diff --git a/doc/connections/AI-CONNECTIONS.md b/doc/connections/AI-CONNECTIONS.md
index 4e2c0494c33..96289490ede 100644
--- a/doc/connections/AI-CONNECTIONS.md
+++ b/doc/connections/AI-CONNECTIONS.md
@@ -834,3 +834,17 @@ updates, account changes, duplicate identity resolution, ownership, monetary
 receipt replay, unknown prices, and failed provider observations. Provider payloads
 are fixtures; live provider access still depends on the deployment's credentials
 and scopes.
+
+### Login completion ownership
+
+The internal connection save service takes an internal auth-session row ID for
+every login flow. The setup-token owner resolves its public session ID within
+the company, user, and adapter scope before calling save. Local and device
+logins already use internal IDs. Provider names do not select the ID column.
+
+A login flow can supply a completion callback that runs inside the connection
+save transaction, after the session binding is written. Setup-token completion
+uses its existing conditional transition to `stored`; a rejected transition
+rolls back the credentials and connection binding. Already-bound sessions return
+the existing connection without repeating the callback. Local and device login
+services continue to own their final states.
diff --git a/server/src/__tests__/ai-connections.test.ts b/server/src/__tests__/ai-connections.test.ts
index 183052c5105..49b9cd7d81d 100644
--- a/server/src/__tests__/ai-connections.test.ts
+++ b/server/src/__tests__/ai-connections.test.ts
@@ -1,3 +1,4 @@
+import { completeSetupTokenAiConnection } from "../services/setup-token-ai-connection.js";
 import { connectionIntentService } from "../services/connection-intents.js";
 import { connectionIntentDeliveryService } from "../services/connection-intent-delivery.js";
 import { issueRecoveryActionService } from "../services/issue-recovery-actions.js";
@@ -844,7 +845,7 @@ describe("managed AI connections", () => {
       lock = vi.spyOn(codexAdapter, "withAccountHomeSecretMutationLock")
         .mockRejectedValueOnce(Object.assign(new Error("lock timeout"), { code: WORKSPACE_RESTORE_LOCK_TIMEOUT_CODE }))
         .mockRejectedValueOnce(Object.assign(new Error("lock timeout"), { code: WORKSPACE_RESTORE_LOCK_TIMEOUT_CODE }));
-      saving = service.save(companyId, loginOwner, { ...intent, agentIds: [] }, credential, sessionId);
+      saving = service.save(companyId, loginOwner, { ...intent, agentIds: [] }, credential, { id: sessionId });
       void saving.catch(() => {});
       await vi.waitFor(() => expect(lock).toHaveBeenCalledTimes(3));
       expect((await db.select().from(adapterAuthSessions).where(eq(adapterAuthSessions.id, sessionId)))[0].connectionId).toBeNull();
@@ -852,7 +853,7 @@ describe("managed AI connections", () => {
       const [, saved] = await Promise.all([refreshing, saving]);
       const [row] = (await service.quotaAccounts(companyId, loginOwner)).filter(row => row.connection.id === saved.connectionId);
       expect(await service.credential(row)).toBe(credential);
-      expect(await service.save(companyId, loginOwner, { ...intent, agentIds: [] }, credential, sessionId)).toEqual(saved);
+      expect(await service.save(companyId, loginOwner, { ...intent, agentIds: [] }, credential, { id: sessionId })).toEqual(saved);
       if (kind === "new") expect(JSON.parse(await service.credential(quotaRow))).toMatchObject({ tokens: { access_token: "quota-fresh", refresh_token: "quota-replacement" } });
     } finally {
       release.resolve(); await Promise.allSettled([refreshing, saving]); lock?.mockRestore(); request.mockRestore();
@@ -1667,11 +1668,57 @@ console.log(JSON.stringify({ type: "result", subtype: "success", result: "hello"
     const intent = { provider: "anthropic", method: "subscription", ownership: "personal", name: "Claude subscription", agentIds: [], allAgents: true } as const;
     const sessionId = randomUUID();
