mcp_bundle 0.2.1

Bundle schema, loader, validator, expression language, and port contracts providing the foundation for the MCP ecosystem.

MCP Bundle

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MCP Knowledge Package Family

• mcp_bundle: Bundle schema, loader, validator, expression language, and port contracts for MCP ecosystem.
• mcp_fact_graph: Temporal knowledge graph with evidence-based fact management and summarization.
• mcp_skill: Skill definitions and runtime execution for AI capabilities.
• mcp_profile: Profile definitions for AI personas with template rendering and appraisal.
• mcp_knowledge_ops: Knowledge operations including pipelines, workflows, and scheduling.
• mcp_knowledge: Unified integration package for the complete knowledge system.

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A foundational Dart package providing bundle schema definitions, loading, validation, expression language, and port contracts for the MCP ecosystem. This is the core package that other MCP packages depend on.

Features

Core Features

• Bundle Schema: Define and structure MCP bundles with skills, profiles, and knowledge
• Bundle Loader: Load bundles from files, URLs, or raw data
• Bundle Validator: Validate bundle structure and content
• Expression Language: Powerful expression evaluation for dynamic content
• Port Contracts: Universal interfaces for LLM, Storage, Metrics, Events, and Channels

Port Contracts (package:mcp_bundle/ports.dart)

• LlmPort: LLM completion interface
• StoragePort: Key-value and document storage
• MetricPort: Metrics and telemetry
• EventPort: Event publishing and subscription
• ChannelPort: Bidirectional channel communication (Slack, Telegram, Discord, HTTP, WebSocket)

Bundle Model

• Skills: Skill definitions within bundles
• Profiles: Profile definitions within bundles
• Knowledge: Knowledge items within bundles
• Metadata: Bundle versioning and metadata

Expression Language

• Variable Access: {{variable}} syntax
• Conditionals: {{#condition}}...{{/condition}}
• Loops: {{#array}}...{{/array}}
• Functions: Built-in functions for data manipulation

Quick Start

Installation

Add to your pubspec.yaml:

dependencies:
  mcp_bundle: ^0.2.0

Basic Usage

import 'package:mcp_bundle/mcp_bundle.dart';

void main() async {
  // Create a bundle
  final bundle = McpBundle(
    id: 'my_bundle',
    name: 'My AI Bundle',
    version: '1.0.0',
    skills: [
      BundleSkill(
        id: 'summarizer',
        name: 'Text Summarizer',
        description: 'Summarizes text content',
        executor: 'llm',
        prompt: 'Summarize: {{input.text}}',
      ),
    ],
    profiles: [
      BundleProfile(
        id: 'assistant',
        name: 'Helpful Assistant',
        systemPrompt: 'You are a helpful assistant for {{user.name}}.',
      ),
    ],
  );

  // Validate bundle
  final validator = BundleValidator();
  final validation = await validator.validate(bundle);

  if (validation.isValid) {
    print('Bundle is valid!');
  } else {
    print('Errors: ${validation.errors}');
  }

  // Save bundle
  final loader = BundleLoader();
  await loader.save(bundle, 'my_bundle.mcpb');
}

Channel Port

The Channel Port provides a universal bidirectional communication interface for messaging platforms.

Channel Port Types

import 'package:mcp_bundle/ports.dart';

// Channel Identity - identifies a platform
final identity = ChannelIdentity(
  platform: 'slack',      // slack, telegram, discord, http, websocket
  channelId: 'T123456',   // workspace ID, server ID, etc.
  displayName: 'My Workspace',
);

// Conversation Key - unique conversation identifier
final conversation = ConversationKey(
  channel: identity,
  conversationId: 'C789',  // channel, thread, or DM ID
  userId: 'U123',          // optional user context
);

// Channel Event - incoming event
final event = ChannelEvent.message(
  id: 'evt_123',
  conversation: conversation,
  text: 'Hello, bot!',
  userId: 'U123',
  userName: 'John Doe',
);

// Channel Response - outgoing message
final response = ChannelResponse.text(
  conversation: conversation,
  text: 'Hi there! How can I help?',
  replyTo: event.id,
);

// Rich response with blocks (Slack, Discord)
final richResponse = ChannelResponse.rich(
  conversation: conversation,
  blocks: [
    {'type': 'section', 'text': {'type': 'mrkdwn', 'text': '*Hello!*'}},
  ],
  text: 'Hello!',  // fallback text
);

Channel Capabilities

// Check what features a channel supports
final capabilities = ChannelCapabilities(
  text: true,
  richMessages: true,
  attachments: true,
  reactions: true,
  threads: true,
  editing: true,
  deleting: true,
  typingIndicator: true,
  maxMessageLength: 4000,
);

// Presets
final fullCapabilities = ChannelCapabilities.full();
final textOnly = ChannelCapabilities.textOnly();

Implementing ChannelPort

import 'package:mcp_bundle/ports.dart';

class MyChannelPort implements ChannelPort {
  final _eventController = StreamController<ChannelEvent>.broadcast();

  @override
  ChannelIdentity get identity => ChannelIdentity(
    platform: 'my-platform',
    channelId: 'channel-1',
  );

  @override
  ChannelCapabilities get capabilities => ChannelCapabilities.textOnly();

  @override
  Stream<ChannelEvent> get events => _eventController.stream;

  @override
  Future<void> start() async {
    // Start receiving events
  }

  @override
  Future<void> stop() async {
    await _eventController.close();
  }

  @override
  Future<void> send(ChannelResponse response) async {
    // Send message to platform
  }

