TypeScript Types

Typed package surface

The repository README calls out imports such as McpSpec, McpTool, and McpResource from the main package entrypoint.

import type { McpSpec, McpTool, McpResource } from "mcp-schema";

These types give downstream TypeScript projects a shared representation of an MCP server specification without requiring consumers to redefine the document shape themselves.

Example

import type { McpSpec } from "mcp-schema";

const spec: McpSpec = {
  mcpSpec: "0.3.1",
  mcpVersion: "2025-11-25",
  server: {
    name: "weather-server",
    version: "1.0.0",
  },
  description: "Real-time weather data for any city.",
};

What the types cover

Based on the repository documentation, the type surface covers:

• tools
• resources
• resource templates
• prompts
• server capabilities
• transports including stdio, SSE, and streamable HTTP
• schema-oriented structures such as inputSchema, outputSchema, and $defs

The changelog also notes newer type-level additions such as McpIcon and icons fields on multiple surfaces.

When to prefer types

Use TypeScript types when you need to:

• construct MCP specs programmatically
• enforce the expected shape in application code
• share strongly typed spec data between modules
• catch structural mistakes before runtime validation

TypeScript types and JSON Schema are complementary. Types improve the authoring experience in code, while JSON Schema supports validator-based checks for serialized documents.

Practical pattern

A common package-level pattern is to define a typed spec in TypeScript and then validate the serialized result using the schema export during tests or CI. That keeps authoring ergonomic while preserving a validator-backed contract for published or exchanged documents.