Simplify downstream tool configuration

internal/adapters/audita/subprocess.go

@@ -108,18 +108,14 @@ func NewSubprocessRunner(cfg SubprocessRunnerConfig) (*SubprocessRunner, error)
 			return nil, fmt.Errorf("audita module at index %d is empty", i)
 		}
 	}
-	if strings.TrimSpace(cfg.BaseURL) == "" {
-		return nil, fmt.Errorf("audita base url is required")
-	}
-	u, err := url.Parse(cfg.BaseURL)
-	if err != nil || u.Scheme == "" || u.Host == "" {
-		if err != nil {
-			return nil, fmt.Errorf("audita base url %q is invalid: %w", cfg.BaseURL, err)
+	if strings.TrimSpace(cfg.BaseURL) != "" {
+		u, err := url.Parse(cfg.BaseURL)
+		if err != nil || u.Scheme == "" || u.Host == "" {
+			if err != nil {
+				return nil, fmt.Errorf("audita base url %q is invalid: %w", cfg.BaseURL, err)
+			}
+			return nil, fmt.Errorf("audita base url %q is invalid", cfg.BaseURL)
 		}
-		return nil, fmt.Errorf("audita base url %q is invalid", cfg.BaseURL)
-	}
-	if strings.TrimSpace(cfg.Model) == "" {
-		return nil, fmt.Errorf("audita model is required")
 	}
 	if cfg.TotalLLMConcurrency != nil && *cfg.TotalLLMConcurrency <= 0 {
 		return nil, fmt.Errorf("audita total llm concurrency must be > 0 when provided")
@@ -307,10 +303,14 @@ func (r *SubprocessRunner) buildArgs(req PolishRequest, modules []string) []stri
 		req.MergedTranscriptPath,
 		"--glossary", req.GlossaryPath,
 		"--output", req.OutputProcessedPath,
-		"--base-url", r.baseURL,
-		"--model", r.model,
 		"--work-dir", req.WorkDir,
 	}
+	if r.baseURL != "" {
+		args = append(args, "--base-url", r.baseURL)
+	}
+	if r.model != "" {
+		args = append(args, "--model", r.model)
+	}
 	if len(modules) > 0 {
 		args = append(args, "--modules", strings.Join(modules, ","))
 	}

internal/adapters/audita/subprocess_test.go

@@ -99,9 +99,9 @@ func TestSubprocessRunnerSuccessArgsEnvAndValidation(t *testing.T) {
 		"process", req.MergedTranscriptPath,
 		"--glossary", req.GlossaryPath,
 		"--output", req.OutputProcessedPath,
+		"--work-dir", req.WorkDir,
 		"--base-url", "https://openrouter.ai/api/v1",
 		"--model", "openrouter/google/gemma-4-31b-it",
-		"--work-dir", req.WorkDir,
 		"--modules", "glossary,homophones,glossary",
 		"--report-json", req.ReportPath,
 		"--transcript-description", "Campaign Session 42",
@@ -248,6 +248,36 @@ func TestSubprocessRunnerOmitsModulesFlagWhenNotConfigured(t *testing.T) {
 	}
 }
 
+func TestSubprocessRunnerOmitsBaseURLAndModelFlagsWhenNotConfigured(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("helper wrapper script uses /bin/sh")
+	}
+	t.Setenv("GO_WANT_AUDITA_HELPER", "1")
+	t.Setenv("AUDITA_HELPER_MODE", "success")
+	recordPath := filepath.Join(t.TempDir(), "record.json")
+	t.Setenv("AUDITA_HELPER_RECORD_PATH", recordPath)
+
+	runner := mustAuditaRunner(t, SubprocessRunnerConfig{
+		Binary:       writeAuditaHelperWrapper(t),
+		Timeout:      mustParseAuditaDuration(t, "2s"),
+		LLMAPIKeyEnv: "",
+		Report:       false,
+	})
+	req := auditaReqForTest(t, false)
+	if _, err := runner.Run(context.Background(), req); err != nil {
+		t.Fatalf("Run() error = %v", err)
+	}
+	rec := readAuditaHelperRecord(t, recordPath)
+	for i := 0; i < len(rec.Args); i++ {
+		if rec.Args[i] == "--base-url" {
+			t.Fatalf("args contained --base-url unexpectedly: %#v", rec.Args)
+		}
+		if rec.Args[i] == "--model" {
+			t.Fatalf("args contained --model unexpectedly: %#v", rec.Args)
+		}
+	}
+}
+
 func TestSubprocessRunnerSubprocessFailure(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		t.Skip("helper wrapper script uses /bin/sh")

