From c0d4ea0d4e0be340e63fb5ac83c0154a0557226f Mon Sep 17 00:00:00 2001
From: Eric Rakestraw <eric@rakestraw.us>
Date: Tue, 28 Jul 2026 01:20:41 +0000
Subject: [PATCH] Preserve public error categories from collaborators

---
 engine_test.go | 26 ++++++++++++++++++++++++++
 errors.go      | 25 -------------------------
 2 files changed, 26 insertions(+), 25 deletions(-)

diff --git a/engine_test.go b/engine_test.go
index 0d95ae1..f2719ec 100644
--- a/engine_test.go
+++ b/engine_test.go
@@ -915,6 +915,12 @@ func TestArtifactReaderFailuresPreserveArtifactLoadErrors(t *testing.T) {
 			}},
 			wantNested: context.Canceled,
 		},
+		{
+			name:       "public reader error",
+			ctx:        context.Background(),
+			reader:     &recordingArtifactReader{err: scriptorium.ErrInvalidRequest},
+			wantNested: scriptorium.ErrInvalidRequest,
+		},
 	}
 
 	for _, tc := range tests {
@@ -936,6 +942,26 @@ func TestArtifactReaderFailuresPreserveArtifactLoadErrors(t *testing.T) {
 	}
 }
 
+func TestRunAddsLLMGenerateToCollaboratorPublicError(t *testing.T) {
+	engine := newContractEngineWithOptions(t, frameworkSchemaDir,
+		scriptorium.WithLLMClient(&fakeLLMClient{err: scriptorium.ErrArtifactLoad}),
+	)
+
+	_, err := engine.Run(context.Background(), scriptorium.RunRequest{
+		PromptID: frameworkMarkdownSummaryPromptID,
+		Inputs: map[string]scriptorium.ArtifactRef{
+			"transcript": scriptorium.Inline("Rin opens the gate."),
+			"glossary":   scriptorium.Inline("gate: A guarded passage."),
+		},
+	})
+	if !errors.Is(err, scriptorium.ErrLLMGenerate) {
+		t.Fatalf("expected ErrLLMGenerate, got %v", err)
+	}
+	if !errors.Is(err, scriptorium.ErrArtifactLoad) {
+		t.Fatalf("expected preserved ErrArtifactLoad, got %v", err)
+	}
+}
+
 func TestPrepareWithoutProfileMatchesSpecificPublicError(t *testing.T) {
 	promptDir := t.TempDir()
 	writePublicPromptFile(t, promptDir, "profile-required", "")
diff --git a/errors.go b/errors.go
index 4e9ca16..6099b45 100644
--- a/errors.go
+++ b/errors.go
@@ -13,9 +13,6 @@ func mapPublicError(err error) error {
 	if err == nil {
 		return nil
 	}
-	if hasPublicError(err) {
-		return err
-	}
 	publicErr := publicErrorFor(err)
 	if publicErr == nil {
 		return err
@@ -23,28 +20,6 @@ func mapPublicError(err error) error {
 	return fmt.Errorf("%w: %w", publicErr, err)
 }
 
-func hasPublicError(err error) bool {
-	for _, publicErr := range []error{
-		ErrInvalidConfig,
-		ErrInvalidRequest,
-		ErrPromptNotFound,
-		ErrProfileNotFound,
-		ErrProfileRequired,
-		ErrPromptLoad,
-		ErrProfileLoad,
-		ErrAPIKeyEnvMissing,
-		ErrArtifactLoad,
-		ErrPromptRender,
-		ErrLLMGenerate,
-		ErrValidation,
-	} {
-		if errors.Is(err, publicErr) {
-			return true
-		}
-	}
-	return false
-}
-
 func publicErrorFor(err error) error {
 	switch {
 	case errors.Is(err, promptdef.ErrPromptDefinitionNotFound):