diff --git a/extensions/codex/src/app-server/compact.ts b/extensions/codex/src/app-server/compact.ts
index cd90f7557d8..6d8900fa11d 100644
--- a/extensions/codex/src/app-server/compact.ts
+++ b/extensions/codex/src/app-server/compact.ts
@@ -47,7 +47,6 @@ export async function maybeCompactCodexAppServerSession(
         sessionId: params.sessionId,
         sessionKey: params.sessionKey,
         transcriptScope: { agentId: params.agentId ?? "main", sessionId: params.sessionId },
-        transcriptLocator: params.sessionId,
         tokenBudget: params.contextTokenBudget,
         currentTokenCount: params.currentTokenCount,
         compactionTarget: params.trigger === "manual" ? "threshold" : "budget",
@@ -73,7 +72,6 @@ export async function maybeCompactCodexAppServerSession(
           sessionId: params.sessionId,
           sessionKey: params.sessionKey,
           transcriptScope: { agentId: params.agentId ?? "main", sessionId: params.sessionId },
-          transcriptLocator: params.sessionId,
           reason: "compaction",
           runtimeContext: params.contextEngineRuntimeContext,
           config: params.config,
diff --git a/extensions/codex/src/app-server/run-attempt.ts b/extensions/codex/src/app-server/run-attempt.ts
index 46e1494d868..7fd4dfbad4d 100644
--- a/extensions/codex/src/app-server/run-attempt.ts
+++ b/extensions/codex/src/app-server/run-attempt.ts
@@ -544,7 +544,7 @@ export async function runCodexAppServerAttempt(
       runId: params.runId,
     },
   });
-  const hadSessionFile = hasSqliteSessionTranscriptEvents({
+  const hadTranscript = hasSqliteSessionTranscriptEvents({
     agentId: sessionAgentId,
     sessionId: params.sessionId,
   });
@@ -565,12 +565,11 @@ export async function runCodexAppServerAttempt(
   };
   if (activeContextEngine) {
     await bootstrapHarnessContextEngine({
-      hadTranscriptLocator: hadSessionFile,
+      hadTranscript,
       contextEngine: activeContextEngine,
       sessionId: params.sessionId,
       sessionKey: sandboxSessionKey,
       transcriptScope: { agentId: sessionAgentId, sessionId: params.sessionId },
-      transcriptLocator: params.sessionId,
       runtimeContext: buildHarnessContextEngineRuntimeContext({
         attempt: runtimeParams,
         workspaceDir: effectiveWorkspace,
@@ -1512,7 +1511,6 @@ export async function runCodexAppServerAttempt(
         sessionIdUsed: params.sessionId,
         sessionKey: sandboxSessionKey,
         transcriptScope: { agentId: sessionAgentId, sessionId: params.sessionId },
-        transcriptLocator: params.sessionId,
         messagesSnapshot: finalMessages,
         prePromptMessageCount,
         tokenBudget: params.contextTokenBudget,
diff --git a/src/agents/harness/context-engine-lifecycle.ts b/src/agents/harness/context-engine-lifecycle.ts
index 10b8907132c..7e011222c36 100644
--- a/src/agents/harness/context-engine-lifecycle.ts
+++ b/src/agents/harness/context-engine-lifecycle.ts
@@ -19,12 +19,12 @@ export type HarnessContextEngine = ContextEngine;
  * Run optional bootstrap + bootstrap maintenance for a harness-owned context engine.