     await db.insert(adapterAuthSessions).values({ companyId, environmentId: environment.id, adapterType: "claude_local", startedByUserId: "alice", publicSessionId: sessionId, status: "submitting", aiConnection: { ...intent, agentIds: [] }, expiresAt: new Date(Date.now() + 60000) });
-    const first = await service.save(companyId, "alice", { ...intent, agentIds: [] }, "fixture-subscription", sessionId);
-    expect(await service.save(companyId, "alice", { ...intent, agentIds: [] }, "fixture-subscription", sessionId)).toEqual(first);
+    const first = await completeSetupTokenAiConnection(db, { scope: { companyId, ownerUserId: "alice", environmentId: environment.id, adapterType: "claude_local", aiConnection: { ...intent, agentIds: [] } }, token: "fixture-subscription", sessionId });
+    expect(await completeSetupTokenAiConnection(db, { scope: { companyId, ownerUserId: "alice", environmentId: environment.id, adapterType: "claude_local", aiConnection: { ...intent, agentIds: [] } }, token: "fixture-subscription", sessionId })).toEqual(first);
+    expect((await db.select().from(adapterAuthSessions).where(eq(adapterAuthSessions.publicSessionId, sessionId)))[0]).toMatchObject({ status: "stored", connectionId: first.connectionId, connectionGrantId: first.grantId });
     const cancelled = randomUUID();
     await db.insert(adapterAuthSessions).values({ companyId, environmentId: environment.id, adapterType: "claude_local", startedByUserId: "alice", publicSessionId: cancelled, status: "cancelled", expiresAt: new Date(Date.now() + 60000) });
-    await expect(service.save(companyId, "alice", { ...intent, agentIds: [] }, "fixture-never-save", cancelled)).rejects.toThrow("no longer active");
+    await expect(completeSetupTokenAiConnection(db, { scope: { companyId, ownerUserId: "alice", environmentId: environment.id, adapterType: "claude_local", aiConnection: { ...intent, agentIds: [] } }, token: "fixture-never-save", sessionId: cancelled })).rejects.toThrow("no longer active");
+  });
+  it.each(["anthropic", "openai"] as const)("binds %s by internal session ID without choosing its completion state", async provider => {
+    const owner = `session-owner-${provider}`;
+    await db.insert(companyMemberships).values({ companyId, principalId: owner, principalType: "user", status: "active", membershipRole: "member" });
+    const [environment] = await db.insert(environments).values({ name: `Session identity ${provider}`, driver: "sandbox" }).returning();
+    const intent = { provider, method: "subscription", ownership: "personal", name: `Session identity ${provider}`, allAgents: false, agentIds: [] } as const;
+    const [session] = await db.insert(adapterAuthSessions).values({ companyId, environmentId: environment.id,
+      adapterType: provider === "anthropic" ? "claude_local" : "codex_local", startedByUserId: owner,
+      publicSessionId: randomUUID(), status: "promoting", aiConnection: { ...intent, agentIds: [] },
+      expiresAt: new Date(Date.now() + 60_000),
+    }).returning();
+    const complete = vi.fn(async () => {});
+    try {
+      await expect(service.save(companyId, owner, { ...intent, agentIds: [] }, "fixture", { id: session.publicSessionId, complete })).rejects.toThrow("ownership mismatch");
+      await expect(service.save(companyId, "bob", { ...intent, agentIds: [] }, "fixture", { id: session.id, complete })).rejects.toThrow("ownership mismatch");
+      await expect(service.save(companyId, owner, { ...intent, agentIds: [], ownership: "shared" }, "fixture", { id: session.id, complete })).rejects.toThrow("target mismatch");
+      expect(complete).not.toHaveBeenCalled();
+      const saved = await service.save(companyId, owner, { ...intent, agentIds: [] }, "fixture", { id: session.id, complete });
+      expect((await db.select().from(adapterAuthSessions).where(eq(adapterAuthSessions.id, session.id)))[0]).toMatchObject({
+        connectionId: saved.connectionId, connectionGrantId: saved.grantId, status: "promoting",
+      });
