@geometra/evidence

Portable evidence packets for Geometra agent-native UI replay.

@geometra/evidence turns AgentGatewayReplay records from @geometra/core into verifiable packets that answer what an agent saw, which semantic actions were available, what policy/approval path ran, and what changed afterward.

import { createEvidencePacket, signEvidencePacket, verifyEvidencePacket } from '@geometra/evidence'

const replay = gateway.getReplay()
const packet = await createEvidencePacket(replay, {
  packetId: 'claims-run-1',
  redact: { keys: ['token', 'authorization'] },
})

const signed = await signEvidencePacket(packet, signer)
const verified = await verifyEvidencePacket(signed, { verifier })

What A Packet Contains

• Semantic geometry frames from the same tree rendered to humans.
• Stable action ids, risk, titles, bounds, and action contracts.
• Requested, approved, denied, completed, and failed trace events.
• Before/after frame snapshots for replayable review.
• Integrity hashes over replay, trace, frames, and actions.
• Optional detached signature metadata using a pluggable signer.

Exports

• exportEvidenceToOtelSpans(packet) creates lightweight OpenTelemetry-style spans for observability backends.
• exportEvidenceToIsoReceipt(packet) creates a receipt-input object compatible with Agent Pattern Labs ISO receipt conventions.

Signing

The core signing API is deliberately pluggable:

const signed = await signEvidencePacket(packet, {
  alg: 'Ed25519',
  kid: 'key-1',
  sign: payload => mySigner(payload),
})

For environments with Web Crypto Ed25519 support, the package also exports createSubtleEd25519Signer, createSubtleEd25519Verifier, and generateSubtleEd25519KeyPair.