diff --git a/extensions/codex/doctor-contract-api.test.ts b/extensions/codex/doctor-contract-api.test.ts
index 7e33d250957f..4bfea48cf5a1 100644
--- a/extensions/codex/doctor-contract-api.test.ts
+++ b/extensions/codex/doctor-contract-api.test.ts
@@ -353,6 +353,156 @@ describe("codex doctor contract", () => {
     await fs.rm(fixture.stateDir, { recursive: true, force: true });
   });
 
+  it("normalizes a partial raw conversation import before copying the session row", async () => {
+    const threadId = "thread-partial-import";
+    const sessionId = "partial-import";
+    const sessionKey = "agent:main:partial-import";
+    const emptyConversation: StoredCodexAppServerBinding = {
+      version: 1,
+      state: "active",
+      binding: {
+        threadId,
+        cwd: "",
+        dynamicToolsFingerprint: "",
+      },
+    };
+    const rawFingerprint = "x".repeat(
+      65_535 - Buffer.byteLength(JSON.stringify(emptyConversation)),
+    );
+    const rawConversation: StoredCodexAppServerBinding = {
+      ...emptyConversation,
+      binding: {
+        ...emptyConversation.binding,
+        dynamicToolsFingerprint: rawFingerprint,
+      },
+    };
+    const rawSession = { ...rawConversation, sessionId };
+    expect(Buffer.byteLength(JSON.stringify(rawConversation))).toBe(65_535);
+    expect(Buffer.byteLength(JSON.stringify(rawSession))).toBeGreaterThan(65_536);
+
+    const fixture = await createBindingMigrationFixture({
+      name: sessionId,
+      sessionIndex: {
+        [sessionKey]: {
+          sessionId,
+          sessionFile: `${sessionId}.jsonl`,
+        },
+      },
+      threadId,
+      binding: { dynamicToolsFingerprint: rawFingerprint },
+    });
+    const conversationKey = bindingStoreKey({
+      kind: "conversation",
+      bindingId: legacyCodexConversationBindingId(fixture.transcriptPath),
+    });
+    const sessionBindingKey = bindingStoreKey({
+      kind: "session",
+      agentId: "main",
+      sessionId,
+      sessionKey,
+    });
+    const store = openBindingStore(fixture.env);
+    await store.register(conversationKey, rawConversation);
+
+    await expect(fixture.migration.migrateLegacyState(fixture.params)).resolves.toEqual({
+      changes: [
+        "Migrated 1 Codex app-server binding sidecar(s) to plugin state and archived the legacy sources",
+      ],
+      warnings: [],
+    });
+
+    const expectedFingerprint = hashCodexAppServerBindingFingerprint(rawFingerprint);
+    await expect(store.lookup(conversationKey)).resolves.toMatchObject({
+      state: "active",
+      binding: { dynamicToolsFingerprint: expectedFingerprint },
+    });
+    await expect(store.lookup(sessionBindingKey)).resolves.toMatchObject({
+      state: "active",
+      sessionId,
+      binding: { dynamicToolsFingerprint: expectedFingerprint },
+    });
+    await expect(fs.access(fixture.sidecarPath)).rejects.toThrow();
+    await expect(fs.access(`${fixture.sidecarPath}.migrated`)).resolves.toBeUndefined();
+    await expect(fixture.migration.migrateLegacyState(fixture.params)).resolves.toEqual({
+      changes: [],
+      warnings: [],
+    });
+
+    await fs.rm(fixture.stateDir, { recursive: true, force: true });
+  });
+
+  it("normalizes retained raw conversation and session rows before comparison", async () => {
+    const threadId = "thread-retained-import";
+    const sessionId = "retained-import";
+    const sessionKey = "agent:main:retained-import";
+    const rawFingerprint = "x".repeat(60_000);
+    const rawConversation: StoredCodexAppServerBinding = {
+      version: 1,
+      state: "active",
+      binding: {
+        threadId,
+        cwd: "",
+        dynamicToolsFingerprint: rawFingerprint,
+      },
+    };
+    const rawSession: StoredCodexAppServerBinding = {
+      ...rawConversation,
+      sessionId,
+    };
+    expect(Buffer.byteLength(JSON.stringify(rawSession))).toBeLessThan(65_536);
+
+    const fixture = await createBindingMigrationFixture({
+      name: sessionId,
+      sessionIndex: {
+        [sessionKey]: {
+          sessionId,
+          sessionFile: `${sessionId}.jsonl`,
+        },
+      },
+      threadId,
+      binding: { dynamicToolsFingerprint: rawFingerprint },
+    });
+    const conversationKey = bindingStoreKey({
+      kind: "conversation",
+      bindingId: legacyCodexConversationBindingId(fixture.transcriptPath),
+    });
+    const sessionBindingKey = bindingStoreKey({
+      kind: "session",
+      agentId: "main",
+      sessionId,
+      sessionKey,
+    });
+    const store = openBindingStore(fixture.env);
+    await store.register(conversationKey, rawConversation);
+    await store.register(sessionBindingKey, rawSession);
+
+    await expect(fixture.migration.migrateLegacyState(fixture.params)).resolves.toEqual({
+      changes: [
+        "Migrated 1 Codex app-server binding sidecar(s) to plugin state and archived the legacy sources",
+      ],
+      warnings: [],
+    });
+
+    const expectedFingerprint = hashCodexAppServerBindingFingerprint(rawFingerprint);
+    await expect(store.lookup(conversationKey)).resolves.toMatchObject({
+      state: "active",
+      binding: { dynamicToolsFingerprint: expectedFingerprint },
+    });
+    await expect(store.lookup(sessionBindingKey)).resolves.toMatchObject({
+      state: "active",
+      sessionId,
+      binding: { dynamicToolsFingerprint: expectedFingerprint },
+    });
+    await expect(fs.access(fixture.sidecarPath)).rejects.toThrow();
+    await expect(fs.access(`${fixture.sidecarPath}.migrated`)).resolves.toBeUndefined();
