qerexa (Python, preview)

Python clients for Qerexa:

• QerexaGateMiddleware — decorator that runs a function only after a direct, unexpired Qerexa allowed decision. Works for AutoGen functions and any plain Python function, including CrewAI or LangChain tool functions.
• QerexaVCClient — issue and verify verifiable credentials, federation tokens, and trust relationships.

Install

pip install qerexa

Gate a function

import os
from qerexa import (
    ExecutionAuthorizationRequiredError,
    GateBlockedError,
    QerexaGateMiddleware,
)

gate = QerexaGateMiddleware(api_key=os.environ["QEREXA_API_KEY"])

@gate.gate_check(action="report.export", reasoning="Monthly compliance export")
def export_report(report_id: str) -> str:
    ...

try:
    export_report("rpt_123")
except ExecutionAuthorizationRequiredError as e:
    # Human review was requested (flow e.flow_id). Approval of that review does
    # not authorize this call; stop here or use an action-bound execution flow.
    ...
except GateBlockedError as e:
    ...

The wrapped function runs only for HTTP 200 with decision: "allowed", allowed: true, a decision_id, and a future, timezone-aware expires_at. Everything else raises and the function does not run: blocked, approval_required, expired or malformed allows, non-JSON responses, and network errors (QerexaError, the base of both errors above).

Function arguments are never sent. Qerexa receives the action, the actor, the reasoning you pass (default: the function name), and metadata. Do not put credentials or customer data in either.

For CrewAI, decorate the function that implements the tool before handing it to CrewAI; the gate then runs on every call regardless of CrewAI callbacks.

Verifiable credentials

from qerexa import VCClientConfig, create_vc_client

vc = create_vc_client(VCClientConfig(org_id="org_123", api_key=os.environ["QEREXA_API_KEY"]))
relationships = vc.list_trust_relationships(limit=10)

Requests time out after 10 seconds by default (VCClientConfig(timeout=...)).

Preview limits

This package is not a regulated execution adapter. It does not verify receipts, poll or resume review flows, or bind an approval to a specific execution. Use the documented API proof flow and an independently reviewed execution contract for high-impact actions.

Development

python -m pip install -e "./packages/sdk-python[dev]"
ruff check packages/sdk-python
pytest packages/sdk-python

Releases follow the SDK release runbook.