Distillation

Date: Sep 17, 2026

• 🟡 (09:09) packages/core/src/session/context-epoch.ts defines SessionContextEpoch.initialize() and SessionContextEpoch.prepare(). Both accept a DatabaseService, SystemContext.SystemContext effect, sessionID, and SessionExecutionClaim.Claim; prepare() additionally accepts EventV2.Interface.
• 🟡 (09:09) SessionContextEpoch.prepareOnce() concurrently loads the current system context, stored context epoch, and SessionHistory.latestCompaction(db, sessionID) with { concurrency: "unbounded" }.
• 🟡 (09:09) When no context epoch is stored, prepareOnce() calls SystemContext.initialize(value), inserts the generated baseline/snapshot through the execution claim, and returns { baseline: generation.baseline, baselineSeq }.
• 🟡 (09:09) Stored context snapshots are decoded with Schema.decodeUnknownEffect(SystemContext.Snapshot); decode failures become ContextSnapshotDecodeError({ sessionID, details: String(error) }).
• 🟡 (09:09) A newer compaction replaces context reconciliation only when compaction.seq > stored.baseline_seq. In that case replacementSeq=compaction.seq and SystemContext.replace(value, snapshot) is used; otherwise SystemContext.reconcile(value, snapshot) is used.
• 🟡 (09:09) SessionContextEpoch.prepareOnce() handles reconciliation results as follows: "Unchanged" and "ReplacementBlocked" retain the stored baseline and baseline_seq; "ReplacementReady" replaces the epoch using replacementSeq or EventV2.latestSequence(db, sessionID); an update result publishes SessionEvent.ContextUpdated and commits advance(db, sessionID, result.snapshot, claim).
• 🟡 (09:09) SessionContextEpoch.initializeOnce() returns without work if the session epoch already exists; otherwise it initializes the context and inserts { session_id, baseline, snapshot, baseline_seq }.
• 🟡 (09:09) Context-epoch writes in insert(), replace(), and advance() are fenced through SessionExecutionClaim.transaction(db, claim, ...). replace() and advance() die with exact error "Context Epoch not found" if their update returns no row.
• 🟡 (09:09) SessionContextEpoch.reset() deletes the row from SessionContextEpochTable matching session_id.
• 🟡 (09:09) In packages/core/src/session.ts, V2Session.messages() paginates by SessionMessageTable.seq: default cursor direction is "next", default requested order is "desc", "previous" reverses query order and then reverses returned rows, and an unknown cursor message ID returns [].
• 🟡 (09:09) V2Session.prompt() is uninterruptible. It resolves the prompt, defaults messageID to SessionMessage.ID.create() and delivery to "steer", admits it through SessionInput.admit() with requestExecution: input.resume !== false, maps SessionInput.LifecycleConflict defects to PromptConflictError, checks SessionInput.equivalent(admission.admitted, expected), and calls execution.wake() only when admission.shouldWake.
• 🟡 (09:09) resolvePrompt() preserves text, agents, and files; file MIME type comes from a data URI when available, otherwise "application/x-directory" for paths ending in /, otherwise FSUtil.mimeType(target).
• 🟡 (09:09) V2Session.shell(), V2Session.skill(), V2Session.compact(), and V2Session.wait() currently fail with OperationUnavailableError using operations "shell", "skill", "compact", and "wait" respectively.
• 🟡 (09:09) V2Session.switchAgent() publishes SessionEvent.AgentSwitched. V2Session.switchModel() publishes SessionEvent.ModelSwitched unless provider ID, model ID, and normalized variant already match; an absent variant is normalized to "default".
• 🟡 (09:09) V2Session.resume() verifies the session, calls SessionInput.requestPendingExecution(db, events, sessionID), then execution.resume(sessionID). V2Session.interrupt() runs execution.interrupt(sessionID) uninterruptibly.
• 🟡 (09:09) V2Session.revert exposes stage, clear, and commit: stage supplies Database.Service, EventV2.Service, and the session location; clear supplies EventV2.Service and the location; commit supplies EventV2.Service.
• 🟡 (09:09) The global SessionV2.node depends on Database.node, EventV2.node, ProjectV2.node, SessionExecution.node, SessionStore.node, LocationServiceMap.node, and SessionProjector.node.
• 🔴 (09:09) User directed that processes which never serve the HTTP application—specifically CLI processes and scripts—must not pay its module-load cost; serving construction should remain lazy.
• 🟡 (09:09) In packages/opencode/src/server/routes/instance/httpapi/server.ts, routes is created with createRoutes(), while webHandler is wrapped in lazy(() => HttpRouter.toWebHandler(...)) with disableLogger: true, memoMap, and disposeMiddleware.
• 🟡 (09:09) packages/opencode/src/server/routes/instance/httpapi/server.ts binds SessionExecution.node to SessionExecutionLocal.node. Observability.layer must remain the final Layer.provideMerge() because later-provided layers build beneath earlier ones; otherwise eagerly forked fibers such as the ModelsDev background refresh capture Effect’s default stdout logger and corrupt the TUI (#34730).
• 🟡 (09:10) packages/server/src/routes.ts defines applicationServices with Database.node, EventV2.node, httpClient, ToolOutputStore.cleanupNode, SessionV2.node, SessionRecovery.node, PermissionSaved.node, PtyTicket.node, Credential.node, PtyEnvironment.node, and LocationServiceMap.node.
• 🟡 (09:10) packages/server/src/routes.ts builds application services with AppNodeBuilder.build(applicationServices, [[SessionExecution.node, SessionExecutionLocal.node]]), so the server currently uses local session execution.
• 🟡 (09:10) createRoutes(password?) configures username "opencode" and uses Option.some(password) when a password is supplied; otherwise it uses ServerAuth.Config.layer. createEmbeddedRoutes() configures username "opencode" with Option.none().
• 🟡 (09:10) Server route assembly uses OpenAPI path /openapi.json and provides, in order, handlers, sessionLocationLayer, locationLayer, authorizationLayer, schemaErrorLayer, authentication, and the built service layer. Its webHandler() adds HttpServer.layerServices and sets disableLogger: true.
• 🟡 (09:10) packages/core/schema.json is SQLite schema version "7" with ID 3bc49670-06d1-4eba-9a45-8c8128bdcf6f and previous ID f14a9b18-8207-487e-a3d3-227e629ba9ad. Visible table entries include workspace, data_migration, account_state, account, control_account, credential, event_sequence, event, permission, project_directory, project, message, and part.