+      expect(await service.save(companyId, owner, { ...intent, agentIds: [] }, "replacement", { id: session.id, complete })).toEqual(saved);
+      expect(complete).toHaveBeenCalledTimes(1);
+    } finally { await db.delete(adapterAuthSessions).where(eq(adapterAuthSessions.id, session.id)); }
+  });
+  it("rolls back credential and connection writes if setup-token completion loses its claim", async () => {
+    const owner = "lost-setup-token-claim";
+    await db.insert(companyMemberships).values({ companyId, principalId: owner, principalType: "user", status: "active", membershipRole: "member" });
+    const [environment] = await db.insert(environments).values({ name: "Lost setup claim", driver: "sandbox" }).returning();
+    const intent = { provider: "anthropic", method: "subscription", ownership: "personal", name: "Lost setup claim", allAgents: false, agentIds: [] } as const;
+    const [session] = await db.insert(adapterAuthSessions).values({ companyId, environmentId: environment.id,
+      adapterType: "claude_local", startedByUserId: owner, publicSessionId: randomUUID(), status: "submitting",
+      aiConnection: { ...intent, agentIds: [] }, expiresAt: new Date(Date.now() + 60_000), boundAt: new Date(),
+    }).returning();
+    try {
+      await expect(completeSetupTokenAiConnection(db, { scope: { companyId, ownerUserId: owner,
+        environmentId: environment.id, adapterType: "claude_local", aiConnection: { ...intent, agentIds: [] } },
+        sessionId: session.publicSessionId, token: "must-rollback",
+      })).rejects.toThrow();
+      expect((await db.select().from(adapterAuthSessions).where(eq(adapterAuthSessions.id, session.id)))[0]).toMatchObject({
+        connectionId: null, connectionGrantId: null, status: "submitting",
+      });
+      expect(await db.select().from(toolConnections).where(and(eq(toolConnections.companyId, companyId), eq(toolConnections.name, intent.name)))).toEqual([]);
+      expect(await db.select().from(companySecrets).where(eq(companySecrets.ownerUserId, owner))).toEqual([]);
+    } finally { await db.delete(adapterAuthSessions).where(eq(adapterAuthSessions.id, session.id)); }
   });
   it("preserves connection identity and defaults through reconnect; revocation wins over older attempts", async () => {
     const current = await service.select({ ...input, userId: "bob" });
@@ -1919,7 +1966,7 @@ console.log(JSON.stringify({ type: "result", subtype: "success", result: "hello"
     const sessionId = randomUUID();
     const intent = { provider: "anthropic", method: "subscription", ownership: "personal", name: "Expired", agentIds: [], allAgents: true } as const;
     await db.insert(adapterAuthSessions).values({ companyId, environmentId: environment.id, adapterType: "claude_local", startedByUserId: "alice", publicSessionId: sessionId, status: "submitting", aiConnection: { ...intent, agentIds: [] }, expiresAt: new Date(Date.now() - 1000) });
-    await expect(service.save(companyId, "alice", { ...intent, agentIds: [] }, "fixture-never-save", sessionId)).rejects.toThrow("no longer active");
+    await expect(completeSetupTokenAiConnection(db, { scope: { companyId, ownerUserId: "alice", environmentId: environment.id, adapterType: "claude_local", aiConnection: { ...intent, agentIds: [] } }, token: "fixture-never-save", sessionId })).rejects.toThrow("no longer active");
     expect((await service.list(companyId, "alice")).some(account => account.name === "Expired")).toBe(false);
   });
   it("authorizes account creation, reconnect and defaults at the HTTP boundary before provider calls", async () => {
@@ -2040,6 +2087,7 @@ console.log(JSON.stringify({ type: "result", subtype: "success", result: "hello"
       expect(started.headers["cache-control"]).toBe("no-store");
       expect(started.body.command).toBeUndefined();
       expect((await request(app).post(`${base}/attempts`).send(intent)).body).toEqual(started.body);
