diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..9c31ec1
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,143 @@
+# Changelog
+
+All notable changes to the Dolibarr MCP Server project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [1.0.0] - 2025-07-10
+
+### Added
+
+#### Core Infrastructure
+- Professional MCP server implementation with comprehensive Dolibarr ERP integration
+- Asynchronous HTTP client with proper session management and error handling
+- Type-safe configuration management with Pydantic validation
+- Comprehensive CLI interface with test and serve commands
+- Professional project structure following Python best practices
+
+#### API Client Features
+- Full async/await architecture for high performance
+- Custom `DolibarrAPIError` exception handling with detailed error information
+- Automatic session management with context manager support
+- Request/response logging for debugging and monitoring
+- Flexible parameter handling for all API endpoints
+
+#### MCP Server Capabilities
+- Complete tool registration following MCP 1.0.0 specification
+- JSON schema validation for all tool inputs and outputs
+- Proper error propagation with meaningful error messages
+- Structured response formatting for LLM consumption
+
+#### Customer/Third Party Management
+- `get_customers` - List customers and suppliers with pagination
+- `get_customer_by_id` - Retrieve specific customer details
+- `create_customer` - Create new customers with full address information
+- `update_customer` - Update existing customer information
+- `delete_customer` - Remove customers from the system
+
+#### Product Management
+- `get_products` - List products with inventory information
+- `get_product_by_id` - Retrieve specific product details
+- `create_product` - Create new products with pricing and stock
+- `update_product` - Update existing product information
+- `delete_product` - Remove products from catalog
+
+#### Invoice Management
+- `get_invoices` - List invoices with status filtering
+- `get_invoice_by_id` - Retrieve specific invoice details
+- `create_invoice` - Create new invoices with line items and calculations
+- `update_invoice` - Update existing invoice information
+- `delete_invoice` - Remove invoices from the system
+
+#### Order Management
+- `get_orders` - List orders with status filtering
+- `get_order_by_id` - Retrieve specific order details
+- `create_order` - Create new orders for customers
+- `update_order` - Update existing order information
+- `delete_order` - Remove orders from the system
+
+#### Contact Management
+- `get_contacts` - List contacts with company associations
+- `get_contact_by_id` - Retrieve specific contact details
+- `create_contact` - Create new contacts with full information
+- `update_contact` - Update existing contact information
+- `delete_contact` - Remove contacts from the system
+
+#### User Management
+- `get_users` - List system users with permissions
+- `get_user_by_id` - Retrieve specific user details
+- `create_user` - Create new system users with roles
+- `update_user` - Update existing user information
+- `delete_user` - Remove users from the system
+
+#### System Tools
+- `test_connection` - Test API connectivity and authentication
+- `get_status` - Retrieve system status and version information
+- `dolibarr_raw_api` - Direct access to any Dolibarr API endpoint
+
+#### Documentation
+- Comprehensive README with installation and usage instructions
+- Professional API documentation based on live testing
+- Environment configuration examples and setup guides
+- Code examples for both MCP and programmatic usage
+
+#### Development Tools
+- Professional `pyproject.toml` with complete metadata
+- Requirements management with pinned versions
+- CLI testing commands for connection verification
+- Type hints throughout the codebase for better IDE support
+
+### Security
+- API key authentication with proper header management
+- Input validation using Pydantic models
+- Safe error handling without credential exposure
+
+### Performance
+- Async/await throughout for non-blocking operations
+- Connection pooling with aiohttp ClientSession
+- Configurable timeouts for API requests
+- Efficient JSON parsing and response handling
+
+### Quality
+- Comprehensive error handling with custom exception types
+- Detailed logging for debugging and monitoring
+- Type safety with full type hints
+- Professional code structure and organization
+
+## [Unreleased]
+
+### Planned for 1.1.0
+- Docker containerization with multi-stage builds
+- Advanced filtering and search capabilities
+- Performance optimization and caching
+- Extended API coverage for additional Dolibarr modules
+
+### Planned for 1.2.0
+- Webhook support for real-time integrations
+- Bulk operations for improved efficiency
+- Enhanced error recovery and retry mechanisms
+- Metrics and monitoring capabilities
+
+### Planned for 2.0.0
+- Web UI for server management
+- Multi-instance support
+- Plugin system for extensibility
+- Advanced business intelligence features
+
+---
+
+## Guidelines
+
+### Types of Changes
+- **Added** for new features
+- **Changed** for changes in existing functionality
+- **Deprecated** for soon-to-be removed features
+- **Removed** for now removed features
+- **Fixed** for any bug fixes
+- **Security** for vulnerability fixes
+
+### Version Numbers
+- **Major** version when making incompatible API changes
+- **Minor** version when adding functionality in a backwards compatible manner
+- **Patch** version when making backwards compatible bug fixes