refactor(runtime): derive Session transcripts from RuntimeEvents

apps/desktop/src/main/__tests__/runtime-host-client.test.ts

@@ -78,11 +78,6 @@ test('derives turn records from bounded contribution pages', async () => {
             firstSequence: 0,
             latestState: null,
             userPromptPreview: 'hello',
-            hasAssistantMessage: true,
-            hasAssistantOutput: true,
-            hasToolResult: false,
-            hasFailedToolResult: false,
-            hasAbortNote: false,
           }],
           nextPosition: 2,
         };
@@ -105,11 +100,6 @@ test('derives turn records from bounded contribution pages', async () => {
             },
           },
           userPromptPreview: null,
-          hasAssistantMessage: false,
-          hasAssistantOutput: false,
-          hasToolResult: true,
-          hasFailedToolResult: false,
-          hasAbortNote: false,
         }],
         nextPosition: null,
       };
@@ -124,7 +114,7 @@ test('derives turn records from bounded contribution pages', async () => {
     userPromptPreview: 'hello',
     status: 'completed',
     statusSource: 'recorded',
-    partialOutputRetained: true,
+    partialOutputRetained: false,
   }]);
   assert.deepEqual(positions, [0, 2]);
   await client.close();

apps/desktop/src/main/runtime-host-client.ts

@@ -1648,7 +1648,7 @@ export class DesktopRuntimeHostClient {
     }
     return [...contributions.values()]
       .sort((left, right) => left.firstSequence - right.firstSequence)
-      .map(projectSessionTurnContribution);
+      .flatMap((contribution) => projectSessionTurnContribution(contribution) ?? []);
   }
 
   async listSessionTurnLandmarks(

packages/cli/src/pi-transcript.ts

@@ -31,6 +31,7 @@ import type {
 } from '@maka/core/events';
 import {
   deriveTurnRecords,
+  isRuntimeSystemNoteKind,
   STEP_LIMIT_NOTICE_TEXT,
   type StoredMessage,
   type SystemNoteMessage,
@@ -1344,14 +1345,10 @@ function tokenDelta(before: number | undefined, after: number | undefined): numb
 }
 
 function systemNoteText(message: SystemNoteMessage): string | undefined {
+  // Retired kinds are still decoded off legacy transcript rows, and none of
+  // them ever had a line here worth reading.
+  if (!isRuntimeSystemNoteKind(message.kind)) return undefined;
   switch (message.kind) {
-    case 'session_start':
-    case 'session_resume':
-      return undefined;
-    case 'mode_change':
-      return 'Permission mode changed.';
-    case 'model_change':
-      return 'Model changed.';
     case 'context_compacted':
       return 'Context compacted to keep this task within the model window.';
     case 'context_compaction_failed_open':
@@ -1408,10 +1405,6 @@ function systemNoteText(message: SystemNoteMessage): string | undefined {
     }
     case 'step_limit':
       return STEP_LIMIT_NOTICE_TEXT;
-    case 'error':
-      return 'Session recorded an error.';
-    case 'abort':
-      return 'Session was stopped.';
   }
 }
 

packages/core/src/runtime-event.ts

@@ -61,7 +61,11 @@ import {
   type OrchestrationMode,
 } from './orchestration.js';
 import { isToolMode, type ToolMode } from './tool-mode.js';
-import type { PersistedBackendKind } from './session.js';
+import {
+  isRuntimeSystemNoteKind,
+  type PersistedBackendKind,
+  type RuntimeSystemNoteKind,
+} from './session.js';
 import { decodeTurnOrigin, type TurnOrigin } from './turn-origin.js';
 import type { UserQuestionRequest } from './user-question.js';
 import {
@@ -217,6 +221,22 @@ export interface RuntimeEventFunctionResponseContent {
   modelProjection?: DurableToolResultProjection;
 }
 
