Module: MailCatcher::Integrations::MCPTools

Extended by:
MCPTools
Included in:
MCPTools
Defined in:
lib/mail_catcher/integrations/mcp_tools.rb

Overview

MCP Tool Registry Defines the set of tools available to Claude through MCP and Claude Plugins Each tool maps to existing Mail module methods

Constant Summary collapse

TOOLS =

Tool definitions for MCP and Plugin

{
  search_messages: {
    description: "Search through caught emails with flexible filtering",
    input_schema: {
      type: "object",
      properties: {
        query: {
          type: "string",
          description: "Search term (searches subject, sender, recipients, body)"
        },
        limit: {
          type: "integer",
          description: "Maximum number of results to return",
          default: 5
        },
        has_attachments: {
          type: "boolean",
          description: "Filter to only messages with attachments",
          default: false
        },
        from_date: {
          type: "string",
          description: "ISO 8601 datetime to search from (e.g., '2024-01-12T00:00:00Z')",
          default: nil
        },
        to_date: {
          type: "string",
          description: "ISO 8601 datetime to search until (e.g., '2024-01-12T23:59:59Z')",
          default: nil
        }
      },
      required: ["query"]
    }
  },

  get_latest_message_for: {
    description: "Get the latest email received by a specific recipient",
    input_schema: {
      type: "object",
      properties: {
        recipient: {
          type: "string",
          description: "Email address to match in recipients"
        },
        subject_contains: {
          type: "string",
          description: "Optional: Only return message if subject contains this text",
          default: nil
        }
      },
      required: ["recipient"]
    }
  },

  extract_token_or_link: {
    description: "Extract authentication tokens or links from a message",
    input_schema: {
      type: "object",
      properties: {
        message_id: {
          type: "integer",
          description: "ID of the message to extract from"
        },
        kind: {
          type: "string",
          enum: ["magic_link", "otp", "reset_token", "all"],
          description: "Type of token/link to extract"
        }
      },
      required: ["message_id", "kind"]
    }
  },

  get_parsed_auth_info: {
    description: "Get structured authentication information from a message",
    input_schema: {
      type: "object",
      properties: {
        message_id: {
          type: "integer",
          description: "ID of the message to parse"
        }
      },
      required: ["message_id"]
    }
  },

  get_message_preview_html: {
    description: "Get HTML preview of a message (responsive for mobile if requested)",
    input_schema: {
      type: "object",
      properties: {
        message_id: {
          type: "integer",
          description: "ID of the message to preview"
        },
        mobile: {
          type: "boolean",
          description: "Return mobile-optimized preview",
          default: false
        }
      },
      required: ["message_id"]
    }
  },

  delete_message: {
    description: "Delete a specific message by ID",
    input_schema: {
      type: "object",
      properties: {
        message_id: {
          type: "integer",
          description: "ID of the message to delete"
        }
      },
      required: ["message_id"]
    }
  },

  clear_messages: {
    description: "Delete all caught messages (destructive operation)",
    input_schema: {
      type: "object",
      properties: {}
    }
  }
}.freeze

Instance Method Summary collapse

Instance Method Details

#all_tools ⇒ Object

Get all tools



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# File 'lib/mail_catcher/integrations/mcp_tools.rb', line 154

def all_tools
  TOOLS
end

#call_clear_messages(input) ⇒ Object 



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# File 'lib/mail_catcher/integrations/mcp_tools.rb', line 331

def call_clear_messages(input)
  Mail.delete!
  {
    cleared: true,
    message: "All messages have been deleted"
  }
end

#call_delete_message(input) ⇒ Object 



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# File 'lib/mail_catcher/integrations/mcp_tools.rb', line 319

def call_delete_message(input)
  message_id = (input["message_id"] || input[:message_id]).to_i

  return { error: "Message not found" } unless Mail.message(message_id)

  Mail.delete_message!(message_id)
  {
    deleted: true,
    message_id: message_id
  }
end

#call_extract_token_or_link(input) ⇒ Object 



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# File 'lib/mail_catcher/integrations/mcp_tools.rb', line 244

def call_extract_token_or_link(input)
  message_id = (input["message_id"] || input[:message_id]).to_i
  kind = input["kind"] || input[:kind]

  return { error: "Message not found" } unless Mail.message(message_id)

  # Map kind parameter to Mail.extract_tokens type
  type_map = {
    "magic_link" => "link",
    "otp" => "otp",
    "reset_token" => "token",
    "all" => "all"
  }

  type = type_map[kind]
  return { error: "Invalid kind: #{kind}" } unless type

  if kind == "all"
    # Extract all types
    {
      magic_links: Mail.extract_tokens(message_id, type: 'link'),
      otps: Mail.extract_tokens(message_id, type: 'otp'),
      reset_tokens: Mail.extract_tokens(message_id, type: 'token')
    }
  else
    {
      extracted: Mail.extract_tokens(message_id, type: type)
    }
  end
end

#call_get_latest_message_for(input) ⇒ Object 



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# File 'lib/mail_catcher/integrations/mcp_tools.rb', line 211

def call_get_latest_message_for(input)
  recipient = input["recipient"] || input[:recipient]
  subject_contains = input["subject_contains"] || input[:subject_contains]

