diff --git a/docs/gateway/config-agents.md b/docs/gateway/config-agents.md
index f7736ce50162..091211d16bf7 100644
--- a/docs/gateway/config-agents.md
+++ b/docs/gateway/config-agents.md
@@ -589,7 +589,7 @@ Selects the agent whose model and credentials own ambient OpenClaw system-agent
 }
 ```
 
-Delegated consults with a requesting agent keep that requester as their owner. When `agentId` is absent, a sole configured agent resolves implicitly; ambient consults in a multi-agent fleet fail with an actionable error. Upgrade-only ownership lives at `agents.defaults.authInheritance.agentId` for inherited credentials and `agents.defaults.sessionStore.agentId` for unscoped rows in a fixed `session.store`.
+Delegated consults with a requesting agent keep that requester as their owner. When `agentId` is absent, a sole configured agent resolves implicitly; ambient consults in a multi-agent fleet fail with an actionable error. Upgrade-only ownership lives at `agents.defaults.authInheritance.agentId` for inherited credentials and `agents.defaults.sessionStore.agentId` for retired `main` session rows or unscoped rows in a fixed `session.store`.
 
 ### `agents.defaults.compaction`
 
diff --git a/docs/gateway/doctor.md b/docs/gateway/doctor.md
index defec1fa8ce2..d0fa776509b0 100644
--- a/docs/gateway/doctor.md
+++ b/docs/gateway/doctor.md
@@ -415,7 +415,7 @@ That stages grounded durable candidates into the short-term dreaming store while
 
     These migrations are best-effort and idempotent; doctor emits warnings when it leaves any legacy folders behind as backups. The Gateway/CLI also auto-migrates the legacy sessions + agent dir on startup so history/auth/models land in the per-agent path without a manual doctor run. WhatsApp auth is intentionally only migrated via `openclaw doctor`. Talk provider/provider-map normalization compares by structural equality, so key-order-only diffs no longer trigger repeat no-op `doctor --fix` changes.
 
-    When an explicit roster no longer contains `main`, OpenClaw migrates durable `agent:main:*` SQLite rows only if the replacement owner is unambiguous: the sole roster member or the configured fixed-store owner in `agents.defaults.sessionStore.agentId`. Conflicting canonical or alias rows are preserved during startup and reported with a Doctor hint. `openclaw doctor --fix` first imports any legacy JSON session store, then keeps the winning canonical claim and renames each losing claim to `agent:<owner>:legacy-main-conflict-<n>` in its original database. Quarantine changes only the key; the entry and full transcript remain available for inspection or archival.
+    When an explicit roster no longer contains `main`, OpenClaw migrates durable `agent:main:*` SQLite rows only if the replacement owner is unambiguous: the sole roster member or the configured upgrade owner in `agents.defaults.sessionStore.agentId`. The explicit owner works for both per-agent and fixed session stores; fixed-store runtime ownership remains scoped to that physical store. Conflicting canonical or alias rows are preserved during startup and reported with a Doctor hint. `openclaw doctor --fix` first imports any legacy JSON session store, then keeps the winning canonical claim and renames each losing claim to `agent:<owner>:legacy-main-conflict-<n>` in its original database. Quarantine changes only the key; the entry and full transcript remain available for inspection or archival.
 
   </Accordion>
   <Accordion title="3a. Legacy plugin manifest migrations">
diff --git a/src/config/schema.help.core.ts b/src/config/schema.help.core.ts
index 510e697a445c..d4b5e7bbc154 100644
--- a/src/config/schema.help.core.ts
+++ b/src/config/schema.help.core.ts
@@ -338,9 +338,9 @@ export const CORE_FIELD_HELP: Record<string, string> = {
   "agents.defaults.authInheritance.agentId":
     "Agent whose legacy credential store remains the inheritance source after default-marker retirement. Written automatically during upgrade when the former owner was not main.",
   "agents.defaults.sessionStore":
-    "Upgrade compatibility owner for a fixed legacy session store until its SQLite database records ownership.",
+    "Upgrade compatibility owner for retired main-agent rows and fixed legacy session stores.",
   "agents.defaults.sessionStore.agentId":
-    "Agent that owns unscoped rows in a fixed legacy session store after default-marker retirement. Written automatically during upgrade when the former owner was not main or the sole agent.",
+    "Agent that owns retired main-agent rows or unscoped rows in a fixed legacy session store after default-marker retirement. Written automatically during upgrade when the former owner was not main or the sole agent.",
   "talk.agentId":
