diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 3683014b3..22a3b4623 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -97,7 +97,7 @@ below describes the current layout as the migration proceeds.
 - `internal/testutil/console/` contains shared synthetic Windows console records
   and observer fixtures used only by native feature tests.
 - `internal/app/` owns invocation, request-environment scope, completion setup,
-  output policy, and exit-status selection. Command assembly still uses the
+  output policy, help assembly, and exit-status selection. Command assembly still uses the
   existing generated tree during the layout migration.
 - `api_reference/openapi.transformed.yml` contains the OpenAPI specification
   used by the mock server.
diff --git a/cmd/openai/error_coverage_test.go b/cmd/openai/error_coverage_test.go
index b8acc92cd..6fc4edc96 100644
--- a/cmd/openai/error_coverage_test.go
+++ b/cmd/openai/error_coverage_test.go
@@ -21,6 +21,7 @@ import (
 	"time"
 
 	"github.com/openai/openai-cli/generated/commands"
+	"github.com/openai/openai-cli/internal/app"
 	"github.com/openai/openai-cli/internal/requestflag"
 	"github.com/openai/openai-cli/pkg/custom"
 	"github.com/urfave/cli/v3"
@@ -310,7 +311,7 @@ func TestMainErrorCoverageManifestProcess(t *testing.T) {
 	}
 	root := commands.Command
 	root.Flags = append(root.Flags, custom.NewRequestHeaderFlag())
-	if _, _, err := custom.ConfigureHelp(root, []string{"openai", "--help"}); err != nil {
+	if _, _, err := app.ConfigureHelp(root, []string{"openai", "--help"}); err != nil {
 		t.Fatal(err)
 	}
 	custom.ConfigureCommandErrors(root)
diff --git a/docs/architecture/repository-layout.md b/docs/architecture/repository-layout.md
index ffbba0233..62acf7ec8 100644
--- a/docs/architecture/repository-layout.md
+++ b/docs/architecture/repository-layout.md
@@ -351,3 +351,7 @@ entrypoint contracts, check platform compilation, and verify that generated file
 and dependency manifests are untouched. For generator changes, additionally
 verify regenerated snapshots and a repeat generation with no unexplained drift.
 Keep release, signing, CODEOWNER, merge-queue, and trusted-main controls intact.
+
+Help assembly and its contracts live in `internal/app/`: root flag descriptions,
+feature help content, flag groups, and admin setup guidance are configured there
+in the existing order. Rendering remains in `internal/clihelp/`.
diff --git a/pkg/custom/admin_setup_test.go b/internal/app/admin_setup_test.go
similarity index 99%
rename from pkg/custom/admin_setup_test.go
rename to internal/app/admin_setup_test.go
index 1ec2afb4e..6434da788 100644
--- a/pkg/custom/admin_setup_test.go
+++ b/internal/app/admin_setup_test.go
@@ -1,4 +1,4 @@
-package custom
+package app
 
 import (
 	"bytes"
diff --git a/pkg/custom/help.go b/internal/app/help.go
similarity index 99%
rename from pkg/custom/help.go
rename to internal/app/help.go
index 022ba7f4e..8fc3451f3 100644
--- a/pkg/custom/help.go
+++ b/internal/app/help.go
@@ -1,4 +1,4 @@
-package custom
+package app
 
 import (
 	"strings"
diff --git a/pkg/custom/help_test.go b/internal/app/help_test.go
similarity index 97%
rename from pkg/custom/help_test.go
rename to internal/app/help_test.go
index bfffc8599..9ac8f6d09 100644
--- a/pkg/custom/help_test.go
+++ b/internal/app/help_test.go
@@ -1,4 +1,4 @@
-package custom
+package app
 
 import (
 	"bytes"
@@ -11,6 +11,7 @@ import (
 	imagecommands "github.com/openai/openai-cli/internal/commands/images"
 	requestconfig "github.com/openai/openai-cli/internal/request"
 	"github.com/openai/openai-cli/internal/requestflag"
+	"github.com/openai/openai-cli/pkg/custom"
 	"github.com/urfave/cli/v3"
 )
 
@@ -156,9 +157,9 @@ func TestConfigureHelpPreservesImageGuidance(t *testing.T) {
 		{Name: "unrelated", Description: "Keep this description", CustomHelpTemplate: "Keep this template"},
 	}}
 	root := &cli.Command{Name: "openai", Commands: []*cli.Command{images}}
-	imagecommands.ConfigureSaving(root, ImageSavingOptions())
-	imagecommands.RegisterPreview(root, ImagePreviewOptions())
-	imagecommands.RegisterModels(root, ImageModelOptions())
+	imagecommands.ConfigureSaving(root, custom.ImageSavingOptions())
+	imagecommands.RegisterPreview(root, custom.ImagePreviewOptions())
+	imagecommands.RegisterModels(root, custom.ImageModelOptions())
 	wantGuidance := map[string][]string{
 		"generate":         {"interactive terminal", "picker reopens", "Ctrl+C exits", "~/Downloads/gpt-images/", "--format json", "without --name or --output-dir", "depend on the model"},
 		"edit":             {"Replace photo.png", "Keeps your original", "~/Downloads/gpt-images/", "existing folder", "--format json", "depend on the model"},
diff --git a/internal/app/run.go b/internal/app/run.go
index bf8e7f85d..cbfb19725 100644
--- a/internal/app/run.go
+++ b/internal/app/run.go
@@ -47,7 +47,7 @@ func Run(ctx context.Context, argv []string) int {
 		prepareForAutocomplete(app)
 	}
 
-	args, _, err := custom.ConfigureHelp(app, argv)
+	args, _, err := ConfigureHelp(app, argv)
 	custom.ConfigureCommandErrors(app)
 
 	if err == nil {
diff --git a/internal/clihelp/request_inputs_test.go b/internal/clihelp/request_inputs_test.go
index a2974256e..90fdc9ac2 100644
--- a/internal/clihelp/request_inputs_test.go
+++ b/internal/clihelp/request_inputs_test.go
@@ -7,10 +7,10 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/openai/openai-cli/internal/app"
 	"github.com/openai/openai-cli/internal/clihelp"
 	localcommands "github.com/openai/openai-cli/internal/commands"
 	"github.com/openai/openai-cli/internal/requestflag"
-	"github.com/openai/openai-cli/pkg/custom"
 	"github.com/urfave/cli/v3"
 )
 
@@ -55,7 +55,7 @@ func TestDescribeRequestInputsSurvivesResourceCloning(t *testing.T) {
 		clihelp.DescribeRequestInputs(root)
 		localcommands.ConfigureSubgroups(root)
 		args := append(append([]string{"openai"}, path...), "--help")
-		args, _, err := custom.ConfigureHelp(root, args)
+		args, _, err := app.ConfigureHelp(root, args)
 		if err != nil {
 			t.Fatal(err)
 		}