Design-first specification for the Model Context Protocol. Design your MCP server before you write a line of code.

Most MCP servers are built code-first — tools, resources and prompts get shaped during implementation. MCPDS flips the order: a declarative, machine-readable design comes first, code second. One source of truth, validation before implementation, a design both humans and machines can read.

• Read the spec — format, JSON Schema, principles → mcpds
• Try the designer — design a server in a visual editor → mcpdesign.org

• mcpds — specification and schema
• mcp-designer — free visual designer for MCPDS

An open standard. mcpdesign.org