diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
new file mode 100644
index 0000000..b9b253c
--- /dev/null
+++ b/.github/copilot-instructions.md
@@ -0,0 +1,91 @@
+# Copilot Instructions for Mixpanel Python SDK
+
+## Project Overview
+This is the official Mixpanel Python library for server-side analytics integration. It provides event tracking, user profile updates, group analytics, and feature flags with both synchronous and asynchronous support.
+
+## Core Architecture
+
+### Main Components
+- **Mixpanel class** (`mixpanel/__init__.py`): Primary entry point supporting both sync/async operations
+- **Consumer pattern**: `Consumer` (immediate) vs `BufferedConsumer` (batched, default 50 messages)
+- **Feature Flags**: Local (client-side evaluation) vs Remote (server-side) providers in `mixpanel/flags/`
+- **Dual sync/async API**: Most flag operations have both variants (e.g., `get_variant`/`aget_variant`)
+
+### Key Design Patterns
+```python
+# Context manager pattern for resource cleanup
+async with Mixpanel(token, local_flags_config=config) as mp:
+    await mp.local_flags.astart_polling_for_definitions()
+
+# Consumer customization for delivery behavior
+mp = Mixpanel(token, consumer=BufferedConsumer())
+
+# Custom serialization via DatetimeSerializer
+mp = Mixpanel(token, serializer=CustomSerializer)
+```
+
+## Development Workflows
+
+### Testing
+- **Run tests**: `pytest` (current Python) or `python -m tox` (all supported versions 3.9-3.13)
+- **Async testing**: Uses `pytest-asyncio` with `asyncio_mode = "auto"` in pyproject.toml
+- **HTTP mocking**: `responses` library for sync code, `respx` for async code
+- **Test structure**: `test_*.py` files in root and package directories
+
+### Building & Publishing
+```bash
+pip install -e .[test,dev]  # Development setup
+python -m build            # Build distributions
+python -m twine upload dist/*  # Publish to PyPI
+```
+
+## Important Conventions
+
+### API Endpoints & Authentication
+- Default endpoint: `api.mixpanel.com` (override via `api_host` parameter)
+- **API secret** (not key) required for `import` and `merge` endpoints
+- Feature flags use `/decide` endpoint; events use `/track`
+
+### Error Handling & Retries
+- All consumers use urllib3.Retry with exponential backoff (default 4 retries)
+- `MixpanelException` for domain-specific errors
+- Feature flag operations degrade gracefully with fallback values
+
+### Version & Dependencies Management
+- Version defined in `mixpanel/__init__.py` as `__version__`
+- Uses Pydantic v2+ for data validation (`mixpanel/flags/types.py`)
+- json-logic library for runtime flag evaluation rules
+
+## Feature Flag Specifics
+
+### Local Flags (Client-side evaluation)
+- Require explicit polling: `start_polling_for_definitions()` or context manager
+- Default 60s polling interval, configurable via `LocalFlagsConfig`
+- Runtime evaluation using json-logic for dynamic targeting
+
+### Remote Flags (Server-side evaluation)
+- Each evaluation makes API call to Mixpanel
+- Better for sensitive targeting logic
+- Configure via `RemoteFlagsConfig`
+
+### Flag Configuration Pattern
+```python
+local_config = mixpanel.LocalFlagsConfig(
+    api_host="api-eu.mixpanel.com",  # EU data residency
+    enable_polling=True,
+    polling_interval_in_seconds=90
+)
+mp = Mixpanel(token, local_flags_config=local_config)
+```
+
+## Testing Patterns
+- Mock HTTP with `responses.activate` decorator for sync tests
+- Use `respx.mock` for async HTTP testing
+- Test consumer behavior via `LogConsumer` pattern (see `test_mixpanel.py`)
+- Always test both sync and async variants of flag operations
+
+## Critical Implementation Notes
+- `alias()` method always uses synchronous Consumer regardless of main consumer type
+- Local flags require explicit startup; use context managers for proper cleanup
+- DateTime serialization handled by `DatetimeSerializer` class
+- All flag providers support custom API endpoints for data residency requirements
\ No newline at end of file
diff --git a/CLAUDE.md b/CLAUDE.md
new file mode 100644
index 0000000..bcf4578
--- /dev/null
+++ b/CLAUDE.md
@@ -0,0 +1,122 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+This is the official Mixpanel Python library for server-side integration. It provides event tracking, user profile updates, group analytics, and feature flags functionality. The library supports both synchronous and asynchronous operations.