  @override
  Future<void> sendTyping(ConversationKey conversation) async {
    // Show typing indicator
  }

  @override
  Future<void> edit(String messageId, ChannelResponse response) async {
    // Edit existing message
  }

  @override
  Future<void> delete(String messageId) async {
    // Delete message
  }

  @override
  Future<void> react(String messageId, String reaction) async {
    // Add reaction to message
  }
}

Testing with Stub Ports

// StubChannelPort for unit testing
final stub = StubChannelPort();
await stub.start();

// Simulate incoming event
stub.simulateEvent(ChannelEvent.message(
  id: 'test-1',
  conversation: testConversation,
  text: 'Test message',
));

// Check sent responses
expect(stub.sentResponses, hasLength(1));

// EchoChannelPort echoes messages back
final echo = EchoChannelPort();
await echo.start();
echo.events.listen((event) {
  print('Received: ${event.text}');  // "Echo: Hello"
});
await echo.send(ChannelResponse.text(
  conversation: testConversation,
  text: 'Hello',
));

Core Concepts

McpBundle

The main bundle container:

final bundle = McpBundle(
  id: 'customer_service',
  name: 'Customer Service AI',
  version: '2.0.0',
  description: 'AI capabilities for customer service',
  skills: [...],
  profiles: [...],
  knowledge: [...],
  metadata: {
    'author': 'MakeMind',
    'category': 'customer-service',
  },
);

Bundle Loader

Load and save bundles:

final loader = BundleLoader();

// Load from file
final bundle = await loader.load('path/to/bundle.mcpb');

// Load from URL
final remoteBundle = await loader.loadFromUrl('https://example.com/bundle.mcpb');

// Load from raw data
final dataBundle = await loader.loadFromJson(jsonData);

// Save bundle
await loader.save(bundle, 'output.mcpb');

Bundle Validator

Validate bundle structure and content:

final validator = BundleValidator();

final validation = await validator.validate(bundle);

print('Valid: ${validation.isValid}');
print('Errors: ${validation.errors}');
print('Warnings: ${validation.warnings}');

// Validate specific parts
final skillValidation = await validator.validateSkills(bundle.skills);
final profileValidation = await validator.validateProfiles(bundle.profiles);

Expression Language

Evaluate expressions with context:

final expression = ExpressionEvaluator();

// Simple variable access
final result = expression.evaluate(
  '{{user.name}}',
  {'user': {'name': 'John'}},
);
// Result: 'John'

// Conditional sections
final conditional = expression.evaluate(
  '{{#isPremium}}Premium features enabled{{/isPremium}}',
  {'isPremium': true},
);
// Result: 'Premium features enabled'

// Array iteration
final loop = expression.evaluate(
  '{{#items}}Item: {{name}}\n{{/items}}',
  {'items': [{'name': 'A'}, {'name': 'B'}]},
);
// Result: 'Item: A\nItem: B\n'

Bundle Schema

Skills in Bundle

BundleSkill(
  id: 'analyzer',
  name: 'Text Analyzer',
  description: 'Analyzes text content',
  inputSchema: {
    'type': 'object',
    'properties': {
      'text': {'type': 'string'},
    },
  },
  outputSchema: {
    'type': 'object',
    'properties': {
      'sentiment': {'type': 'string'},
      'topics': {'type': 'array'},
    },
  },
  executor: 'llm',
  prompt: 'Analyze: {{input.text}}',
  tags: ['nlp', 'analysis'],
)

Profiles in Bundle

BundleProfile(
  id: 'expert',
  name: 'Domain Expert',
  description: 'Expert in specific domain',
  systemPrompt: '''
You are an expert in {{domain}}.
Help the user with {{task}}.
''',
  variables: ['domain', 'task'],
  tags: ['expert'],
)

Knowledge in Bundle

BundleKnowledge(
  id: 'faq',
  name: 'FAQ Knowledge',
  type: 'document',
  content: 'Frequently asked questions...',
  metadata: {
    'source': 'internal',
    'lastUpdated': '2025-01-01',
  },
)

API Reference

BundleLoader

Method	Description
load(path)	Load bundle from file
loadFromUrl(url)	Load bundle from URL
loadFromJson(json)	Load from JSON data
save(bundle, path)	Save bundle to file

BundleValidator

Method	Description
validate(bundle)	Validate entire bundle
validateSkills(skills)	Validate skills
validateProfiles(profiles)	Validate profiles
validateKnowledge(knowledge)	Validate knowledge

ExpressionEvaluator

Method	Description
evaluate(template, context)	Evaluate expression
validate(template)	Validate expression syntax
extractVariables(template)	Extract variable names

ChannelPort

Property/Method	Description
identity	Channel identity
capabilities	Channel capabilities
events	Stream of incoming events
start()	Start receiving events
stop()	Stop receiving events
send(response)	Send response to channel
sendTyping(conversation)	Send typing indicator
edit(messageId, response)	Edit sent message
delete(messageId)	Delete sent message
react(messageId, reaction)	Add reaction

Examples

Complete Examples Available

• example/basic_bundle.dart - Basic bundle creation
• example/bundle_loading.dart - Loading and saving bundles
• example/expression_language.dart - Expression evaluation
• example/validation.dart - Bundle validation
• example/channel_port.dart - Channel port usage

Contributing

We welcome contributions! Please see our Contributing Guide for details.

Support

• Documentation
• Issue Tracker
• Discussions
• Support on Patreon

License

This project is licensed under the MIT License - see the LICENSE file for details.