+/**
+ * A note the runtime wrote about what happened during an invocation — context
+ * was compacted, the step cap was reached, the turn was aborted.
+ *
+ * It is a transcript row, not a model-facing payload: nothing replays it to a
+ * provider. It lives here because it is a fact of the invocation, and the
+ * invocation's events are the only record of those. Notes that happen between
+ * turns have no invocation, so they stay Session transcript rows.
+ */
+export interface RuntimeEventSystemNoteContent {
+  kind: 'system_note';
+  note: RuntimeSystemNoteKind;
+  /** Shape depends on `note`, exactly as it does on the transcript row. */
+  data?: unknown;
+}
+
 export interface RuntimeEventErrorContent {
   kind: 'error';
   code?: string;
@@ -337,6 +357,7 @@ export type RuntimeEventContent =
   | RuntimeEventFunctionCallContent
   | RuntimeEventFunctionResponseContent
   | RuntimeEventErrorContent
+  | RuntimeEventSystemNoteContent
   | RuntimeEventInvocationOpenedContent;
 
 export const RUNTIME_EVENT_CONTENT_KINDS = [
@@ -345,6 +366,7 @@ export const RUNTIME_EVENT_CONTENT_KINDS = [
   'function_call',
   'function_response',
   'error',
+  'system_note',
   'invocation_opened',
 ] as const;
 export type RuntimeEventContentKind = (typeof RUNTIME_EVENT_CONTENT_KINDS)[number];
@@ -365,6 +387,12 @@ export interface RuntimeEventTokenUsage extends TokenUsageFields {}
  */
 export interface RuntimeEventPermissionDecision extends PermissionResponse {
   toolName?: string;
+  /**
+   * What the prompt told the user they were approving. Normally read off the
+   * paired request; carried here when the decision is the only surviving
+   * evidence that the prompt happened.
+   */
+  hint?: string;
 }
 
 export const TOOL_BOUNDARY_PROTOCOL_V1 = 't1_after_preflight_v1' as const;
@@ -696,6 +724,10 @@ const ERROR_CONTENT_SHAPE = defineObjectShape<RuntimeEventErrorContent>()(
   ['kind', 'message'],
   ['code', 'reason', 'details'],
 );
+const SYSTEM_NOTE_CONTENT_SHAPE = defineObjectShape<RuntimeEventSystemNoteContent>()(
+  ['kind', 'note'],
+  ['data'],
+);
 const INVOCATION_OPENED_CONTENT_SHAPE = defineObjectShape<RuntimeEventInvocationOpenedContent>()(
   ['kind', 'protocol', 'route', 'configuration', 'root', 'source'],
   ['lineage'],
@@ -803,7 +835,7 @@ const PERMISSION_CLOSURE_ACCEPTED_SHAPE =
   defineObjectShape<RuntimeEventPermissionClosureAccepted>()(['requestId', 'reason'], []);
 const RUNTIME_PERMISSION_DECISION_SHAPE = defineObjectShape<RuntimeEventPermissionDecision>()(
   ['requestId', 'decision'],
-  ['rememberForTurn', 'reviewer', 'rationale', 'riskLevel', 'toolName'],
+  ['rememberForTurn', 'reviewer', 'rationale', 'riskLevel', 'toolName', 'hint'],
 );
 const UTF8 = new TextEncoder();
 const RUNTIME_TOOL_DISPATCH_SHAPE = defineObjectShape<RuntimeEventToolDispatch>()(
@@ -1022,6 +1054,12 @@ function isRuntimeEventContent(value: unknown): value is RuntimeEventContent {
         typeof value.message === 'string' &&
         (value.details === undefined || isStringArray(value.details) || isRecord(value.details))
       );
+    case 'system_note':
+      return (
+        hasExactShape(value, SYSTEM_NOTE_CONTENT_SHAPE) &&
+        typeof value.note === 'string' &&
+        isRuntimeSystemNoteKind(value.note)
+      );
     case 'invocation_opened':
       return isRuntimeInvocationOpened(value);
     default:
@@ -1266,7 +1304,8 @@ function isRuntimeEventPermissionDecision(value: unknown): value is RuntimeEvent
     (value.toolName === undefined ||
       (typeof value.toolName === 'string' &&
         value.toolName.length > 0 &&
-        UTF8.encode(value.toolName).byteLength <= INTERACTION_TOOL_NAME_MAX_BYTES))
+        UTF8.encode(value.toolName).byteLength <= INTERACTION_TOOL_NAME_MAX_BYTES)) &&
+    isOptionalString(value.hint)
   );
 }
 
