Context Mapper

npm version License: MIT

An MCP (Model Context Protocol) server that enables AI assistants to work with Domain-Driven Design models using Context Mapper's CML (Context Mapping Language).

Features

• Parse and serialize CML files - Full support for Context Mapper's CML syntax
• Manage bounded contexts - Create, update, delete bounded contexts
• Work with aggregates - Define entities, value objects, domain events, commands, and services
• Context map relationships - Define and manage relationships between bounded contexts (Partnership, SharedKernel, Upstream-Downstream with patterns like OHS, PL, ACL, CF)
• Generate PlantUML diagrams - Visualize context maps and aggregate structures
• Real-time validation - Catch errors at creation time, not at save time
• ID Value Objects - Dedicated tool for creating DDD-compliant identifier types

Validation Features

The server validates models in real-time to prevent common CML errors:

Validation	When	Example Error
Duplicate names	On create	'AgentId' already exists in ContextA...
Invalid types	On create	Map<K,V> is not supported in CML...
Reserved names	On create	'Resource' is a reserved keyword...
Reserved attributes	On save	Auto-escaped with ^ prefix

Valid Attribute Types

• Primitives: String, int, long, boolean, DateTime, BigDecimal, UUID
• Collections: List<Type>, Set<Type>
• References: - TypeName (reference to domain objects)

Invalid Types (Rejected)

• Map<K,V>, Any, Tuple, Runnable, Callbacks, nested generics

Installation

Claude Code

claude mcp add context-mapper -- npx -y context-mapper-mcp@latest

Claude Desktop

Add to your Claude Desktop configuration (claude_desktop_config.json):

{
  "mcpServers": {
    "context-mapper": {
      "command": "npx",
      "args": ["-y", "context-mapper-mcp@latest"]
    }
  }
}

Available Tools

Model Management

Tool	Description
cml_create_model	Create a new empty CML model
cml_load_model	Load a CML file
cml_save_model	Save model to disk
cml_validate_model	Validate CML syntax and semantics
cml_get_model_info	Get model statistics

Query Tools

Tool	Description
cml_list_bounded_contexts	List all bounded contexts
cml_get_bounded_context	Get context details
cml_list_aggregates	List aggregates (optionally filtered by context)
cml_get_aggregate	Get aggregate with all its elements
cml_find_elements	Search by name pattern (regex)
cml_list_relationships	List context map relationships

Context Tools

Tool	Description
cml_create_context_map	Create a context map
cml_create_bounded_context	Create a bounded context
cml_update_bounded_context	Update a bounded context
cml_delete_bounded_context	Delete a bounded context

Aggregate Tools

Tool	Description
cml_create_aggregate	Create an aggregate
cml_update_aggregate	Update an aggregate
cml_delete_aggregate	Delete an aggregate
cml_add_entity	Add entity to aggregate
cml_add_value_object	Add value object
cml_add_identifier	Add ID value object (DDD best practice)
cml_add_domain_event	Add domain event
cml_add_command	Add command
cml_add_service	Add domain service
cml_batch_add_elements	Batch create multiple domain objects in one call
cml_delete_entity	Delete entity
cml_delete_value_object	Delete value object
cml_delete_domain_event	Delete domain event
cml_delete_command	Delete command
cml_delete_service	Delete service

Batch Creation (cml_batch_add_elements)

Create multiple domain objects in a single call for improved efficiency:

{
  "contextName": "CustomerManagement",
  "aggregateName": "Customer",
  "identifiers": [
    { "name": "CustomerId" }
  ],
  "entities": [
    {
      "name": "Customer",
      "aggregateRoot": true,
      "attributes": [
        { "name": "id", "type": "- CustomerId", "key": true },
        { "name": "email", "type": "String" }
      ]
    }
  ],
  "valueObjects": [
    {
      "name": "Address",
      "attributes": [
        { "name": "street", "type": "String" },
        { "name": "city", "type": "String" }
      ]
    }
  ],
  "domainEvents": [
    { "name": "CustomerRegistered", "attributes": [{ "name": "customerId", "type": "- CustomerId" }] }
  ],
  "commands": [
    { "name": "RegisterCustomer", "attributes": [{ "name": "email", "type": "String" }] }
  ]
}

Benefits:

• Faster: Single round-trip instead of 8+ individual calls
• Atomic validation: All elements validated before any are created
• Error handling: Use failFast: false to collect all errors at once

Relationship Tools

Tool	Description
cml_create_relationship	Create context map relationship
cml_update_relationship	Update relationship
cml_delete_relationship	Delete relationship
cml_get_relationship	Get relationship details

Supported relationship types:

• Partnership - Symmetric, both contexts cooperate
• SharedKernel - Symmetric, shared code/models
• UpstreamDownstream - Asymmetric with patterns:
  • Upstream: OHS (Open Host Service), PL (Published Language)
  • Downstream: ACL (Anticorruption Layer), CF (Conformist)

Generation Tools

Tool	Description
cml_generate_context_map_diagram	Generate PlantUML context map
cml_generate_aggregate_diagram	Generate aggregate class diagram
cml_generate_full_diagram	Generate full model diagram

Example CML File

ContextMap ECommerceContextMap {
    type = AS_IS
    contains CustomerManagement, OrderManagement, Inventory

    CustomerManagement [U,OHS,PL] -> [D,ACL] OrderManagement
    OrderManagement [U] -> [D,CF] Inventory
}

BoundedContext CustomerManagement {
    domainVisionStatement = "Manages customer data"
    implementationTechnology = "TypeScript"

    Aggregate Customer {
        Entity Customer {
            aggregateRoot
            key String customerId
            String email
            String firstName
        }

        ValueObject Address {
            String street
            String city
        }

        DomainEvent CustomerRegistered {
            String customerId
            Date registeredAt
        }

        Command RegisterCustomer {
            String email
            String firstName
        }
    }
}

Development

git clone https://github.com/thijs-hakkenberg/contextmapper_mcp.git
cd contextmapper_mcp
npm install
npm run build
npm test

Architecture

• Parser: Chevrotain-based lexer and parser for CML syntax
• Writer: Serializes model back to CML format
• Validation: Checks model consistency and semantic rules
• Tools: MCP tool implementations for all operations
• Generators: PlantUML diagram generators

License

MIT