  # Search all messages to find matching recipient
  all_messages = Mail.messages
  matching = all_messages.select do |msg|
    recipients = msg["recipients"]
    recipients_array = recipients.is_a?(Array) ? recipients : [recipients]
    recipients_array.any? { |r| r.to_s.include?(recipient) }
  end

  # Filter by subject if provided
  matching = matching.select do |msg|
    msg["subject"].to_s.include?(subject_contains)
  end if subject_contains

  # Get the latest
  latest = matching.max_by { |msg| msg["created_at"] }

  if latest
    {
      found: true,
      message: format_message_detail(latest["id"])
    }
  else
    {
      found: false,
      error: "No matching message found for recipient: #{recipient}"
    }
  end
end

#call_get_message_preview_html(input) ⇒ Object 



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# File 'lib/mail_catcher/integrations/mcp_tools.rb', line 291

def call_get_message_preview_html(input)
  message_id = (input["message_id"] || input[:message_id]).to_i
  mobile = input["mobile"] || input[:mobile] || false

  html_part = Mail.message_part_html(message_id)
  return { error: "No HTML content found in message" } unless html_part

  body = html_part["body"].to_s

  # For mobile, add viewport meta tag if not present
  if mobile && !body.include?("viewport")
    body = "<head><meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\"></head>\n" + body
  end

  # Truncate if very large (limit to ~200KB for performance)
  if body.bytesize > 200_000
    body = body[0, 200_000] + "\n<!-- Truncated for display -->"
  end

  {
    message_id: message_id,
    charset: html_part["charset"] || "utf-8",
    mobile_optimized: mobile,
    size_bytes: body.bytesize,
    html: body
  }
end

#call_get_parsed_auth_info(input) ⇒ Object 



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# File 'lib/mail_catcher/integrations/mcp_tools.rb', line 275

def call_get_parsed_auth_info(input)
  message_id = (input["message_id"] || input[:message_id]).to_i

  return { error: "Message not found" } unless Mail.message(message_id)

  parsed = Mail.parse_message_structured(message_id)
  {
    verification_url: parsed[:verification_url],
    otp_code: parsed[:otp_code],
    reset_token: parsed[:reset_token],
    unsubscribe_link: parsed[:unsubscribe_link],
    links_count: parsed[:all_links]&.count || 0,
    links: parsed[:all_links]&.slice(0, 10) # Return first 10 links
  }
end

#call_search_messages(input) ⇒ Object

Tool implementations



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# File 'lib/mail_catcher/integrations/mcp_tools.rb', line 188

def call_search_messages(input)
  query = input["query"] || input[:query]
  limit = (input["limit"] || input[:limit] || 5).to_i
  has_attachments = input["has_attachments"] || input[:has_attachments]
  from_date = input["from_date"] || input[:from_date]
  to_date = input["to_date"] || input[:to_date]

  results = Mail.search_messages(
    query: query,
    has_attachments: has_attachments,
    from_date: from_date,
    to_date: to_date
  )

  # Limit results
  results = results.slice(0, limit)

  {
    count: results.size,
    messages: results.map { |msg| format_message_summary(msg) }
  }
end

#call_tool(tool_name, input) ⇒ Object

Execute a tool with the given parameters



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# File 'lib/mail_catcher/integrations/mcp_tools.rb', line 159

def call_tool(tool_name, input)
  case tool_name.to_sym
  when :search_messages
    call_search_messages(input)
  when :get_latest_message_for
    call_get_latest_message_for(input)
  when :extract_token_or_link
    call_extract_token_or_link(input)
  when :get_parsed_auth_info
    call_get_parsed_auth_info(input)
  when :get_message_preview_html
    call_get_message_preview_html(input)
  when :delete_message
    call_delete_message(input)
  when :clear_messages
    call_clear_messages(input)
  else
    { error: "Unknown tool: #{tool_name}" }
  end
rescue => e
  {
    error: "Tool execution failed: #{e.message}",
    type: e.class.name,
    backtrace: e.backtrace.first(3)
  }
end

#format_message_detail(message_id) ⇒ Object 



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# File 'lib/mail_catcher/integrations/mcp_tools.rb', line 352

def format_message_detail(message_id)
  msg = Mail.message(message_id)
  return nil unless msg

  {
    id: msg["id"],
    from: msg["sender"],
    to: msg["recipients"],
    subject: msg["subject"],
    size: msg["size"],
    created_at: msg["created_at"],
    has_html: Mail.message_has_html?(message_id),
    has_plain: Mail.message_has_plain?(message_id),
    attachments_count: Mail.message_attachments(message_id)&.count || 0
  }
end

#format_message_summary(message) ⇒ Object

Helper methods



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# File 'lib/mail_catcher/integrations/mcp_tools.rb', line 341

def format_message_summary(message)
  {
    id: message["id"],
    from: message["sender"],
    to: message["recipients"],
    subject: message["subject"],
    size: message["size"],
    created_at: message["created_at"]
  }
end

#tool(name) ⇒ Object

Get tool definition by name



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# File 'lib/mail_catcher/integrations/mcp_tools.rb', line 144

def tool(name)
  TOOLS[name.to_sym]
end

#tool_names ⇒ Object

Get all tool names



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# File 'lib/mail_catcher/integrations/mcp_tools.rb', line 149

def tool_names
  TOOLS.keys.map(&:to_s)
end