UN-3232 [FEAT] Implement back-off retry mechanism with deadline-aware timeout budgeting

CONTRIBUTING.md

@@ -0,0 +1,113 @@
+# Contributing
+
+Guide for setting up a local development environment and running tests.
+
+## Prerequisites
+
+- Python 3.12+
+- [uv](https://docs.astral.sh/uv/) (recommended) or `pip`
+
+## Setup
+
+```bash
+git clone https://github.com/Zipstack/llm-whisperer-python-client.git
+cd llm-whisperer-python-client
+
+# Create a virtual environment and install all dependencies
+uv sync --group dev --group test
+
+# Either prefix commands with `uv run` (used throughout this guide),
+# or activate the venv manually:
+#   source .venv/bin/activate        # Linux / macOS
+#   .venv\Scripts\activate           # Windows
+```
+
+If you prefer pip:
+
+```bash
+python -m venv .venv
+source .venv/bin/activate  # On Windows: .venv\Scripts\activate
+pip install -e ".[dev,test]"
+```
+
+## Environment variables
+
+The project uses [`pytest-dotenv`](https://pypi.org/project/pytest-dotenv/) to auto-load environment variables from a `.env` file in the project root.
+
+```bash
+cp sample.env .env
+```
+
+Edit `.env` and fill in your API key:
+
+| Variable | Description | Required for |
+|---|---|---|
+| `LLMWHISPERER_BASE_URL_V2` | API base URL (v2) | Integration tests |
+| `LLMWHISPERER_API_KEY` | Your LLMWhisperer API key | Integration tests |
+| `LLMWHISPERER_LOG_LEVEL` | Log level (`DEBUG`, `INFO`, etc.) | Optional |
+
+Unit tests are fully mocked and do **not** require a `.env` file or API key.
+
+## Running tests
+
+### Unit tests (no API key needed)
+
+```bash
+uv run pytest tests/unit/ -v
+```
+
+### Integration tests (requires valid `.env`)
+
+```bash
+uv run pytest tests/integration/ -v
+```
+
+### All tests
+
+```bash
+uv run pytest -v
+```
+
+### Via tox
+
+```bash
+uv run tox
+```
+
+This runs tests under Python 3.12 using `uv sync --group test` to install dependencies.
+
+### Via poe
+
+```bash
+uv run poe test
+```
+
+## Linting and formatting
+
+The project uses [ruff](https://docs.astral.sh/ruff/) for linting and formatting (configured in `pyproject.toml`).
+
+```bash
+# Lint
+uv run ruff check src/ tests/
+
+# Auto-fix lint issues
+uv run ruff check --fix src/ tests/
+
+# Format
+uv run ruff format src/ tests/
+```
+
+## Project structure
+
+```
+src/unstract/llmwhisperer/
+    __init__.py          # Package version
+    client_v2.py         # Main client (LLMWhispererClientV2)
+    utils.py             # Utility helpers
+
+tests/
+    conftest.py          # Shared fixtures
+    unit/                # Mocked tests (no network calls)
+    integration/         # Tests against the live API
+    test_data/           # Sample files used by tests
+```

pyproject.toml

@@ -18,7 +18,7 @@ classifiers = [
     "Topic :: Software Development :: Libraries :: Python Modules",
 ]
 requires-python = ">=3.12"
-dependencies = ["requests>=2"]
+dependencies = ["requests>=2", "tenacity>=8.0"]
 
 [dependency-groups]
 test = [