+      await db.update(adapterAuthSessions).set({ publicSessionId: randomUUID() }).where(eq(adapterAuthSessions.id, started.body.sessionId));
       const input = { ...intent, localSessionId: started.body.sessionId };
       for (const endpoint of [base, `${base}/check`]) {
         expect((await request(app).post(endpoint).set("x-test-user", "bob").send(input)).status).toBe(404);
diff --git a/server/src/routes/agents.ts b/server/src/routes/agents.ts
index fefd2afed44..a89ed24a218 100644
--- a/server/src/routes/agents.ts
+++ b/server/src/routes/agents.ts
@@ -1,3 +1,4 @@
+import { completeSetupTokenAiConnection } from "../services/setup-token-ai-connection.js";
 import { cancellationRequestId } from "../services/native-runtime/native-cancellation-request.js";
 import { agentHarnessType, type AgentRunnerChoice } from "@paperclipai/shared";
 import { resolveNewAgentRunnerForCompany } from "../services/agent-runner-selection.js";
@@ -743,7 +744,7 @@ export function agentRoutes(
     store: setupTokenCleanupStore,
     completeCredential: async (input) => {
       if (!input.scope.aiConnection) return setupTokenSecretWriter(input);
-      await aiConnectionService(db).save(input.scope.companyId, input.scope.ownerUserId, input.scope.aiConnection, input.token, input.sessionId);
+      await completeSetupTokenAiConnection(db, input);
     },
     rateLimiter: setupTokenRateLimiter,
   });
@@ -880,7 +881,7 @@ export function agentRoutes(
           if (managedSession?.aiConnection) {
             await adapterLoginStore.withCompanyAdapterPromotionLock(context.companyId, context.startedByUserId, context.adapterType, async () => {
               if (!(await checkStagedCredentialReadiness(authBytes)).ready) throw new Error("Provider credential is not ready");
-              await aiConnectionService(db).save(context.companyId, context.startedByUserId, managedSession.aiConnection!, authBytes.toString("utf8"), context.sessionId);
+              await aiConnectionService(db).save(context.companyId, context.startedByUserId, managedSession.aiConnection!, authBytes.toString("utf8"), { id: context.sessionId });
             });
             return;
           }
@@ -1125,7 +1126,7 @@ export function agentRoutes(
           if (managedSession?.aiConnection) {
             await adapterLoginStore.withCompanyAdapterPromotionLock(context.companyId, context.startedByUserId, context.adapterType, async () => {
               if (!(await checkStagedGrokCredentialReadiness(authBytes)).ready) throw new Error("Provider credential is not ready");
-              await aiConnectionService(db).save(context.companyId, context.startedByUserId, managedSession.aiConnection!, authBytes.toString("utf8"), context.sessionId);
+              await aiConnectionService(db).save(context.companyId, context.startedByUserId, managedSession.aiConnection!, authBytes.toString("utf8"), { id: context.sessionId });
             });
             return;
           }
diff --git a/server/src/services/ai-connections.ts b/server/src/services/ai-connections.ts
index a12fbd744b6..0177f6352ac 100644
--- a/server/src/services/ai-connections.ts
+++ b/server/src/services/ai-connections.ts
@@ -569,7 +569,7 @@ export function aiConnectionService(db: Db) {
     userId: string,
     input: CreateAiConnection | AiConnectionLoginIntent,
     verifiedCredential: string,
-    sessionId?: string,
+    loginSession?: { id: string; complete?: (tx: Db) => Promise<void> },
     attemptStartedAt = new Date(),
   ) {
     const routing = "routing" in input ? input.routing : undefined;
@@ -610,15 +610,13 @@ export function aiConnectionService(db: Db) {
     const grantId = reconnect?.grant.id ?? randomUUID();
     const persist = () => withAccountHomeSecretMutationLock(undefined, companyId, () => db.transaction(async (tx) => {
       const secrets = secretService(tx);
-      if (sessionId) {
+      if (loginSession) {
         const [session] = await tx
           .select()
           .from(adapterAuthSessions)
           .where(
             and(