     "Agent that owns Talk sessions created without an explicit agent-scoped session key.",
 };
diff --git a/src/config/sessions/legacy-main-session-migration.test.ts b/src/config/sessions/legacy-main-session-migration.test.ts
index 4898ed5af1f2..1c94064bc22b 100644
--- a/src/config/sessions/legacy-main-session-migration.test.ts
+++ b/src/config/sessions/legacy-main-session-migration.test.ts
@@ -547,7 +547,7 @@ describe("legacy main session migration", () => {
     });
   });
 
-  it("uses an explicit fixed-store owner only when the multi-agent roster is unambiguous", async () => {
+  it("uses an explicit migration owner when the multi-agent roster is unambiguous", async () => {
     const resolved = createFixture({
       agents: {
         ownership: "explicit",
@@ -577,7 +577,7 @@ describe("legacy main session migration", () => {
       env: unresolved.env,
       mode: "detect",
     });
-    const perAgentNotArmed = await migrateLegacyMainSessionKeys({
+    const perAgentArmed = await migrateLegacyMainSessionKeys({
       cfg: perAgentPinned.cfg,
       env: perAgentPinned.env,
       mode: "detect",
@@ -588,13 +588,40 @@ describe("legacy main session migration", () => {
       armed: false,
       outcomes: [{ kind: "not-armed", detail: "owner-unresolved" }],
     });
-    expect(perAgentNotArmed).toMatchObject({
-      armed: false,
-      outcomes: [{ kind: "not-armed", detail: "owner-unresolved" }],
-    });
+    expect(perAgentArmed).toMatchObject({ armed: true, ownerAgentId: "ops" });
     expect(notArmed.warnings[0]).toContain("agents.defaults.sessionStore.agentId");
   });
 
+  it("uses an explicit migration owner for retired main rows in per-agent stores", async () => {
+    const fixture = createFixture({
+      agents: {
+        ownership: "explicit",
+        defaults: { sessionStore: { agentId: "ops" } },
+        entries: { ops: {}, research: {} },
+      },
+    });
+    const mainPath = databasePath(fixture.stateDir, "main");
+    seedClaim({ databaseAgentId: "main", databasePath: mainPath, key: "agent:main:chat" });
+
+    const result = await migrateLegacyMainSessionKeys({
+      cfg: fixture.cfg,
+      env: fixture.env,
+      mode: "automatic",
+    });
+
+    expect(result).toMatchObject({ armed: true, complete: true, ownerAgentId: "ops" });
+    expect(
+      readClaim({ databaseAgentId: "main", databasePath: mainPath, key: "agent:main:chat" }),
+    ).toBeUndefined();
+    expect(
+      readClaim({
+        databaseAgentId: "ops",
+        databasePath: databasePath(fixture.stateDir, "ops"),
+        key: "agent:ops:chat",
+      }),
+    ).toBeDefined();
+  });
+
   it("keeps automatic detection non-throwing for unreadable stores and treats ENOENT as absence", async () => {
     const absent = createFixture();
     const unreadablePath = path.join(tempDirs.make("automatic-unreadable-"), "sessions.sqlite");
diff --git a/src/config/sessions/legacy-main-session-migration.ts b/src/config/sessions/legacy-main-session-migration.ts
index d7eeb7b61642..9cb1e94642e6 100644
--- a/src/config/sessions/legacy-main-session-migration.ts
+++ b/src/config/sessions/legacy-main-session-migration.ts
@@ -38,7 +38,6 @@ import type {
 import { resolveSessionStorePathCore } from "./paths.js";
 import { getSessionKysely } from "./session-accessor.sqlite-scope.js";
 import { resolveSqliteTargetFromSessionStorePath } from "./session-sqlite-target.js";
-import { isPerAgentSessionStoreConfig } from "./session-store-config.js";
 import {
   resolveAllAgentSessionStoreCandidateTargetsSync,
   resolveAgentSessionStoreTargetsSync,
@@ -73,9 +72,7 @@ function resolveArmingDecision(cfg: OpenClawConfig, legacyAgentId: string): Armi
   if (sole && roster.has(normalizeAgentId(sole))) {
     return { armed: true, ownerAgentId: normalizeAgentId(sole) };
   }
-  const sessionStoreOwner = !isPerAgentSessionStoreConfig(cfg.session?.store)
-    ? cfg.agents?.defaults?.sessionStore?.agentId?.trim()
-    : undefined;
+  const sessionStoreOwner = cfg.agents?.defaults?.sessionStore?.agentId?.trim();
   if (sessionStoreOwner) {
     const normalized = normalizeAgentId(sessionStoreOwner);
     if (roster.has(normalized)) {
diff --git a/src/config/types.agent-defaults.ts b/src/config/types.agent-defaults.ts
index 57787e90c1d0..81e1bd88e404 100644
--- a/src/config/types.agent-defaults.ts
+++ b/src/config/types.agent-defaults.ts
@@ -328,7 +328,7 @@ export type AgentDefaultsConfig = {
   authInheritance?: {
     agentId?: string;
   };
-  /** Upgrade-only owner for legacy fixed session stores until SQLite records ownership. */
+  /** Upgrade-only owner for retired main-agent rows and legacy fixed session stores. */
   sessionStore?: {
     agentId?: string;
   };