Modality MCP Kit

Schema conversion utilities for MCP tool development with multi-library support. Provides universal JSON Schema conversion via xsschema and AITool-to-FastMCP transformation utilities.

Features

- Universal Schema Conversion: Convert Zod, Valibot, ArkType, Effect, and Sury schemas to JSON Schema via xsschema
- MCP Tool Registration: Transform AITool definitions to FastMCP-compatible format
- Type-Safe: Full TypeScript support with preserved schema types
- Lightweight: Minimal dependencies, focused on MCP tool development

Installation

``bash
npm install modality-mcp-kit


or


bun add modality-mcp-kit
`

Usage

$3

`typescript
import { toJsonSchema } from "modality-mcp-kit";
import { z } from "zod";

const userSchema = z.object({
id: z.string(),
name: z.string(),
age: z.number(),
});

const jsonSchema = toJsonSchema(userSchema);
`

$3

`typescript
import { setupAITools, ModalityFastMCP } from "modality-mcp-kit";
import { z } from "zod";

const mcp = new ModalityFastMCP();

const aiTools = {
getUserById: {
name: "get_user",
description: "Get user by ID",
inputSchema: z.object({ id: z.string() }),
execute: async (args) => {
return { id: args.id, name: "John" };
},
},
};

// Registers tools with MCP server and transforms inputSchema → parameters
setupAITools(aiTools, mcp);
`

API

$3

Converts any supported schema (Zod, Valibot, ArkType, Effect, Sury) to JSON Schema.

$3

Transforms AITool definitions to FastMCP format:
- Converts inputSchema to parameters
- Uses key as name if not specified
- Registers with optional MCP server

$3

FastMCP-compatible implementation with addTool() and getTools()` methods.

Repository

- GitHub: https://github.com/react-atomic/modality
- NPM: https://www.npmjs.com/package/modality-mcp-kit

License

MIT