Distillation

Date: Sep 17, 2026

• 🔴 (08:37) User directed that a newer turn supersede stale incomplete rows and that the system “never resume an older assistant projection.”
• 🟡 (08:37) packages/core/src/session/context-epoch.ts defines SessionContextEpoch.initialize(...) and SessionContextEpoch.prepare(...); both require a SessionExecutionClaim.Claim, and return a baseline plus baselineSeq when preparation succeeds.
• 🟡 (08:37) SessionContextEpoch.prepareOnce(...) concurrently loads the current SystemContext.SystemContext, the stored SessionContextEpochTable row, and SessionHistory.latestCompaction(db, sessionID) using Effect.all(..., { concurrency: "unbounded" }).
• 🟡 (08:37) When no context epoch is stored, prepareOnce(...) runs SystemContext.initialize(value), inserts the generated baseline/snapshot under the execution claim, and returns { baseline: generation.baseline, baselineSeq }.
• 🟡 (08:37) Stored context snapshots are decoded with Schema.decodeUnknownEffect(SystemContext.Snapshot); decode failures become ContextSnapshotDecodeError({ sessionID, details: String(error) }).
• 🟡 (08:37) Context replacement is selected only when the latest compaction sequence exceeds stored.baseline_seq: replacementSeq = compaction !== undefined && compaction.seq > stored.baseline_seq ? compaction.seq : undefined. It then calls SystemContext.replace(value, snapshot); otherwise it calls SystemContext.reconcile(value, snapshot).
• 🟡 (08:37) For SystemContext results tagged "Unchanged" or "ReplacementBlocked", prepareOnce(...) retains { baseline: stored.baseline, baselineSeq: stored.baseline_seq }. For "ReplacementReady", it uses replacementSeq or EventV2.latestSequence(db, sessionID), persists the replacement, and returns the new generation’s baseline.
• 🟡 (08:37) A reconciled context update publishes SessionEvent.ContextUpdated with a fresh SessionMessage.ID, current DateTime, and result.text; its commit callback calls advance(db, sessionID, result.snapshot, claim).pipe(Effect.orDie), while the existing baseline and baseline_seq remain unchanged.
• 🟡 (08:37) SessionContextEpoch.initializeOnce(...) does nothing if an epoch already exists; otherwise it initializes the context and inserts the generated baseline/snapshot.
• 🟡 (08:37) SessionContextEpoch.reset(...) deletes the session’s row from SessionContextEpochTable.
• 🟡 (08:37) Context epoch insert(...), replace(...), and advance(...) perform writes through SessionExecutionClaim.transaction(...). insert(...) records session_id, baseline, snapshot, and baseline_seq; replace(...) updates all three context fields; advance(...) updates only snapshot. Missing rows after replace(...) or advance(...) cause Effect.die("Context Epoch not found").
• 🟡 (08:37) packages/core/src/session/message-updater.ts applies text stream events only to the owned assistant: "session.next.text.delta" appends to the latest matching text part, while "session.next.text.ended" replaces it with the final text.
• 🟡 (08:37) Tool projection lifecycle in packages/core/src/session/message-updater.ts: 1. "session.next.tool.input.started" appends a pending SessionMessage.AssistantTool with empty string input; 2. "session.next.tool.input.delta" is ignored; 3. "session.next.tool.input.ended" stores final input text while pending; 4. "session.next.tool.called" changes the tool to running with provider, time.ran, structured {}, and content []; 5. "session.next.tool.progress" replaces running structured/content progress; 6. "session.next.tool.success" creates completed state with input, structured data, content, outputPaths defaulting to [], and result; 7. "session.next.tool.failed" creates error state from pending or running state.
• 🟡 (08:37) Tool success/failure projection preserves prior provider metadata, stores result metadata as event.data.provider.metadata, and computes executed as event.data.provider.executed || match.provider?.executed === true. Failure preserves running structured/content data, uses {} and [] for pending tools, and converts string pending input to {}.
• 🟡 (08:37) Reasoning projection in packages/core/src/session/message-updater.ts appends a new empty SessionMessage.AssistantReasoning on "session.next.reasoning.started", concatenates deltas on "session.next.reasoning.delta", and on "session.next.reasoning.ended" sets final text, preserves the original creation time when available, records completion time, and updates providerMetadata when supplied.
• 🟡 (08:37) "session.next.compaction.ended" appends a SessionMessage.Compaction containing id, type: "compaction", event metadata, reason, summary text, retained recent text, and creation timestamp. Compaction started/delta, retry, and revert staged/cleared/committed events are no-ops in this updater.
• 🟡 (08:37) packages/core/src/session/projector.ts handles a committed revert by locating the boundary message sequence and dying with Revert boundary message not found: ${event.data.messageID} if absent; it deletes session messages with seq > boundary.seq, deletes session inputs whose admitted_seq or promoted_seq exceeds the boundary, then clears SessionTable.revert and updates time_updated.
• 🟡 (08:37) The global projector node is exported as makeGlobalNode({ name: "session-projector", layer, deps: [EventV2.node, Database.node] }).
• 🟡 (08:37) Event implementation files located during inspection were /tmp/opencode/session-recovery-v20-review/packages/core/src/event.ts and /tmp/opencode/session-recovery-v20-review/packages/core/src/session/event.ts.