@@ -1485,6 +1524,7 @@ export function runtimeEventHasModelVisibleContent(event: RuntimeEvent): boolean
     case 'function_response':
       return true;
     case 'error':
+    case 'system_note':
     case 'invocation_opened':
       return false;
   }

packages/core/src/session.ts

@@ -283,7 +283,7 @@ export interface SessionHeader {
   /** Immutable Connection entity identity. Optional only on legacy Session records. */
   llmConnectionId?: string;
   llmConnectionSlug: string;
-  /** True after first UserMessage is flushed. Storage self-heals (§5.2). */
+  /** True once the Session's first UserMessage is durable. One-way. */
   connectionLocked: boolean;
   /** Sticky session default model id, captured when the session is created. */
   model: string;
@@ -789,20 +789,12 @@ export function userFacingText(message: Pick<UserMessage, 'text' | 'displayText'
   return message.displayText ?? message.text;
 }
 
-const USER_VISIBLE_SESSION_SYSTEM_NOTES = new Set([
-  'context_compacted',
-  'context_compaction_failed_open',
-  'context_provider_dropping',
-  'context_window_suggestion',
-  'context_window_overrun',
-  'context_reported_window_exceeded',
-  'context_overflow_after_compaction',
-  'step_limit',
-]);
-
-/** Closed policy for system notes that are part of the user-visible transcript. */
+/**
+ * Closed policy for system notes that are part of the user-visible transcript:
+ * exactly the notes the runtime writes.
+ */
 export function isUserVisibleSessionSystemNote(kind: string): boolean {
-  return USER_VISIBLE_SESSION_SYSTEM_NOTES.has(kind);
+  return isRuntimeSystemNoteKind(kind);
 }
 
 export interface AssistantMessage {
@@ -1147,27 +1139,49 @@ export interface TurnRecord {
   partialOutputRetained: boolean;
 }
 
+/**
+ * The notes the runtime writes: things that happened inside one invocation and
+ * are part of what that invocation did. Their record is its RuntimeEvent ledger.
+ */
+export const RUNTIME_SYSTEM_NOTE_KINDS = [
+  'context_compacted',
+  'context_compaction_failed_open',
+  'context_provider_dropping',
+  'context_window_suggestion',
+  'context_window_overrun',
+  'context_reported_window_exceeded',
+  'context_overflow_after_compaction',
+  'step_limit',
+] as const;
+
+/**
+ * Notes only legacy transcripts carry, still decoded so those rows stay
+ * readable. Nothing writes them: the Session header and the invocation's
+ * opening and terminal facts already own what each of them said.
+ */
+export const RETIRED_SYSTEM_NOTE_KINDS = [
+  'session_start',
+  'session_resume',
+  'mode_change',
+  'model_change',
+  'error',
+  'abort',
+] as const;
+
+export type RuntimeSystemNoteKind = (typeof RUNTIME_SYSTEM_NOTE_KINDS)[number];
+export type SystemNoteKind = RuntimeSystemNoteKind | (typeof RETIRED_SYSTEM_NOTE_KINDS)[number];
+
+export function isRuntimeSystemNoteKind(kind: string): kind is RuntimeSystemNoteKind {
+  return (RUNTIME_SYSTEM_NOTE_KINDS as readonly string[]).includes(kind);
+}
+
 export interface SystemNoteMessage {
   type: 'system_note';
   id: string;
-  /** Session-level notes omit turnId. */
+  /** Retired session-level notes omit turnId. */
   turnId?: string;
   ts: number;
-  kind:
-    | 'session_start'
-    | 'session_resume'
-    | 'mode_change'
-    | 'model_change'
-    | 'context_compacted'
-    | 'context_compaction_failed_open'
-    | 'context_provider_dropping'
-    | 'context_window_suggestion'
-    | 'context_window_overrun'
-    | 'context_reported_window_exceeded'
-    | 'context_overflow_after_compaction'
-    | 'step_limit'
-    | 'error'
-    | 'abort';
+  kind: SystemNoteKind;
   /**
    * Shape depends on `kind`. `context_compaction_failed_open` carries
    * `{ failOpenReason?: string }` — the reason the fold was refused (e.g.
@@ -1408,21 +1422,9 @@ const ASSISTANT_THINKING_SHAPE = defineObjectShape<AssistantThinking>()(
   ['text'],
   ['signature', 'providerOptions', 'parts'],
 );
-const SYSTEM_NOTE_KINDS = new Set([
-  'session_start',
-  'session_resume',
-  'mode_change',
-  'model_change',
-  'context_compacted',
-  'context_compaction_failed_open',
-  'context_provider_dropping',
-  'context_window_suggestion',
-  'context_window_overrun',
-  'context_reported_window_exceeded',
-  'context_overflow_after_compaction',
-  'step_limit',
-  'error',
-  'abort',
+const SYSTEM_NOTE_KINDS = new Set<string>([
+  ...RUNTIME_SYSTEM_NOTE_KINDS,
+  ...RETIRED_SYSTEM_NOTE_KINDS,
 ]);
 