+    await expect(fixture.migration.migrateLegacyState(fixture.params)).resolves.toEqual({
+      changes: [],
+      warnings: [],
+    });
+
+    await fs.rm(fixture.stateDir, { recursive: true, force: true });
+  });
+
   it("matches an owner through the contained fallback for a stale session file locator", async () => {
     const sessionKey = "agent:main:stale-locator";
     const fixture = await createBindingMigrationFixture({
diff --git a/extensions/codex/src/app-server/session-binding.ts b/extensions/codex/src/app-server/session-binding.ts
index 86b7a47c1976..2cb8b1a95618 100644
--- a/extensions/codex/src/app-server/session-binding.ts
+++ b/extensions/codex/src/app-server/session-binding.ts
@@ -418,6 +418,21 @@ function normalizeLegacyBindingFingerprints(
   return normalized;
 }
 
+export function normalizeStoredCodexAppServerBindingFingerprints(
+  value: unknown,
+): StoredCodexAppServerBinding | undefined {
+  const stored = readStoredCodexAppServerBinding(value);
+  if (!stored || stored.state !== "active") {
+    return stored;
+  }
+  const binding = normalizeLegacyBindingFingerprints(
+    stored.binding as unknown as Record<string, unknown>,
+  );
+  return binding === stored.binding
+    ? stored
+    : readStoredCodexAppServerBinding({ ...stored, binding });
+}
+
 /** Encodes a migrated sidecar binding as one canonical plugin-state row. */
 export function createStoredCodexAppServerBinding(
   value: unknown,
diff --git a/extensions/codex/src/migration/session-binding-sidecars.ts b/extensions/codex/src/migration/session-binding-sidecars.ts
index 836014241dec..32087fec712c 100644
--- a/extensions/codex/src/migration/session-binding-sidecars.ts
+++ b/extensions/codex/src/migration/session-binding-sidecars.ts
@@ -415,7 +415,12 @@ async function migrateSource(
       ]);
       const raw = JSON.parse(contents) as Record<string, unknown>;
       const [
-        { bindingStoreKey, createStoredCodexAppServerBinding, readStoredCodexAppServerBinding },
+        {
+          bindingStoreKey,
+          createStoredCodexAppServerBinding,
+          normalizeStoredCodexAppServerBindingFingerprints,
+          readStoredCodexAppServerBinding,
+        },
         { legacyCodexConversationBindingId },
       ] = await Promise.all([
         import("../app-server/session-binding.js"),
@@ -458,17 +463,53 @@ async function migrateSource(
           bindingId: legacyCodexConversationBindingId(sessionFile),
         }),
       );
+      const normalizeStoredRow = async (
+        key: string,
+        current: MigratedBindingRow,
+      ): Promise<{ value?: MigratedBindingRow; warning?: string }> => {
+        const parsed = readStoredCodexAppServerBinding(current);
+        if (!parsed) {
+          return { warning: `canonical plugin state is invalid at ${key}` };
+        }
+        const normalized = normalizeStoredCodexAppServerBindingFingerprints(parsed);
+        if (!normalized) {
+          return { warning: `canonical plugin state is invalid at ${key}` };
+        }
+        if (isDeepStrictEqual(parsed, normalized)) {
+          return { value: parsed };
+        }
+        if (parsed.lease && parsed.lease.expiresAt > Date.now()) {
+          return { warning: `canonical plugin state is leased at ${key}` };
+        }
+        const update = store.update;
+        if (!update) {
+          return { warning: `canonical plugin state could not be normalized at ${key}` };
+        }
+        await update(key, (candidate) => {
+          const candidateParsed = readStoredCodexAppServerBinding(candidate);
+          if (!candidateParsed || !isDeepStrictEqual(candidateParsed, parsed)) {
+            return undefined;
+          }
+          return normalized;
+        });
+        const persisted = readStoredCodexAppServerBinding(await store.lookup(key));
+        if (!persisted || !isDeepStrictEqual(persisted, normalized)) {
+          return { warning: `canonical plugin state changed at ${key}` };
+        }
+        importedKeys++;
+        return { value: normalized };
+      };
       let currentConversation: MigratedBindingRow | undefined;
       for (const key of conversationKeys) {
         const current = await store.lookup(key);
         if (current === undefined) {
           continue;
         }
-        const parsed = readStoredCodexAppServerBinding(current);
-        if (!parsed) {
-          return retain(`canonical plugin state is invalid at ${key}`);
+        const result = await normalizeStoredRow(key, current);
+        if (result.warning || !result.value) {
+          return retain(result.warning ?? `canonical plugin state is invalid at ${key}`);
         }
-        currentConversation ??= parsed;
+        currentConversation ??= result.value;
       }
       const stored = currentConversation ?? baseStored;
       const sessionKey = owner
@@ -500,7 +541,14 @@ async function migrateSource(
       };
       for (const entry of entries) {
         const current = await store.lookup(entry.key);
-        if (current !== undefined && !hasExpected(current, entry.value)) {
+        if (current === undefined) {
+          continue;
+        }
+        const result = await normalizeStoredRow(entry.key, current);
+        if (result.warning || !result.value) {
+          return retain(result.warning ?? `canonical plugin state is invalid at ${entry.key}`);
+        }
+        if (!hasExpected(result.value, entry.value)) {
           return retain(`canonical plugin state changed at ${entry.key}`);
         }
       }