Arbiter Python SDK

Official Python client for the Arbiter Control Plane. Same governance semantics as @arbiterhq/sdk (Node): evaluate → allow | hold | deny.

Package: arbiter-sdk==0.1.1
Import: from arbiter import ArbiterRuntime

Install

pip install arbiter-sdk==0.1.1

Authority Connect (arbiter connect --apply) installs the public pin configured in the CLI (currently arbiter-sdk==0.1.0 or newer compatible pins) into Python projects after confirmation. When you are developing inside the Arbiter monorepo, Connect may use an on-disk editable path instead.

Development / contributor only

pip install -e packages/python
# or:
export ARBITER_PYTHON_SDK_PIP_SPEC=/path/to/arbiter_sdk-0.1.1-py3-none-any.whl

Do not use the editable monorepo path as the customer install instruction.

Environment variables

You can also pass api_key/credential, base_url, and agent to ArbiterRuntime(...).

Quick start

from arbiter import ArbiterRuntime

runtime = ArbiterRuntime()  # reads ARBITER_API_KEY / ARBITER_BASE_URL / ARBITER_AGENT
runtime.connect(framework="custom", runtimeType="python")

result = runtime.evaluate("send_payment", amount=100)

if result.decision == "allow":
    ...
elif result.decision == "deny":
    ...
elif result.decision == "hold":
    # Approval HOLD includes approval_request_id for Dashboard / Authorizations Approve.
    # API keys cannot approve. This package does not expose completeHeldEvaluation;
    # Node SDK and Authority Gate can complete held evaluations in-process.
    # Discovery HOLD requires a human to Adopt the agent, then retry evaluate.
    ...

Governance boundaries

Arbiter governs agents. It does not replace human security decisions:

• Discovery observes runtimes. Humans Adopt agents before enforcement begins.
• Approval HOLD pauses side effects. Humans Approve (or deny) in the Dashboard.
• Connect and this SDK never auto-Adopt Discovery resources.
• Connect and this SDK never auto-Approve HOLD decisions.
• API keys cannot approve; approval requires a human session.

Normal lifecycle:

connect / observe → Adopt (human) → evaluate → allow | hold | deny
                              hold (approval) → Approve (human) → continue

API surface

Companion packages