Utility types

The inference types that pull tool names, inputs, outputs and metadata out of your server type.

registerTool accumulates the shape of each tool into the type of the server. These utility types read that registry.

Most code does not need them. injectAppHelpers uses them for you. Reach for them when you write a helper of your own, or when you need one tool type in isolation.

Setup

Export the type of your server first.

export function createMcpServer() {
  return new McpServer(/* … */).registerTool(/* … */);
}
export type AppServer = ReturnType<typeof createMcpServer>;

The types

Type	Gives you
`ToolNames<App>`	A union of the registered tool names.
`ToolInput<App, Name>`	The parsed input type of one tool.
`ToolOutput<App, Name>`	The `structuredContent` type of one tool.
`ToolResponseMetadata<App, Name>`	The `_meta` type of one tool response.
`InferTools<App>`	The whole registry.
`AnyToolRegistry`	A constraint for a generic that accepts any server.
`McpServerTypes`	The container that `$types` holds.

import type { ToolInput, ToolNames, ToolOutput } from "ng-mcp-ui/server";

type Names = ToolNames<AppServer>;                    // "create_poll" | "cast_vote"
type PollArgs = ToolInput<AppServer, "create_poll">;  // { question: string }
type PollData = ToolOutput<AppServer, "create_poll">; // { pollId: string; total: number }

Config types

These describe the config objects rather than the registry.

Type	Describes
`ToolConfig`	The config argument of `registerTool`.
`ToolHandler`	The handler argument.
`ToolDef`	One entry in the registry.
`ToolMeta`, `KnownToolMeta`	The `_meta` of a tool.
`ViewConfig`	The `view` field. See CSP.
`ViewCsp`	The `csp` field of a view.
`ViewHostType`	`"apps-sdk"` or `"mcp-app"`.
`ViewName`, `ViewNameRegistry`	The permitted values of `view.component`.
`SecurityScheme`	An entry of `securitySchemes`.
`HandlerContent`	The values that a handler can put in `content`.
`ClientHintsMeta`	The hints on `extra._meta`. See client hints.

ViewNameRegistry

ViewName starts as string. The view generator writes a declaration that adds one key for each view:

declare module "ng-mcp-ui/server" {
  interface ViewNameRegistry {
    poll: true;
  }
}

After the first view exists, ViewName narrows to the union of the registered names. Therefore a typing mistake in view.component becomes a compile error.

Setup

The types

Config types

ViewNameRegistry

Related