diff --git a/internal/appsetup/appsetup_test.go b/internal/appsetup/appsetup_test.go
index 219d548a47..49a3ce961d 100644
--- a/internal/appsetup/appsetup_test.go
+++ b/internal/appsetup/appsetup_test.go
@@ -365,6 +365,36 @@ func TestSetup_ExistingApp_OrgOwned_NoSecret_EntersRecovery(t *testing.T) {
 	assert.Contains(t, err.Error(), "private key secret is missing")
 }
 
+func TestSetup_ExistingApp_NoSecretExistsFunc_ReuseSilently(t *testing.T) {
+	// When no secretExists callback is configured (e.g. github setup in
+	// OIDC mint mode with no local GCP project), existing apps should be
+	// reused silently without prompting for a PEM file.
+	client := &forge.FakeClient{
+		Installations: []forge.Installation{
+			{ID: 100, AppID: 10, AppSlug: "fullsend-triage"},
+		},
+		AppClientIDs: map[string]string{
+			"fullsend-triage": "Iv1.triage123",
+		},
+	}
+	prompter := &fakePrompter{}
+	printer := ui.New(&discardWriter{})
+
+	s := NewSetup(client, prompter, newFakeBrowser(), printer).
+		WithAppSet("fullsend")
+	// Deliberately NOT calling WithSecretExists — simulates the OIDC
+	// mint-URL-only path where the remote mint manages PEMs.
+
+	creds, err := s.Run(context.Background(), "myorg", "triage")
+	require.NoError(t, err)
+	assert.Equal(t, 10, creds.AppID)
+	assert.Equal(t, "fullsend-triage", creds.Slug)
+	assert.Equal(t, "Iv1.triage123", creds.ClientID)
+	assert.Empty(t, creds.PEM, "PEM should be empty to signal reuse")
+	assert.False(t, prompter.confirmCalled, "should not prompt for PEM recovery")
+	assert.False(t, prompter.readLineCalled, "should not ask for PEM file path")
+}
+
 func TestIsOrgOwned(t *testing.T) {
 	s := &Setup{}
 
diff --git a/internal/cli/admin.go b/internal/cli/admin.go
index 0e23ad809d..3244ea40b0 100644
--- a/internal/cli/admin.go
+++ b/internal/cli/admin.go
@@ -532,7 +532,7 @@ Inference authentication:
 				if err := ensureConfigRepoExists(ctx, client, printer, org); err != nil {
 					return err
 				}
-				creds, err := runAppSetup(ctx, client, printer, org, roles, mintProject, publicApps, sharedSlugs, appSet, perOrgStoredIDs)
+				creds, err := runAppSetup(ctx, client, printer, org, roles, mintProject, mintURL, publicApps, sharedSlugs, appSet, perOrgStoredIDs)
 				if err != nil {
 					return err
 				}
@@ -893,7 +893,7 @@ func runPerRepoInstall(ctx context.Context, c perRepoInstallConfig) error {
 			}
 		}
 
-		creds, credErr := runAppSetup(ctx, client, printer, owner, roles, mintProject, publicApps, sharedSlugs, c.AppSet, existingIDs)
+		creds, credErr := runAppSetup(ctx, client, printer, owner, roles, mintProject, mintURL, publicApps, sharedSlugs, c.AppSet, existingIDs)
 		if credErr != nil {
 			return credErr
 		}
@@ -1310,8 +1310,11 @@ func detectSharedApps(ctx context.Context, client forge.Client, printer *ui.Prin
 
 // runAppSetup creates or reuses GitHub Apps for each role. When mintProject is
 // non-empty, PEMs are also stored in GCP Secret Manager during app creation so
-// they survive partial provisioning failures.
-func runAppSetup(ctx context.Context, client forge.Client, printer *ui.Printer, org string, roles []string, mintProject string, publicApps bool, sharedSlugs map[string]string, appSet string, storedAppIDs map[string]string) ([]layers.AgentCredentials, error) {
+// they survive partial provisioning failures. When mintURL is non-empty but
+// mintProject is empty (e.g. the "github setup" flow), PEMs are managed by a
+// remote mint — the secret-existence check is skipped and existing apps are
+// reused silently.
+func runAppSetup(ctx context.Context, client forge.Client, printer *ui.Printer, org string, roles []string, mintProject string, mintURL string, publicApps bool, sharedSlugs map[string]string, appSet string, storedAppIDs map[string]string) ([]layers.AgentCredentials, error) {
 	printer.Header("Setting up GitHub Apps")
 	printer.Blank()
 
@@ -1343,26 +1346,31 @@ func runAppSetup(ctx context.Context, client forge.Client, printer *ui.Printer,
 		}, gcf.NewLiveGCFClient(mintProject))
 	}
 
-	// In OIDC mint mode, PEMs live in Secret Manager — check there.
+	// In OIDC mint mode with direct GCP access, PEMs live in Secret
+	// Manager — check there.  When only a mint URL is available (no local
+	// GCP project), the remote mint manages PEMs and we cannot verify
+	// their existence — skip the check so handleExistingApp assumes reuse.
 	// Otherwise, check GitHub repo secrets.
 	if pemProvisioner != nil {
 		setup = setup.WithSecretExists(func(role string) (bool, error) {
 			return pemProvisioner.SecretExists(ctx, role)
 		})
-	} else {
+	} else if mintURL == "" {
 		setup = setup.WithSecretExists(func(role string) (bool, error) {
 			secretName := fmt.Sprintf("FULLSEND_%s_APP_PRIVATE_KEY", strings.ToUpper(role))
 			return client.RepoSecretExists(ctx, org, forge.ConfigRepoName, secretName)
 		})
 	}
 
-	// In OIDC mint mode, store PEMs only in Secret Manager.
+	// In OIDC mint mode with direct GCP access, store PEMs only in Secret
+	// Manager.  When only a mint URL is available, PEM storage is handled
+	// by the remote mint — skip local storage.
 	// Otherwise, store in GitHub repo secrets.
 	if pemProvisioner != nil {
 		setup = setup.WithStoreSecret(func(sctx context.Context, role, pem string) error {
 			return pemProvisioner.StoreAgentPEM(sctx, role, []byte(pem))
 		})
-	} else {
+	} else if mintURL == "" {
 		setup = setup.WithStoreSecret(func(sctx context.Context, role, pem string) error {
 			secretName := fmt.Sprintf("FULLSEND_%s_APP_PRIVATE_KEY", strings.ToUpper(role))
 			return client.CreateRepoSecret(sctx, org, forge.ConfigRepoName, secretName, pem)
diff --git a/internal/cli/github.go b/internal/cli/github.go
index ed695b7213..6e5d8b9393 100644
--- a/internal/cli/github.go
+++ b/internal/cli/github.go
@@ -499,7 +499,7 @@ func runGitHubSetupPerOrg(ctx context.Context, client forge.Client, printer *ui.
 			return err
 		}
 
-		creds, credErr := runAppSetup(ctx, client, printer, org, roles, "", cfg.publicApps, nil, cfg.appSet, nil)
+		creds, credErr := runAppSetup(ctx, client, printer, org, roles, "", cfg.mintURL, cfg.publicApps, nil, cfg.appSet, nil)
 		if credErr != nil {
 			return credErr
 		}