-              input.provider === "anthropic"
-                ? eq(adapterAuthSessions.publicSessionId, sessionId)
-                : eq(adapterAuthSessions.id, sessionId),
+              eq(adapterAuthSessions.id, loginSession.id),
               eq(adapterAuthSessions.companyId, companyId),
               eq(adapterAuthSessions.startedByUserId, userId),
             ),
@@ -888,22 +886,18 @@ export function aiConnectionService(db: Db) {
               })),
             );
       }
-      if (sessionId)
+      if (loginSession)
         await tx
           .update(adapterAuthSessions)
           .set({
             connectionId: id,
             connectionGrantId: grantId,
             connectionMethod: input.method,
-            ...(input.provider === "anthropic"
-              ? { status: "stored" as const }
-              : {}),
           })
           .where(
-            input.provider === "anthropic"
-              ? eq(adapterAuthSessions.publicSessionId, sessionId)
-              : eq(adapterAuthSessions.id, sessionId),
+            eq(adapterAuthSessions.id, loginSession.id),
           );
+      await loginSession?.complete?.(tx as unknown as Db);
       await logActivity(tx as unknown as Db, {
         companyId,
         actorType: "user",
diff --git a/server/src/services/local-ai-login.ts b/server/src/services/local-ai-login.ts
index 2108a916baf..3da1fa60ec7 100644
--- a/server/src/services/local-ai-login.ts
+++ b/server/src/services/local-ai-login.ts
@@ -222,7 +222,7 @@ export function localAiLoginService(db: Db) {
       // Nested transaction is a savepoint on this same connection. Holding the
       // attempt lock makes completion/cancellation/restart retries idempotent.
       const saved = await aiConnectionService(tx as unknown as Db)
-        .save(companyId, userId, intent, credential, id, session.createdAt);
+        .save(companyId, userId, intent, credential, { id }, session.createdAt);
       await tx.update(adapterAuthSessions).set({
         status: "authenticated", connectionMethod: LOCAL_LOGIN_METHOD,
         finishedAt: new Date(), updatedAt: new Date(),
diff --git a/server/src/services/setup-token-ai-connection.ts b/server/src/services/setup-token-ai-connection.ts
new file mode 100644
index 00000000000..4b3547816fa
--- /dev/null
+++ b/server/src/services/setup-token-ai-connection.ts
@@ -0,0 +1,34 @@
+import { and, eq } from "drizzle-orm";
+import { adapterAuthSessions, type Db } from "@paperclipai/db";
+import type { AgentAdapterType } from "@paperclipai/shared";
+import { forbidden } from "../errors.js";
+import { aiConnectionService } from "./ai-connections.js";
+import {
+  SETUP_TOKEN_STORAGE_FAILED,
+  SetupTokenSessionError,
+  transitionSetupTokenSessionToStored,
+  type SetupTokenSecretWriter,
+} from "./setup-token-session.js";
+
+export async function completeSetupTokenAiConnection(
+  db: Db,
+  { scope, sessionId, token }: Parameters<SetupTokenSecretWriter>[0],
+) {
+  if (!scope.aiConnection) throw new SetupTokenSessionError(500, SETUP_TOKEN_STORAGE_FAILED);
+  const [session] = await db.select({ id: adapterAuthSessions.id }).from(adapterAuthSessions).where(and(
+    eq(adapterAuthSessions.publicSessionId, sessionId),
+    eq(adapterAuthSessions.companyId, scope.companyId),
+    eq(adapterAuthSessions.startedByUserId, scope.ownerUserId),
+    eq(adapterAuthSessions.adapterType, scope.adapterType as AgentAdapterType),
+  ));
+  if (!session) throw forbidden("Login session ownership mismatch");
+  return aiConnectionService(db).save(scope.companyId, scope.ownerUserId, scope.aiConnection, token, {
+    id: session.id,
+    complete: async (tx) => {
+      const transitioned = await transitionSetupTokenSessionToStored(tx, {
+        sessionId, companyId: scope.companyId, ownerUserId: scope.ownerUserId, adapterType: scope.adapterType,
+      });
+      if (!transitioned) throw new SetupTokenSessionError(500, SETUP_TOKEN_STORAGE_FAILED);
+    },
+  });
+}