  */
 export async function bootstrapHarnessContextEngine(params: {
-  hadTranscriptLocator: boolean;
+  hadTranscript: boolean;
   contextEngine?: HarnessContextEngine;
   sessionId: string;
   sessionKey?: string;
   transcriptScope?: ContextEngineTranscriptScope;
-  transcriptLocator: string;
+  transcriptLocator?: string;
   sessionManager?: unknown;
   runtimeContext?: ContextEngineRuntimeContext;
   runMaintenance?: typeof runHarnessContextEngineMaintenance;
@@ -32,7 +32,7 @@ export async function bootstrapHarnessContextEngine(params: {
   warn: (message: string) => void;
 }): Promise<void> {
   if (
-    !params.hadTranscriptLocator ||
+    !params.hadTranscript ||
     !(params.contextEngine?.bootstrap || params.contextEngine?.maintain)
   ) {
     return;
@@ -103,7 +103,7 @@ export async function finalizeHarnessContextEngineTurn(params: {
   sessionIdUsed: string;
   sessionKey?: string;
   transcriptScope?: ContextEngineTranscriptScope;
-  transcriptLocator: string;
+  transcriptLocator?: string;
   messagesSnapshot: AgentMessage[];
   prePromptMessageCount: number;
   tokenBudget?: number;
@@ -236,7 +236,7 @@ export async function runHarnessContextEngineMaintenance(params: {
   sessionId: string;
   sessionKey?: string;
   transcriptScope?: ContextEngineTranscriptScope;
-  transcriptLocator: string;
+  transcriptLocator?: string;
   reason: "bootstrap" | "compaction" | "turn";
   sessionManager?: unknown;
   runtimeContext?: ContextEngineRuntimeContext;
diff --git a/src/agents/pi-embedded-runner/context-engine-maintenance.ts b/src/agents/pi-embedded-runner/context-engine-maintenance.ts
index 019d62f4983..63bcf934c10 100644
--- a/src/agents/pi-embedded-runner/context-engine-maintenance.ts
+++ b/src/agents/pi-embedded-runner/context-engine-maintenance.ts
@@ -49,7 +49,7 @@ type DeferredTurnMaintenanceScheduleParams = {
   sessionId: string;
   sessionKey: string;
   transcriptScope?: ContextEngineTranscriptScope;
-  transcriptLocator: string;
+  transcriptLocator?: string;
   sessionManager?: Parameters<typeof rewriteTranscriptEntriesInSessionManager>[0]["sessionManager"];
   runtimeContext?: ContextEngineRuntimeContext;
   agentId?: string;
@@ -281,7 +281,7 @@ export function buildContextEngineMaintenanceRuntimeContext(params: {
   sessionId: string;
   sessionKey?: string;
   transcriptScope?: ContextEngineTranscriptScope;
-  transcriptLocator: string;
+  transcriptLocator?: string;
   sessionManager?: Parameters<typeof rewriteTranscriptEntriesInSessionManager>[0]["sessionManager"];
   runtimeContext?: ContextEngineRuntimeContext;
   agentId?: string;
@@ -344,7 +344,7 @@ async function executeContextEngineMaintenance(params: {
   sessionId: string;
   sessionKey?: string;
   transcriptScope?: ContextEngineTranscriptScope;
-  transcriptLocator: string;
+  transcriptLocator?: string;
   reason: "bootstrap" | "compaction" | "turn";
   sessionManager?: Parameters<typeof rewriteTranscriptEntriesInSessionManager>[0]["sessionManager"];
   runtimeContext?: ContextEngineRuntimeContext;
@@ -392,7 +392,7 @@ async function runDeferredTurnMaintenanceWorker(params: {
   sessionId: string;
   sessionKey: string;
   transcriptScope?: ContextEngineTranscriptScope;
-  transcriptLocator: string;
+  transcriptLocator?: string;
   sessionManager?: Parameters<typeof rewriteTranscriptEntriesInSessionManager>[0]["sessionManager"];
   runtimeContext?: ContextEngineRuntimeContext;
   agentId?: string;
@@ -659,7 +659,7 @@ export async function runContextEngineMaintenance(params: {
   sessionId: string;
   sessionKey?: string;
   transcriptScope?: ContextEngineTranscriptScope;
-  transcriptLocator: string;
+  transcriptLocator?: string;
   reason: "bootstrap" | "compaction" | "turn";
   sessionManager?: Parameters<typeof rewriteTranscriptEntriesInSessionManager>[0]["sessionManager"];
   runtimeContext?: ContextEngineRuntimeContext;
