Class: Mcp::Auth::ScopeRegistry

Inherits:
Object
  • Object
show all
Defined in:
lib/mcp/auth/scope_registry.rb

Overview

ScopeRegistry manages OAuth scopes for MCP Auth

By default, provides basic MCP scopes (mcp:read, mcp:write) automatically. Applications can register custom scopes which will replace the defaults.

Example:

Mcp::Auth::ScopeRegistry.register_scope('mcp:tools',
  name: 'Tool Execution',
  description: 'Execute tools and actions',
  required: false
)

Class Method Summary collapse

Class Method Details

.available_scopes ⇒ Object

All available scopes If no scopes are registered, returns basic MCP scopes for backwards compatibility



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# File 'lib/mcp/auth/scope_registry.rb', line 25

def available_scopes
  return custom_scopes unless custom_scopes.empty?

  # Fallback: If no scopes registered, use basic MCP scopes
  # This ensures backwards compatibility
  {
    'mcp:read' => {
      name: 'Read Access',
      description: 'Read your data and resources',
      required: true
    },
    'mcp:write' => {
      name: 'Write Access',
      description: 'Create and modify data on your behalf',
      required: false
    }
  }
end

.clear_scopes! ⇒ Object

Clear all registered scopes (useful for testing)



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# File 'lib/mcp/auth/scope_registry.rb', line 54

def clear_scopes!
  @custom_scopes = {}
end

.custom_scopes ⇒ Object

Custom scopes registered by the application



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# File 'lib/mcp/auth/scope_registry.rb', line 19

def custom_scopes
  @custom_scopes ||= {}
end

.default_scope_string ⇒ Object

Get default scopes string for a client



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# File 'lib/mcp/auth/scope_registry.rb', line 106

def default_scope_string
  # Return all registered scopes, or empty string if none
  available_scopes.keys.join(' ')
end

.format_for_display(requested_scopes) ⇒ Object

Format scopes for consent screen display



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# File 'lib/mcp/auth/scope_registry.rb', line 91

def format_for_display(requested_scopes)
  scopes = requested_scopes.is_a?(String) ? requested_scopes.split : requested_scopes

  scopes.map do |scope|
    metadata = scope_metadata(scope)
    {
      key: scope,
      name: metadata[:name],
      description: metadata[:description],
      required: metadata[:required]
    }
  end
end

.register_scope(scope_key, name:, description:, required: false) ⇒ Object

Register a custom scope



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# File 'lib/mcp/auth/scope_registry.rb', line 45

def register_scope(scope_key, name:, description:, required: false)
  custom_scopes[scope_key.to_s] = {
    name: name,
    description: description,
    required: required
  }
end

.scope_exists?(scope) ⇒ Boolean

Check if a scope exists

Returns:

  • (Boolean) 


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# File 'lib/mcp/auth/scope_registry.rb', line 59

def scope_exists?(scope)
  available_scopes.key?(scope.to_s)
end

.scope_metadata(scope) ⇒ Object

Get scope metadata



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# File 'lib/mcp/auth/scope_registry.rb', line 64

def scope_metadata(scope)
  available_scopes[scope.to_s] || {
    name: scope,
    description: scope,
    required: false
  }
end

.validate_scopes(requested_scopes) ⇒ Object

Validate and filter requested scopes



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# File 'lib/mcp/auth/scope_registry.rb', line 73

def validate_scopes(requested_scopes)
  # If no scopes requested, return all required scopes
  if requested_scopes.blank?
    return available_scopes.select { |_, meta| meta[:required] }.keys
  end

  scopes = requested_scopes.is_a?(String) ? requested_scopes.split : requested_scopes

  # Filter to only valid registered scopes
  valid_scopes = scopes.select { |scope| scope_exists?(scope) }

  # Always include required scopes
  required_scopes = available_scopes.select { |_, meta| meta[:required] }.keys

  (valid_scopes + required_scopes).uniq
end