Validate and compose provider endpoints

engine_test.go

@@ -1857,7 +1857,7 @@ func TestPrepareWorksWithInMemoryProfilesWithoutProfileFiles(t *testing.T) {
 		SchemaDir: frameworkSchemaDir,
 	}, promptkit.WithProfiles(promptkit.Profile{
 		ID:       "memory-profile",
-		Endpoint: "http://memory-profile/v1",
+		Endpoint: "  https://memory-profile/nested/v1  ",
 		Model:    "memory-model",
 	}))
 	if err != nil {
@@ -1878,6 +1878,9 @@ func TestPrepareWorksWithInMemoryProfilesWithoutProfileFiles(t *testing.T) {
 	if prepared.EffectiveModelParams.Model != "memory-model" {
 		t.Fatalf("expected in-memory profile model, got %q", prepared.EffectiveModelParams.Model)
 	}
+	if prepared.EffectiveModelParams.Endpoint != "https://memory-profile/nested/v1" {
+		t.Fatalf("expected normalized in-memory profile endpoint, got %q", prepared.EffectiveModelParams.Endpoint)
+	}
 }
 
 func TestInMemoryProfilesOverrideBuiltInsAndProfileSources(t *testing.T) {
@@ -1961,6 +1964,79 @@ func TestWithProfilesRejectsInvalidExecutionSettings(t *testing.T) {
 	}
 }
 
+func TestEndpointValidationMapsPublicErrorCategories(t *testing.T) {
+	t.Run("backend registration is invalid configuration", func(t *testing.T) {
+		_, err := promptkit.NewEngine(
+			promptkit.Config{PromptDir: frameworkPromptDir},
+			promptkit.WithBackend(promptkit.Backend{ID: "invalid", Endpoint: "/v1"}),
+		)
+		if !errors.Is(err, promptkit.ErrInvalidConfig) {
+			t.Fatalf("expected ErrInvalidConfig, got %v", err)
+		}
+	})
+
+	t.Run("in-memory profile is invalid configuration", func(t *testing.T) {
+		_, err := promptkit.NewEngine(
+			promptkit.Config{PromptDir: frameworkPromptDir},
+			promptkit.WithProfiles(promptkit.Profile{
+				ID:       "invalid",
+				Endpoint: "https://provider.example/v1?mode=chat",
+				Model:    "model",
+			}),
+		)
+		if !errors.Is(err, promptkit.ErrInvalidConfig) {
+			t.Fatalf("expected ErrInvalidConfig, got %v", err)
+		}
+	})
+
+	t.Run("file profile is a profile-load failure", func(t *testing.T) {
+		profileFS := fstest.MapFS{
+			"profiles/invalid.yaml": &fstest.MapFile{Data: []byte(`
+id: invalid
+endpoint: 'https://provider.example/v1#chat'
+model: model
+`)},
+		}
+		engine, err := promptkit.NewEngine(
+			promptkit.Config{PromptDir: frameworkPromptDir},
+			promptkit.WithProfileFS(profileFS, "profiles"),
+		)
+		if err != nil {
+			t.Fatalf("construct engine: %v", err)
+		}
+		_, err = engine.InspectProfile(context.Background(), "invalid")
+		if !errors.Is(err, promptkit.ErrProfileLoad) {
+			t.Fatalf("expected ErrProfileLoad, got %v", err)
+		}
+	})
+
+	t.Run("request override is an invalid request", func(t *testing.T) {
+		engine, err := promptkit.NewEngine(
+			promptkit.Config{PromptDir: frameworkPromptDir},
+			promptkit.WithProfiles(promptkit.Profile{
+				ID:       "valid",
+				Endpoint: "https://provider.example/v1",
+				Model:    "model",
+			}),
+		)
+		if err != nil {
+			t.Fatalf("construct engine: %v", err)
+		}
+		_, err = engine.Prepare(context.Background(), promptkit.RunRequest{
+			PromptID:  frameworkMarkdownSummaryPromptID,
+			ProfileID: "valid",
+			Inputs: map[string]promptkit.ArtifactRef{
+				"transcript": promptkit.Inline("Rin opens the gate."),
+				"glossary":   promptkit.Inline("gate: A guarded passage."),
+			},
+			Execution: &promptkit.ExecutionTargetOverride{Endpoint: "ftp://provider.example/v1"},
+		})
+		if !errors.Is(err, promptkit.ErrInvalidRequest) {
+			t.Fatalf("expected ErrInvalidRequest, got %v", err)
+		}
+	})
+}
+
 func TestOpenAICompatibleProfileRunsThroughNormalProfilePath(t *testing.T) {
 	fake := &fakeLLMClient{response: &promptkit.GenerateResponse{Content: "ok"}}
 	prof := promptkit.OpenAICompatibleProfile(promptkit.OpenAICompatibleProfileConfig{