No implementation currently clears the Snapshot + Claim threshold; this is not a claim that the product lacks the capability.
Inspect coverage boundary →MECHANISM · OBSERVABILITY · CORE
Event Stream
Translate provider deltas and harness transitions into ordered, replayable events.
3 lessons5 agent snapshots1 experiments
observabilityevent-streamproblem → policy → evidence
L0Intuitionpartial
L1Buildcomplete
L2Engineeringpartial
L3Architecturemissing
L4Researchmissing
DEPENDENCY GRAPH · READER PATH
What feeds it, and what does it unlock?
Arrows show learning and design dependencies, not runtime data flow. Follow any node to continue through the Atlas.
Prerequisites
event-streamEvent StreamCurrent research boundary
Translate provider deltas and harness transitions into ordered, replayable events.
The structured record is in the Atlas, but the L0–L4 article has not passed content review.
AGENT MAPPING · EVIDENCE ONLY
Snapshot implementations
An implementation enters the map only when both a snapshot and claims exist; unknowns remain visible.
1 evidence-backed claim.
codex-2026-08-10-source →1 evidence-backed claim.
grok-build-2026-08-10-source →1 evidence-backed claim.
opencode-2026-08-10-source →1 evidence-backed claim.
pi-2026-08-10-source →1 evidence-backed claim.
reasonix-2026-08-10-source →No implementation currently clears the Snapshot + Claim threshold; this is not a claim that the product lacks the capability.
Inspect coverage boundary →CLAIMS · EVIDENCE LEDGER5 RECORDS
source + sourcereviewed
codex-source-event-stream
The pinned Codex protocol defines typed events for turn lifecycle, streamed content, tools, approvals, compaction, hooks, and collaborative-agent activity, and the turn implementation emits those events through the session boundary.
- Agent
- Codex
- Snapshot
- codex-2026-08-10-source
- Reviewed
- 2026-08-10
source + sourcereviewed
grok-build-source-event-log
Grok Build's pinned file-event utilities write versioned session events as append-oriented JSONL, and the tracker emits typed turn, tool, permission, and terminal lifecycle records.
- Agent
- Grok Build
- Snapshot
- grok-build-2026-08-10-source
- Reviewed
- 2026-08-10
sourcereviewed
opencode-source-event-bridge
OpenCode's pinned event bridge enriches events with location and aggregate identity, assigns version and sequence metadata for durable records, and forwards public events through the global bus.
- Agent
- OpenCode
- Snapshot
- opencode-2026-08-10-source
- Reviewed
- 2026-08-10
source + sourcereviewed
pi-source-session-events
Pi combines a live typed AgentEvent stream with an append-only JSONL session tree whose entries carry id and parentId, allowing the active context to move between branches without deleting prior history.
- Agent
- Pi
- Snapshot
- pi-2026-08-10-source
- Reviewed
- 2026-08-10
source + sourcereviewed
reasonix-source-event-log
Reasonix designates an append-only events JSONL file as transcript authority and keeps derived context, event-index, display-index, conflict, checkpoint, and job artifacts in separate sidecars.
- Agent
- Reasonix
- Snapshot
- reasonix-2026-08-10-source
- Reviewed
- 2026-08-10
EXPERIMENTS · EXERCISES
What has actually been tested?
Formal experiments are separate from course exercises. Exercises can validate the reference implementation but cannot replace Native evidence from a real agent.
s02-events-streamingobserve
Verify the streaming traceThree deltas produce three ordered events and the last is explicitly final.
python3 -m curriculum.golden verify s02-events-streamings02-events-streamingmodify
Test the streaming message contractDeltas remain replayable without polluting the next-turn message history.
python3 -m unittest curriculum.tests.test_vertical_slice.VerticalSliceTests.test_s02_streaming_becomes_events -vs07-session-replayobserve
Verify replay lineageThe same run produces a stable replay fingerprint and a branch at sequence 2.
python3 -m curriculum.golden verify s07-session-replays07-session-replaymodify
Test journal invariantsGapped sequences, mixed runs, and out-of-range forks are rejected without rewriting the parent log.
python3 -m unittest curriculum.tests.test_vertical_slice.VerticalSliceTests.test_s07_replays_and_branches -vs13-checkpoint-rollbackobserve
Verify the reversible changeThe trace records a clean checkpoint, a 1/1 diff, scoped rollback, and clean=true in order.
python3 -m curriculum.golden verify s13-checkpoint-rollbacks13-checkpoint-rollbackmodify
Test scoped rollbackOnly the explicit file is restored, escape paths are rejected, and final content returns to baseline.
python3 -m unittest curriculum.tests.test_vertical_slice.VerticalSliceTests.test_s13_rolls_back_only_the_reviewed_scoped_diff -v01
Which streaming payload fields can be portable without erasing provider-specific semantics?