diff --git a/DEAR_LLM.md b/DEAR_LLM.md
new file mode 100644
index 0000000..71a4298
--- /dev/null
+++ b/DEAR_LLM.md
@@ -0,0 +1,68 @@
+# DEAR_LLM.md for Sketch Repository
+
+## Repository Architecture
+
+Sketch is an agentic coding tool with a multi-layer architecture:
+
+1. **Outer Sketch**: The CLI command (`sketch`) running on the user's machine
+2. **Inner Sketch**: The binary running inside Docker containers
+3. **Container System**: Docker containers isolate work environments
+
+## Key Components
+
+### Outer Sketch (Host)
+
+- **cmd/sketch/main.go**: Entry point and CLI definitions
+- **dockerimg/**: Container management (building, configuration, orchestration)
+
+### Inner Sketch (Container)
+
+- **loop/agent.go**: Core agent logic and tool implementations
+- **loop/server/**: Server implementation inside containers
+
+### Shared Components
+
+- **webui/**: Web-based user interface components
+- **llm/**: Language model interaction
+
+## Development Workflows
+
+### Development Modes
+
+1. **Container Mode** (Default): `go run ./cmd/sketch -C /path/to/codebase`
+
+   - Creates Docker container for code analysis
+   - Safe and isolated environment
+
+2. **Unsafe Mode**: `go run ./cmd/sketch -unsafe -C /path/to/codebase`
+   - Runs directly on host OS without containerization
+   - Useful for quick testing during development
+
+### Source/Container Relationship
+
+- Target codebase: Copied into container via `COPY . /app`
+- Sketch itself: Binary built specifically for containers (`GOOS=linux`)
+- Container configuration: Generated based on target codebase detection
+
+## Common Gotchas
+
+1. **Container Caching**: Docker image caching may require `-force-rebuild-container` when the target codebase changes
+
+2. **Two Git Contexts**:
+
+   - Sketch's own repository (where outer and inner Sketch code lives)
+   - The target repository being analyzed by Sketch
+   - Keep these separate in your mental model
+
+3. **Inner/Outer Code Changes**:
+   - Changes to inner Sketch (loop/agent.go) are built into the Linux binary for containers
+   - Changes to outer Sketch (dockerimg/) affect how containers are created
+
+## Flags and Settings
+
+- `-unsafe`: Run without containerization
+- `-force-rebuild-container`: Force Docker image rebuilding
+- `-verbose`: Show detailed output and logs
+- `-C /path/to/repo`: Specify target codebase path
+
+See CONTRIBUTING.md for additional development guidance.