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+# Agent Instructions: PhotoTools3
+
+## Environment Setup
+Requires a `.env` file with the following variables:
+- `llm_api_key`: API key for the LLM provider.
+- `llm_api_base_url`: Base URL for the LLM API.
+- `llm_default_temperature`: Float value for temperature.
+
+## Development Toolchain
+- **Dependency Management**: Use `uv`.
+- **Python Version**: Requires Python `>=3.14`.
+- **Testing**: Run `pytest` to execute the test suite in `test/`.
+- **Linting & Formatting**: Use `ruff` and `black`.
+
+## CLI Usage
+The primary entry point is the `photools3` command:
+- `photools3 keywords <image_path>`: Extracts keywords and captions from a single image.
+
+## Architecture & Logic
+- **`src/photools3/photo.py`**: Core image processing logic, including resizing, RGB conversion, and generating base64 JPEG encodings specifically for LLM vision compatibility.
+- **`src/photools3/llm_session.py`**: Manages the workflow of sending processed images to the LLM and parsing results.
+- **Configuration**: The list of keywords to extract is maintained in `config/keywords.txt`.