diff --git a/src/acp/control-plane/manager.core.ts b/src/acp/control-plane/manager.core.ts
index 9ce3ce610fe..d4c52f3d534 100644
--- a/src/acp/control-plane/manager.core.ts
+++ b/src/acp/control-plane/manager.core.ts
@@ -357,19 +357,15 @@ export class AcpSessionManager {
         state: "idle",
         lastActivityAt: Date.now(),
       };
+
+      let persisted: SessionEntry | null = null;
       try {
-        const persisted = await this.writeSessionMeta({
+        persisted = await this.writeSessionMeta({
           cfg: input.cfg,
           sessionKey,
           mutate: () => meta,
           failOnError: true,
         });
-        if (!persisted?.acp) {
-          throw new AcpRuntimeError(
-            "ACP_SESSION_INIT_FAILED",
-            `Could not persist ACP metadata for ${sessionKey}.`,
-          );
-        }
       } catch (error) {
         await runtime
           .close({
@@ -383,6 +379,24 @@ export class AcpSessionManager {
           });
         throw error;
       }
+
+      if (!persisted?.acp) {
+        await runtime
+          .close({
+            handle,
+            reason: "init-meta-failed",
+          })
+          .catch((closeError) => {
+            logVerbose(
+              `acp-manager: cleanup close failed after metadata write error for ${sessionKey}: ${String(closeError)}`,
+            );
+          });
+
+        throw new AcpRuntimeError(
+          "ACP_SESSION_INIT_FAILED",
+          `Could not persist ACP metadata for ${sessionKey}.`,
+        );
+      }
       this.setCachedRuntimeState(sessionKey, {
         runtime,
         handle,