Replayable application traces

Use the upstream recorder for model traffic and the Chat capture for application decisions:

import { createRecordingAdapter, createReplayAdapter } from '@agentskit/eval/replay'
import { captureActionPolicyTrace, captureActionTrace, captureTurnTrace, createReplayFixture, createTraceCapture, serializeReplayFixture } from '@agentskit/chat/devtools'

const recording = createRecordingAdapter(adapter)
const capture = createTraceCapture({ redactFields: ['token', 'password', 'authorization'] })

// Wire these into conversation.onTrace and capability-policy onTrace.
const onTurnTrace = (trace) => captureTurnTrace(capture, trace)
const onPolicyTrace = (trace) => captureActionPolicyTrace(capture, trace)
const onActionChange = (confirmation) => captureActionTrace(capture, confirmation)

const route = capture.append({ category: 'route', detail: { routeId: 'support', fromState: 'idle', toState: 'open' } })
capture.append({ category: 'policy', parentId: route.id, detail: { action: 'open-ticket', decision: 'allow' } })

const committedJson = serializeReplayFixture(createReplayFixture(recording.cassette, capture.snapshot()))
const offlineAdapter = createReplayAdapter(recording.cassette)

Store committedJson as a normal JSON fixture. parseReplayFixture validates the application envelope, causal order, and upstream cassette version before replay.

Privacy

Configured redaction matches object field names case-insensitively at every nested depth and replaces values with [REDACTED]. It applies only to application trace details. Upstream cassettes contain adapter requests and streamed chunks, which may include prompts, tool arguments, or model output; sanitize or protect them according to your own retention policy before committing.

Trace schema and limits

Field	Contract
id / parentId	Portable identifiers; a parent must precede its child
sequence	Contiguous, zero-based causal order
at	ISO-8601 timestamp
category	route, agent, repair, fallback, policy, action, or lifecycle
detail	JSON object, maximum 64 KiB UTF-8

A fixture contains at most 10,000 traces and parseReplayFixture refuses JSON larger than 16 MiB before parsing.

Renderer parity

compareRendererOutcomes takes at least two renderer results. Each result identifies semantic outcomes by the composite turnId and kind, so one turn may contain text, component, and action outcomes. The first renderer is the baseline; missing or different outcomes become stable mismatch entries. Object-key order is ignored. Visual layout is intentionally outside this contract.