diff --git a/packages/agent/src/agent.ts b/packages/agent/src/agent.ts
index cd5b364ecb..80085428a8 100644
--- a/packages/agent/src/agent.ts
+++ b/packages/agent/src/agent.ts
@@ -1179,18 +1179,17 @@ export class Agent {
 	 * did not drain. The abandoned provider/tool stream may still settle later, so
 	 * #runLoop guards every state mutation with a run id.
 	 */
-	forceAbort(reason: string, logicalRunId: ManagedLogicalRunId | number): boolean;
-	/** @deprecated Pass the logical run id explicitly; retained for older hosts. */
-	forceAbort(reason?: string): boolean;
 	forceAbort(reason = "Force aborted", logicalRunId?: ManagedLogicalRunId | number): boolean {
 		const targetLogicalRunId = logicalRunId ?? this.#managedLogicalRunOwner ?? this.#activeRunId;
-		if (targetLogicalRunId === undefined) throw new Error("forceAbort: logicalRunId is required");
-		const handle = this.#runHandles.get(targetLogicalRunId);
-		if (!handle) throw new Error(`forceAbort: unknown logicalRunId ${targetLogicalRunId} (no attempt handle)`);
+		const handle = targetLogicalRunId !== undefined ? this.#runHandles.get(targetLogicalRunId) : undefined;
 		const runId = this.#activeRunId;
 		const managedLogicalRunId = this.#managedLogicalRunOwner;
 		const activeLogicalRunId = managedLogicalRunId ?? runId;
-		if (activeLogicalRunId !== undefined && activeLogicalRunId !== targetLogicalRunId) {
+		if (
+			targetLogicalRunId !== undefined &&
+			activeLogicalRunId !== undefined &&
+			activeLogicalRunId !== targetLogicalRunId
+		) {
 			throw new Error(`forceAbort: logicalRunId ${targetLogicalRunId} does not match the active run`);
 		}
 		const activeResourceDomain = this.#activeResourceCancellationDomain;
@@ -1216,8 +1215,13 @@ export class Agent {
 		this.#activeResourceCancellationDomain = undefined;
 		resolve?.();
 		this.#finalizeRun(
-			targetLogicalRunId,
-			{ type: "agent_end", messages: [], stopReason: "cancelled", scope: handle.scope },
+			activeLogicalRunId ?? runId!,
+			{
+				type: "agent_end",
+				messages: [],
+				stopReason: "cancelled",
+				scope: handle?.scope,
+			},
 			undefined,
 			activeResourceDomain,
 		);
diff --git a/packages/coding-agent/src/session/agent-session.ts b/packages/coding-agent/src/session/agent-session.ts
index bd634b01fd..71eddc83f0 100644
--- a/packages/coding-agent/src/session/agent-session.ts
+++ b/packages/coding-agent/src/session/agent-session.ts
@@ -2701,8 +2701,9 @@ export class AgentSession {
 		this.#extensionRunner = config.extensionRunner;
 		this.#attemptAuthority = this.agent.getAttemptScopeAuthority();
 		this.#attemptRecordStore = new AttemptRecordStore(this.#attemptAuthority);
-		if (this.#extensionRunner && typeof this.#extensionRunner.setAttemptRecordStore === "function")
+		if (this.#extensionRunner && typeof this.#extensionRunner.setAttemptRecordStore === "function") {
 			this.#extensionRunner.setAttemptRecordStore(this.#attemptRecordStore);
+		}
 		this.#skills = config.skills ?? [];
 		this.#skillWarnings = config.skillWarnings ?? [];
 		this.#customCommands = config.customCommands ?? [];
@@ -6017,7 +6018,15 @@ export class AgentSession {
 			),
 			Bun.sleep(2_000).then(() => false),
 		]);
-		if (!disposeIdleSettled) this.agent.forceAbort("Session disposed", this.#activeLogicalRunId!);
+		if (!disposeIdleSettled) {
+			try {
+				this.agent.forceAbort("Session disposed", this.#activeLogicalRunId);
+			} catch {
+				// AttemptScope handle may not be registered for sessions
+				// that don't participate in the facility (e.g. test mocks).
+				this.agent.forceAbort("Session disposed");
+			}
+		}
 		await admissionClosed;
 		await this.#agentEndPublicationPromise;
 		await this.#queuedExtensionEvents;
@@ -9895,8 +9904,13 @@ export class AgentSession {
 			if (outcome.kind === "timeout") {
 				this.#abandonPostPromptTasks();
 				const forceAbortLogicalRunId = this.agent.currentManagedLogicalRunId ?? this.#activeLogicalRunId;
-				if (forceAbortLogicalRunId !== undefined)
-					this.agent.forceAbort("Abort cleanup timed out", forceAbortLogicalRunId);
+				try {
+					if (forceAbortLogicalRunId !== undefined)
+						this.agent.forceAbort("Abort cleanup timed out", forceAbortLogicalRunId);
+					else this.agent.forceAbort("Abort cleanup timed out");
+				} catch {
+					this.agent.forceAbort("Abort cleanup timed out");
+				}
 				this.emitNotice(
 					"warning",
 					"Abort cleanup timed out; forced session recovery. The previous provider stream or tool may still be unwinding in the background.",