tools)
temporarily adds declarative tools alongside the vendored upstream core until
upstream supports them. Existing native `SubmitEvent` hooks are preserved. [`@mcp-b/react-webmcp`](/packages/react-webmcp/reference#declarative-form-attributes)
provides JSX declarations for the supported form attributes; it does not add a
separate declarative runtime.

For imperative JavaScript tools, use the [WebMCP API quick
reference](/reference/webmcp/standard-api).


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