GA4GH Agentic Harness Python

An experimental, protocol-neutral async SDK for discovering and invoking GA4GH services through the Agentic Harness Profile. It is local-development software, not a GA4GH-approved standard or certification service.

The package exposes the approved canonical operations through the same Harness class used by the JSON CLI. It has no dependency on MCP; MCP can be implemented as a thin binding over this package later.

Local setup

Python 3.10 or newer and uv are expected.

uv sync --extra dev
uv run pytest
uv run ga4gh-harness ga4gh.harness.describe --pretty

Search the public implementation registry:

uv run ga4gh-harness ga4gh.service.search \
  --input '{"product":"DRS","limit":5}' --pretty

The CLI reads settings prefixed with GA4GH_HARNESS_. For example, use a temporary local ledger without changing the default directory:

GA4GH_HARNESS_LEDGER_PATH=/tmp/ga4gh-runs.db \
  uv run ga4gh-harness ga4gh.harness.describe

See docs/local-development.md for adapters, authentication, testing, and Docker usage.

Python API

from ga4gh_agentic_harness import Harness

async with Harness() as harness:
    result = await harness.service_search(product="Beacon")
    print(result.model_dump(mode="json"))

All public operation results use the common envelope:

• profile_version
• operation
• request_id
• status: success, partial, or failure
• data, errors, and warnings
• trace_id and evidence
• optional page

Security boundary

Inbound Harness authority and outbound service credentials are separate. The SDK never forwards an inbound token. Outbound credentials are opaque runtime objects that are passed only to the safe HTTP client. Tokens, authorization headers, signed URL queries, and DRS access headers are excluded or redacted from envelopes and traces.

The environment bearer provider is for local integration testing. It requires explicit service ID and audience pinning. Production providers should implement broker-backed OAuth, OIDC, token exchange, or GA4GH Passport behavior behind the CredentialProvider protocol.