Advanced Topics
TypeScript
Type safety and TypeScript features in the Nuxt MCP module.
Type Safety
The Nuxt MCP module provides full TypeScript support with complete type inference and type safety.
Auto-Imports
All helper functions and types are auto-imported in your server files:
Functions:
defineMcpTool,defineMcpResource,defineMcpPrompt,defineMcpHandlertextResult,jsonResult,errorResult,imageResultcompletable,extractToolNamesuseMcpSession,useMcpServer
Types:
McpToolExtra— extra arguments passed to tool handlers (abort signal, auth info, session ID, metadata)McpPromptExtra— extra arguments passed to prompt handlersMcpResourceExtra— extra arguments passed to resource handlers
import { z } from 'zod'
export default defineMcpTool({
name: 'example',
inputSchema: {
message: z.string(),
},
handler: async ({ message }, extra: McpToolExtra) => {
// message is typed as string
// extra.signal, extra.authInfo, extra.sessionId are available
},
})
You can disable auto-imports entirely with autoImports: false in your configuration and import explicitly from @nuxtjs/mcp-toolkit/server instead.
Type Inference
Tool Input Types
Input types are automatically inferred from your inputSchema:
import { z } from 'zod'
import { defineMcpTool } from '@nuxtjs/mcp-toolkit/server'
export default defineMcpTool({
name: 'example',
inputSchema: {
name: z.string(),
age: z.number(),
email: z.string().email().optional(),
},
handler: async ({ name, age, email }) => {
// name: string
// age: number
// email: string | undefined
},
})
Tool Output Types
Output types are inferred from outputSchema:
import { z } from 'zod'
import { defineMcpTool } from '@nuxtjs/mcp-toolkit/server'
export default defineMcpTool({
name: 'example',
inputSchema: {
value: z.number(),
},
outputSchema: {
result: z.number(),
doubled: z.number(),
},
handler: async ({ value }) => {
const result = value * 2
return {
structuredContent: {
result, // TypeScript knows this is number
doubled: result * 2, // TypeScript knows this is number
},
}
},
})
Prompt Argument Types
Prompt argument types are inferred from inputSchema:
import { defineMcpPrompt } from '@nuxtjs/mcp-toolkit/server'
export default defineMcpPrompt({
name: 'example',
inputSchema: {
text: z.string(),
maxLength: z.string().optional(),
},
handler: async ({ text, maxLength }) => {
// text: string
// maxLength: string | undefined
},
})
Runtime Config Types
Access typed runtime configuration:
server/api/config.ts
export default defineEventHandler((event) => {
const config = useRuntimeConfig(event).mcp
// config is typed with:
// - enabled: boolean
// - route: string
// - browserRedirect: string
// - name: string
// - version: string
// - dir: string
return config
})