registerMentions

This is an OpenAI MCP extension, not part of MCP or MCP Apps. Only ChatGPT supports it, and other hosts ignore it.

By default, users can only at-mention your app as a whole. registerMentions lets them mention individual items, such as parts, files or people: when the user types @ and your app, ChatGPT calls your handler with the text typed so far and lists the items it returns. ChatGPT desktop only.

Example

A parts catalog lets the user mention a part by name.

server.registerMentions({
  name: "search_parts",
  handler: async ({ query }) => ({
    items: (await findParts(query)).map((part) => ({
      type: "resource_link",
      uri: `parts://${part.id}`,
      name: part.name,
    })),
  }),
});

Parameters

`config`

type OpenAIMentionsConfig = {
  name: string;
  description?: string;
  handler: (
    params: { query: string },
    extra: ToolHandlerExtra,
  ) => { items: ResourceLink[] } | Promise<{ items: ResourceLink[] }>;
};

Field	Purpose
`name`	Name of the tool ChatGPT calls for each search.
`description`	Tool description. Defaults to a generic one, since the model never sees this tool.
`handler`	Receives the typed text as `query`, which may be empty, and returns the matching items as MCP resource links. `extra` is the same as in a `registerTool` handler.

How it works

Skybridge registers a tool named name that takes { query: string } and returns { items } as structuredContent. Its _meta carries "openai/extensions": { "mentions/search": {} }, which tells ChatGPT it serves mentions, and ui.visibility: ["app"], which hides it from the model. It requires sign-in like any other tool on a server with oauth. Returns the server, so calls chain.

Serve the mentioned items

When the user picks an item, its resource link goes into the message, so the model gets the uri rather than the item itself. Serve those URIs as MCP resources so the host can read them:

import { ResourceTemplate } from "skybridge/server";

server.registerResource(
  "part",
  new ResourceTemplate("parts://{id}", { list: undefined }),
  { mimeType: "application/json" },
  async (uri, { id }) => ({
    contents: [{ uri: uri.href, text: JSON.stringify(await getPart(String(id))) }],
  }),
);

registerTool

McpServer

Every method of the server

Server

Auth

Identity Providers

Hooks

Utilities

Types

Low-level

Example

Parameters

`config`

How it works

Serve the mentioned items

registerTool

McpServer

​Example

​Parameters

​config

​How it works

​Serve the mentioned items

registerTool

McpServer

Example

Parameters

`config`

How it works

Serve the mentioned items