 export function decodeCanonicalMessage(value: unknown): StoredMessage {

packages/runtime-host/src/__tests__/client-capability-admission-integration.test.ts

@@ -150,7 +150,6 @@ test('cancels managed approval owners and joiners with the canonical provider id
         header: sessionHeader(),
         connection: llmConnection(),
         modelId: 'model-1',
-        appendMessage: async () => undefined,
         readExecutionBoundary: async () =>
           createManagedExecutionBoundary(createWorkspaceWritePermissionProfile(), 0),
         newId: nextId(),

packages/runtime-host/src/__tests__/execution-composition.test.ts

@@ -65,6 +65,7 @@ import {
   stopReplacedWorkHubRoot,
 } from '../server/execution-composition.js';
 import { waitFor as pollFor } from '@maka/core/test-only/async-primitives';
+import { readLedgerMessages } from './fixtures/ledger-transcript.js';
 
 const require = createRequire(import.meta.url);
 const FAKE_CONNECTION_ID = 'bbbbbbbb-bbbb-4bbb-8bbb-bbbbbbbbbbbb';
@@ -462,6 +463,9 @@ test('production recovery preserves legacy Automation history and closes an orph
     const composition = await createExecutionRuntimeHostComposition(compositionContext(owner));
     try {
       await composition.recover();
+      // The legacy transcript itself, as the converter reads it: recovery must
+      // leave a pre-ledger Automation's origin intact for the import that
+      // follows on the Session's first read.
       const history = await stores.sessionStore.readMessages(historical.id);
       assert.deepEqual(history[0]?.type === 'user' ? history[0].origin : undefined, {
         kind: 'legacy_automation',
@@ -2019,7 +2023,7 @@ async function assertUniqueGraphExecutionFacts(
 ): Promise<void> {
   const [runs, messages, runtimeEvents] = await Promise.all([
     stores.runtimeEventStore.listSessionInvocations(claim.targetSessionId),
-    stores.sessionStore.readMessages(claim.targetSessionId),
+    readLedgerMessages(stores.runtimeEventStore, claim.targetSessionId),
     stores.runtimeEventStore.readImmutableRuntimeEvents(claim.targetSessionId, claim.targetRunId),
   ]);
   assert.deepEqual(

packages/runtime-host/src/__tests__/execution-host-queue.test.ts

@@ -90,6 +90,7 @@ import {
 } from '../protocol/index.js';
 import { SessionAdmissionGate } from '../server/session-admission-gate.js';
 import { FramedTransport } from '../transport/framed-transport.js';
+import { readLedgerMessages } from './fixtures/ledger-transcript.js';
 
 import {
   CONNECTION_EFFECT_MODEL_IDS,
@@ -773,7 +774,7 @@ test('startup recovery canonically closes pending linked child admissions withou
           assert.equal(terminal.fact.failureClass, 'app_restarted');
         }
         const userMessages: StoredMessage[] = (
-          await stores.sessionStore.readMessages(recovered.sessionId)
+          await readLedgerMessages(stores.runtimeEventStore, recovered.sessionId)
         ).filter((message) => message.type === 'user' && message.turnId === recovered.turnId);
         assert.equal(userMessages.length, recovered.kind === 'linked_child_provider_retry' ? 0 : 1);
         if (recovered.kind !== 'linked_child_provider_retry') {