Add comprehensive schema validation and type system to MCPSchema gem - also add the gem
Note
I know it looks like a lot of code. But, according to coverage, only 443 lines are actually executable code. The rest is documentation, comments, tests and gem boilerplate.
What does this MR do and why?
Creates MCPSchema gem and adds comprehensive schema validation and type system to it
This release (v1.0.0) introduces a complete type system with JSON Schema validation for the MCPGraphQL DSL, including:
- Boolean, String, Number, and Enum schema types with validation
- Collections - Array & Object with both parameter and block-based syntax
- Property management helpers for schema composition
- Global configuration system for MCP tool settings
- Comprehensive test coverage for all new components
- Integration tests for complete schema definition workflows
The gem now provides robust input validation and type safety for Model Context Protocol tool definitions in GitLab's MCP server.
References
Usage
class ComprehensiveTool
include MCPSchema::DSL::Base
mcp_tool_name :comprehensive_tool
mcp_description "A tool demonstrating all schema types"
mcp_input_schema do
# String types
String :name, required: true, description: "User name"
URI :website, description: "Website URL"
Email :contact, required: true, description: "Contact email"
Date :birthday, description: "Birth date"
DateTime :created_at, required: true, description: "Creation timestamp"
# Number types
Number :score, minimum: 0, maximum: 100, description: "Score value"
Integer :count, required: true, minimum: 1, description: "Item count"
# Boolean types
Boolean :active, required: true, description: "Whether item is active"
Boolean :featured, description: "Whether item is featured", default: false
# Enum types
Enum :status, enum: %w[draft published archived], required: true, description: "Publication status"
Enum :priority, enum: %w[low medium high], enum_names: %w[Low Medium High],
description: "Task priority"
# Array types
Array :tags, items: { type: "string" }, required: true, description: "List of tags"
Array :matrix, description: "2D matrix of numbers" do
Array :row do
Number :value
end
end
# Object types
Object :project, required: "true", description: "Project" do
String :title, required: true, description: "Project title"
URI :repository, description: "Git repository URL"
Date :start_date, required: true
Date :end_date
Boolean :completed, default: false
end
end
mcp_output_schema do
String :result_id, required: true, description: "Unique result identifier"
Boolean :success, required: true, description: "Whether operation succeeded"
Enum :result_type, enum: %w[created updated deleted], description: "Type of operation performed"
String :message, description: "Human readable result message"
end
mcp_annotations do
audience "user", "assistant"
last_modified "2023-12-01T10:30:00Z"
priority 0.9
end
end{
"name": "comprehensive_tool",
"description": "A tool demonstrating all schema types",
"inputSchema": {
"type": "object",
"properties": {
"name": {
"type": "string",
"description": "User name"
},
"website": {
"type": "string",
"format": "uri",
"description": "Website URL"
},
"contact": {
"type": "string",
"format": "email",
"description": "Contact email"
},
"birthday": {
"type": "string",
"format": "date",
"description": "Birth date"
},
"created_at": {
"type": "string",
"format": "date-time",
"description": "Creation timestamp"
},
"score": {
"type": "number",
"minimum": 0,
"maximum": 100,
"description": "Score value"
},
"count": {
"type": "integer",
"minimum": 1,
"description": "Item count"
},
"active": {
"type": "boolean",
"description": "Whether item is active"
},
"featured": {
"type": "boolean",
"description": "Whether item is featured",
"default": false
},
"status": {
"type": "string",
"enum": ["draft", "published", "archived"],
"description": "Publication status"
},
"priority": {
"type": "string",
"enum": ["low", "medium", "high"],
"enumNames": ["Low", "Medium", "High"],
"description": "Task priority"
},
"tags": {
"type": "array",
"items": {
"type": "string"
},
"description": "List of tags"
},
"matrix": {
"type": "array",
"items": {
"type": "array",
"items": {
"type": "number"
}
},
"description": "2D matrix of numbers"
},
"project": {
"type": "object",
"properties": {
"title": {
"type": "string",
"description": "Project title"
},
"repository": {
"type": "string",
"format": "uri",
"description": "Git repository URL"
},
"start_date": {
"type": "string",
"format": "date"
},
"end_date": {
"type": "string",
"format": "date"
},
"completed": {
"type": "boolean",
"default": false
}
},
"required": ["title", "start_date"],
"description": "Project"
}
},
"required": ["name", "contact", "created_at", "count", "active", "status", "tags", "project"]
},
"outputSchema": {
"type": "object",
"properties": {
"result_id": {
"type": "string",
"description": "Unique result identifier"
},
"success": {
"type": "boolean",
"description": "Whether operation succeeded"
},
"result_type": {
"type": "string",
"enum": ["created", "updated", "deleted"],
"description": "Type of operation performed"
},
"message": {
"type": "string",
"description": "Human readable result message"
}
},
"required": ["result_id", "success"]
},
"annotations": {
"audience": ["user", "assistant"],
"lastModified": "2023-12-01T10:30:00Z",
"priority": 0.9
}
}How to set up and validate locally
It is a gem build as part of the monolith. No need for any extra setup except fro bundle install and integration if we decide to go this direction.
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Edited by Armin Pašalić