WebMCP

In-browser WebMCP tools that search, read, save, tag and favorite cards in the signed-in Teak web app

Teak’s web app exposes WebMCP tools in browsers that ship the draft document.modelContext API. Unlike the remote MCP server, these tools run inside your signed-in browser session, so an agent helping you in the Teak web app needs no extra sign-in or API key.

Requirements

• A browser with the draft WebMCP API. As of September 2026 this is Chrome’s WebMCP preview behind its experimental flag.
• A signed-in Teak web app session. The tools query your cards with your session and are registered only while you are signed in.

Available tools

The page registers seven tools: six imperative tools and one declarative search form.

limit is 1 to 50 and defaults to 20 wherever a tool takes it, and type accepts text, link, image, video, audio, document, palette, or quote. A CardSummary is { id, type, title, url, excerpt, tags, isFavorited, createdAt, updatedAt }.

Read tools

• teak_search_cards Read-only
  • Input: { q?: string, limit?: number, type?: string, favorited?: boolean }
  • Output: { items: CardSummary[], total: number }. Omit q to list recent cards.
• teak_get_card Read-only
  • Input: { cardId: string }
  • Output: the card’s summary plus content, contentTruncated and notes, or null when the ID does not exist.
• teak_recent_cards Read-only
  • Input: { limit?: number, type?: string }
  • Output: { items: CardSummary[], total: number }, newest first.

Write tools

• teak_create_card Write
  • Input: { content: string, type?: "text" | "quote" | "link", url?: string, notes?: string, tags?: string[] }. type defaults to text.
  • Output: { id, type, url, tags } for the new card. Teak processes it in the background, as it does any card you save.
• teak_update_tags Write
  • Input: { cardId: string, add?: string[], remove?: string[] }. At least one of add or remove must list a tag, and a tag can’t be in both. Tags match ignoring case, and tags you don’t mention are kept.
  • Output: { id, tags } with the card’s tags after the change.
• teak_set_favorite Write
  • Input: { cardId: string, favorited: boolean }
  • Output: { id, isFavorited }.

Declarative search

The search box on the home page is annotated as the declarative teak_search_form tool. Its name stays distinct from the imperative tools above because WebMCP rejects duplicate tool names. The form carries toolautosubmit, so agents can fill in the q field and submit through the same search path as typing without needing a submit button. Unlike the imperative search tool, the declarative form drives the page UI rather than returning structured data.

Try it

On the signed-in web app you can also inspect the registered tools from the DevTools console:

const tools = await document.modelContext.getTools();
tools.map((tool) => tool.name);

Security

• Every tool acts as you, in your signed-in session, on your own cards only.
• Read tools are annotated readOnlyHint and untrustedContentHint, because card content and notes are user-generated. Write tools are annotated consequentialHint.
• Writes are limited to creating a card, changing its tags and setting its favorite. Deleting, archiving, folders and the rest stay on the remote MCP server and the REST API.
• Tool descriptions are static strings. They never interpolate card content, following the spec’s tool-poisoning guidance.
• The tools permission keeps its default allowlist, self, and the web app can’t be framed, so only Teak’s own pages can register and call these tools.

Related

• MCP for external clients such as Claude Code and ChatGPT.
• Teak for AI Agents for choosing between MCP, REST, CLI, and in-browser tools.