Sign and Verify

from jacs.client import JacsClient

client = JacsClient.quickstart(name="my-agent", domain="my-agent.example.com")

# Sign an artifact
signed = client.sign_artifact({"action": "classify", "input": "data"}, "artifact")

# Verify it (with trust assessment)
a2a = client.get_a2a()
result = a2a.verify_wrapped_artifact(signed, assess_trust=True)
print(f"Valid: {result['valid']}, Allowed: {result['trust']['allowed']}")

Chain of Custody

When multiple agents process data in sequence, link artifacts into a verifiable chain:

# Agent A signs step 1
step1 = client_a.sign_artifact({"step": 1, "data": "raw"}, "artifact")

# Agent B signs step 2, referencing step 1 as parent
step2 = client_b.sign_artifact(
    {"step": 2, "data": "processed"},
    "artifact",
    parent_signatures=[step1],
)

# Verify the full chain
result = a2a.verify_wrapped_artifact(step2)
assert result["valid"]
assert result["parent_signatures_valid"]

Build an Audit Trail

chain = a2a.create_chain_of_custody([step1, step2])
# Metadata only: chainOfCustody, created, totalArtifacts.
# This helper does not verify signatures, ordering or validity.

Sign and Verify

const { JacsClient } = require('@hai.ai/jacs/client');

const client = await JacsClient.quickstart({
  name: 'my-agent',
  domain: 'my-agent.example.com',
});

// Sign an artifact
const signed = await client.signArtifact({ action: 'classify', input: 'data' }, 'task');

// Verify it
const a2a = client.getA2A();
const result = a2a.verifyWrappedArtifact(signed);
console.log(`Valid: ${result.valid}`);

Chain of Custody

// Agent A signs step 1
const step1 = await clientA.signArtifact({ step: 1, data: 'raw' }, 'message');

// Agent B signs step 2, referencing step 1
const step2 = await clientB.signArtifact(
  { step: 2, data: 'processed' }, 'message', [step1],
);

// Verify the full chain
const result = a2a.verifyWrappedArtifact(step2);
console.log(`Chain valid: ${result.valid}`);
console.log(`Parents valid: ${result.parentSignaturesValid}`);