Native library reference. Extended CLI examples use jacs-compat. This source reference can include unreleased changes; see the package guide for installation and MCP profiles for available tools.

Trust Store Operations

The native trust store retains explicitly enrolled public identities for selection by verification and admission workflows. First enrollment requires both the full self-signed agent document and an independently authenticated public key. A fetched Agent Card or its same-origin JWKS does not establish that trust.

Enroll a partner

Obtain partner-agent.json and partner-public.pem through an authenticated channel, then:

from pathlib import Path
from jacs.client import JacsClient

client = JacsClient.quickstart(name="receiver", domain="receiver.example.com")
agent_json = Path("partner-agent.json").read_text()
public_key_pem = Path("partner-public.pem").read_text()
lookup_id = client.trust_agent_with_key(agent_json, public_key_pem)
assert client.is_trusted(lookup_id)

The partner can export these public values with share_agent() and share_public_key(). Enrollment checks the document's self-signature against the supplied key and returns the exact agent_id:version lookup ID. Protect the local trust directory and its writes; native storage uses the OS/XDG JACS data location under trusted_agents, not a universal ~/.jacs/trust_store path.

The Rust equivalent is jacs::trust::trust_agent_with_key(&agent_json, Some(&public_key_pem))?. The older trust_agent(agent_json) refreshes an already enrolled identity; it cannot bootstrap an unknown key.

Use and revoke trust

Check the exact identity/version and verify the signed document before applying application authorization. With local in JACS_KEY_RESOLUTION (the default), the shared native resolver for documents, A2A artifacts and attestations uses this enrollment for v2 signatures by the exact enrolled agent_id:version, and refuses a key that conflicts with it. Other signers and versions need a cached local key or opt-in registry or DNS/HTTPS key discovery. Trust-store membership alone does not validate arbitrary input or approve an action. Retain independently trusted historical keys when old signatures must remain verifiable; UUID versions are identifiers, not ordered ranges.

untrust_agent() records stable-identity distrust and retains historical documents and keys. It does not erase public history. Subsequent trust decisions must honor that marker; re-enrollment is an explicit administrative decision.

DNS TXT records publish a public-key fingerprint, not the key; opt-in discovery fetches the key over HTTPS and checks it against that fingerprint. See DNS trust, verification, and A2A discovery for the separate resolution and admission steps.