+
+## Development Commands
+
+### Environment Setup
+```bash
+# Install development and test dependencies
+pip install -e .[test,dev]
+```
+
+### Testing
+```bash
+# Run all tests across all Python versions (3.9-3.13, PyPy)
+python -m tox
+
+# Run tests for current Python version only
+pytest
+
+# Run with coverage
+python -m coverage run -m pytest
+python -m coverage report -m
+python -m coverage html
+
+# Run specific test file
+pytest test_mixpanel.py
+pytest mixpanel/flags/test_local_feature_flags.py
+```
+
+### Building and Publishing
+```bash
+# Build distribution packages
+python -m build
+
+# Publish to PyPI
+python -m twine upload dist/*
+```
+
+### Documentation
+```bash
+# Build documentation
+python -m sphinx -b html docs docs/_build/html
+
+# Publish docs to GitHub Pages
+python -m ghp_import -n -p docs/_build/html
+```
+
+## Architecture
+
+### Core Components
+
+**Mixpanel Class** (`mixpanel/__init__.py`)
+- Main entry point for all tracking operations
+- Supports context managers (both sync and async)
+- Integrates with Consumer classes for message delivery
+- Optional feature flags providers (local and remote)
+
+**Consumers**
+- `Consumer`: Sends HTTP requests immediately (one per call)
+- `BufferedConsumer`: Batches messages (default max 50) before sending
+- Both support retry logic (default 4 retries with exponential backoff)
+- All consumers support custom API endpoints via `api_host` parameter
+
+**Feature Flags** (`mixpanel/flags/`)
+- `LocalFeatureFlagsProvider`: Client-side evaluation with polling (default 60s interval)
+- `RemoteFeatureFlagsProvider`: Server-side evaluation via API calls
+- Both providers support async operations
+- Types defined in `mixpanel/flags/types.py` using Pydantic models
+
+### Key Design Patterns
+
+1. **Dual Sync/Async Support**: Most feature flag operations have both sync and async variants (e.g., `get_variant` / `aget_variant`)
+
+2. **Consumer Pattern**: Events/updates are sent via consumer objects, allowing customization of delivery behavior without changing tracking code
+
+3. **Context Managers**: The Mixpanel class supports both `with` and `async with` patterns to manage flag provider lifecycle
+
+4. **JSON Serialization**: Custom `DatetimeSerializer` handles datetime objects; extensible via `serializer` parameter
+
+5. **Runtime Rules Engine**: Local flags support runtime evaluation using json-logic library for dynamic targeting
+
+## Testing Patterns
+
+- Tests use `pytest` with `pytest-asyncio` for async support
+- `responses` library mocks HTTP requests for sync code
+- `respx` library mocks HTTP requests for async code
+- Test files follow pattern: `test_*.py` in root or within package directories
+- Pytest config: `asyncio_mode = "auto"` in pyproject.toml
+
+## Dependencies
+
+- `requests>=2.4.2, <3`: HTTP client (sync)
+- `httpx>=0.27.0`: HTTP client (async)
+- `pydantic>=2.0.0`: Data validation and types
+- `asgiref>=3.0.0`: Async utilities
+- `json-logic>=0.7.0a0`: Runtime rules evaluation
+
+## Version Management
+
+Version is defined in `mixpanel/__init__.py` as `__version__` and dynamically loaded by setuptools.
+
+## API Endpoints
+
+Default: `api.mixpanel.com`
+- Events: `/track`
+- People: `/engage`
+- Groups: `/groups`
+- Imports: `/import`
+- Feature Flags: `/decide`
+
+## Important Notes
+
+- API secret (not API key) is required for `import` and `merge` endpoints
+- `alias()` always uses synchronous Consumer regardless of main consumer type
+- Feature flags require opt-in via constructor config parameters
+- Local flags poll for updates; call `start_polling_for_definitions()` or use context manager
+- Retry logic uses urllib3.Retry with exponential backoff