Add initial claude file

Author: jnunemaker

CLAUDE.md

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+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Development Commands
+
+### Testing
+- `bundle exec rake` - Run all tests (RSpec, Minitest, and Rails tests)
+- `bundle exec rspec` - Run RSpec tests only
+- `bundle exec rake spec:ui` - Run UI-specific specs
+- `bundle exec rake test` - Run Minitest tests only
+- `bundle exec rake test_rails` - Run Rails generator tests
+- `script/test` - Bootstrap and run tests across multiple Rails versions (5.0-8.0)
+
+### Development Setup
+- `script/bootstrap` - Bundle install dependencies and setup binstubs
+- `script/console` - Start interactive console with Flipper loaded (uses Pry)
+- `script/server` - Start local UI server on port 9999 for testing web interface
+
+### Building and Releasing
+- `bundle exec rake build` - Build all gems into pkg/ directory
+- `bundle exec rake release` - Tag version, push to remote, and push gems (requires OTP)
+
+## Architecture Overview
+
+Flipper is a feature flag library for Ruby with a modular adapter-based architecture:
+
+### Core Components
+
+**DSL Layer** (`lib/flipper/dsl.rb`):
+- Main interface for feature flag operations
+- Delegates to Feature instances
+- Handles memoization and instrumentation
+- Thread-safe instance management
+
+**Feature** (`lib/flipper/feature.rb`):
+- Represents individual feature flags
+- Manages enable/disable operations through gates
+- Handles instrumentation events
+- Works with adapters for persistence
+
+**Adapters** (`lib/flipper/adapters/`):
+- Pluggable storage backends (Redis, ActiveRecord, Memory, etc.)
+- Common interface for all storage implementations
+- Support for caching, failover, and synchronization patterns
+
+**Gates** (`lib/flipper/gates/`):
+- Different targeting mechanisms:
+  - Boolean (on/off for everyone)
+  - Actor (specific users/entities)
+  - Group (predefined user groups)
+  - Percentage of Actors (rollout to X% of users)
+  - Percentage of Time (probabilistic enabling)
+  - Expression (complex conditional logic)
+
+### Multi-Gem Structure
+
+The project is structured as multiple gems:
+- `flipper` - Core library
+- `flipper-ui` - Web interface
+- `flipper-api` - REST API
+- `flipper-cloud` - Cloud service integration
+- `flipper-*` - Various adapter gems (redis, active_record, mongo, etc.)
+
+### Key Patterns
+
+**Configuration**: Global configuration through `Flipper.configure` with per-thread instances
+**Instrumentation**: Built-in event system for monitoring and debugging
+**Memoization**: Automatic caching of feature checks within request/thread scope
+**Type Safety**: Strong typing system for actors, percentages, and other values
+
+### Testing
+
+Uses both RSpec (currently preferred for new tests) and Minitest. Shared adapter specs ensure consistency across all storage backends. Extensive testing across multiple Rails versions (5.0-8.0).