powered by DataGOLThe package on PyPI is harnessx and the import namespace is harnessx. Python 3.11 or newer is required.
Install the SDK
Add it to a uv project:
uv add harnessx
Any other installer works the same way; the package has no build step:
pip install harnessx
Optional dependencies
Install only the integrations your application uses, as extras:
uv add "harnessx[openai]"
uv add "harnessx[mcp,postgres]"
uv add "harnessx[all]"
| Extra | Adds |
|---|---|
| openai | OpenAI provider dependencies |
| azure | Azure OpenAI provider (same dependencies as openai) |
| openrouter | OpenRouter provider dependencies |
| gemini | Google GenAI provider |
| jev | TypeSafe SDK for Choice, Score, and Noul decisions |
| mcp | MCP clients and CLI |
| postgres | Psycopg SQL backend dependencies |
| temporal | Temporal, Redis, and S3 client dependencies |
| docker | Docker SDK; a running daemon is also required |
| langsmith | Tracing and evaluations |
| server | FastAPI and Uvicorn for the web examples |
| all | Every integration extra above |
Installing an extra does not provision an external service or validate credentials. Importing decision types and running the offline Jev examples do not require the jev extra; live decisions do. See Decisions with Jev.
Configure credentials
The default provider reads ANTHROPIC_API_KEY from the process environment. Configure other providers as described in Model providers.
export ANTHROPIC_API_KEY="your-api-key"
For live Jev decisions, configure a separate TypeSafe key:
export TYPESAFE_API_KEY="your-typesafe-key"
Live routing also requires the selected generative provider's key and model. Classification and review can call Jev independently. See Decisions with Jev.
A standalone Agent application does not load a .env file for you; call load_dotenv yourself or export the variables before launching Python. The repository examples and harness-web load the repository's .env.
Work from the repository
The examples and harness-web live in the repository, not in the package. Clone it and let uv build the environment from the committed lockfile:
git clone https://github.com/datagol/agent-harness-x.git
cd agent-harness-x
uv sync --all-extras
uv run python -m examples.simple_chat
uv sync --all-extras installs the SDK in editable mode with every integration and the development tools, so uv run pytest -q runs the suite offline. Do not append .py to a module command. See Examples for what each entry point needs.
Check the installed version
uv pip show harnessx
This documentation describes harnessx 0.4; if you are upgrading from 0.3, read Migrating to 0.4 for every renamed and removed name. See Implementation status for backend qualification limits.