diff --git a/src/agents/pi-embedded-runner/run/attempt.spawn-workspace.context-engine.test.ts b/src/agents/pi-embedded-runner/run/attempt.spawn-workspace.context-engine.test.ts
index d38d1e0ed0c..493c2ce5e46 100644
--- a/src/agents/pi-embedded-runner/run/attempt.spawn-workspace.context-engine.test.ts
+++ b/src/agents/pi-embedded-runner/run/attempt.spawn-workspace.context-engine.test.ts
@@ -81,7 +81,7 @@ async function runBootstrap(
   overrides: Partial<Parameters<typeof runAttemptContextEngineBootstrap>[0]> = {},
 ) {
   await runAttemptContextEngineBootstrap({
-    hadTranscriptLocator: true,
+    hadTranscript: true,
     contextEngine,
     sessionId: embeddedSessionId,
     sessionKey,
diff --git a/src/agents/pi-embedded-runner/run/attempt.ts b/src/agents/pi-embedded-runner/run/attempt.ts
index 355cd7dc31a..6769c6b284e 100644
--- a/src/agents/pi-embedded-runner/run/attempt.ts
+++ b/src/agents/pi-embedded-runner/run/attempt.ts
@@ -1647,12 +1647,11 @@ export async function runEmbeddedAttempt(
       }
       const sessionTranscriptLocator = createSqliteSessionTranscriptLocator(sessionTranscriptScope);
       await runAttemptContextEngineBootstrap({
-        hadTranscriptLocator: hadTranscriptEvents,
+        hadTranscript: hadTranscriptEvents,
         contextEngine: activeContextEngine,
         sessionId: params.sessionId,
         sessionKey: params.sessionKey,
         transcriptScope: sessionTranscriptScope,
-        transcriptLocator: sessionTranscriptLocator,
         sessionManager,
         runtimeContext: buildAfterTurnRuntimeContext({
           attempt: params,
diff --git a/src/context-engine/legacy.ts b/src/context-engine/legacy.ts
index a8d7c730d4e..f64f619522d 100644
--- a/src/context-engine/legacy.ts
+++ b/src/context-engine/legacy.ts
@@ -56,7 +56,7 @@ export class LegacyContextEngine implements ContextEngine {
   async afterTurn(_params: {
     sessionId: string;
     sessionKey?: string;
-    transcriptLocator: string;
+    transcriptLocator?: string;
     messages: AgentMessage[];
     prePromptMessageCount: number;
     autoCompactionSummary?: string;
@@ -70,7 +70,7 @@ export class LegacyContextEngine implements ContextEngine {
   async compact(params: {
     sessionId: string;
     sessionKey?: string;
-    transcriptLocator: string;
+    transcriptLocator?: string;
     tokenBudget?: number;
     force?: boolean;
     currentTokenCount?: number;
diff --git a/src/context-engine/types.ts b/src/context-engine/types.ts
index a093057f725..77ef75b69c7 100644
--- a/src/context-engine/types.ts
+++ b/src/context-engine/types.ts
@@ -205,7 +205,7 @@ export interface ContextEngine {
     sessionId: string;
     sessionKey?: string;
     transcriptScope?: ContextEngineTranscriptScope;
-    transcriptLocator: string;
+    transcriptLocator?: string;
   }): Promise<BootstrapResult>;
 
   /**
@@ -218,7 +218,7 @@ export interface ContextEngine {
     sessionId: string;
     sessionKey?: string;
     transcriptScope?: ContextEngineTranscriptScope;
-    transcriptLocator: string;
+    transcriptLocator?: string;
     runtimeContext?: ContextEngineRuntimeContext;
   }): Promise<ContextEngineMaintenanceResult>;
 
@@ -253,7 +253,7 @@ export interface ContextEngine {
     sessionId: string;
     sessionKey?: string;
     transcriptScope?: ContextEngineTranscriptScope;
-    transcriptLocator: string;
+    transcriptLocator?: string;
     messages: AgentMessage[];
     /** Number of messages that existed before the prompt was sent. */
     prePromptMessageCount: number;
@@ -295,7 +295,7 @@ export interface ContextEngine {
     sessionId: string;
     sessionKey?: string;
     transcriptScope?: ContextEngineTranscriptScope;
-    transcriptLocator: string;
+    transcriptLocator?: string;
     tokenBudget?: number;
     /** Force compaction even below the default trigger threshold. */
     force?: boolean;