internal/app/runner.go

@@ -250,7 +250,7 @@ func buildDefaultAuditaRunner(cfg *config.Config) (audita.Runner, error) {
 	}
 
 	a := cfg.Pipeline.Audita
-	if strings.TrimSpace(a.Binary) == "" || strings.TrimSpace(a.Timeout) == "" || strings.TrimSpace(a.BaseURL) == "" || strings.TrimSpace(a.Model) == "" {
+	if strings.TrimSpace(a.Binary) == "" || strings.TrimSpace(a.Timeout) == "" {
 		// Compatibility fallback for tests or internal call paths that bypass config validation/defaults.
 		return &audita.NoopRunner{}, nil
 	}

internal/app/runner_test.go

@@ -497,6 +497,55 @@ func testConfig(t *testing.T) *config.Config {
 	}
 }
 
+func TestBuildDefaultRunnersWithOmittedToolSections(t *testing.T) {
+	dir := t.TempDir()
+	pipelinePath := filepath.Join(dir, "pipeline.yml")
+	sessionPath := filepath.Join(dir, "session.yml")
+	pipelineYAML := `workspace:
+  root: ` + t.TempDir() + `
+whisperx:
+  transcribe_url: https://example.com/transcribe
+analyzer:
+  timeout: 20m
+notification:
+  timeout: 10s
+`
+	sessionYAML := `session_id: 2026-05-03
+campaign: sample-campaign
+inputs:
+  audio_dir: ./audio
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml
+`
+	mustWriteFile(t, pipelinePath, pipelineYAML)
+	mustWriteFile(t, sessionPath, sessionYAML)
+
+	cfg, err := config.Load(pipelinePath, sessionPath)
+	if err != nil {
+		t.Fatalf("Load() error = %v", err)
+	}
+	if err := config.Validate(cfg); err != nil {
+		t.Fatalf("Validate() error = %v", err)
+	}
+
+	serRunner, err := buildDefaultSeriatimRunner(cfg)
+	if err != nil {
+		t.Fatalf("buildDefaultSeriatimRunner() error = %v", err)
+	}
+	if _, ok := serRunner.(*seriatim.SubprocessRunner); !ok {
+		t.Fatalf("seriatim runner type = %T, want *seriatim.SubprocessRunner", serRunner)
+	}
+
+	audRunner, err := buildDefaultAuditaRunner(cfg)
+	if err != nil {
+		t.Fatalf("buildDefaultAuditaRunner() error = %v", err)
+	}
+	if _, ok := audRunner.(*audita.SubprocessRunner); !ok {
+		t.Fatalf("audita runner type = %T, want *audita.SubprocessRunner", audRunner)
+	}
+}
+
 func mustWriteFile(t *testing.T, path, contents string) {
 	t.Helper()
 	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {

internal/config/load.go

@@ -244,6 +244,9 @@ func applySeriatimDefaults(cfg *SeriatimConfig) {
 	if cfg == nil {
 		return
 	}
+	if cfg.Binary == "" {
+		cfg.Binary = "seriatim"
+	}
 	if cfg.Timeout == "" {
 		cfg.Timeout = "10m"
 	}
@@ -262,15 +265,12 @@ func applyAuditaDefaults(cfg *AuditaConfig) {
 	if cfg == nil {
 		return
 	}
+	if cfg.Binary == "" {
+		cfg.Binary = "audita"
+	}
 	if cfg.Timeout == "" {
 		cfg.Timeout = "3h"
 	}
-	if cfg.BaseURL == "" {
-		cfg.BaseURL = "https://openrouter.ai/api/v1"
-	}
-	if cfg.Model == "" {
-		cfg.Model = "openrouter/google/gemma-4-31b-it"
-	}
 	if cfg.Report == nil {
 		cfg.Report = boolPtr(true)
 	}
@@ -280,6 +280,9 @@ func applyScriptoriumDefaults(cfg *ScriptoriumConfig) {
 	if cfg == nil {
 		return
 	}
+	if cfg.Binary == "" {
+		cfg.Binary = "scriptorium"
+	}
 	if cfg.Timeout == "" {
 		cfg.Timeout = "10m"
 	}

internal/config/load_validate_test.go

@@ -37,6 +37,26 @@ inputs:
   speakers_file: ./speakers.yml
   autocorrect_file: ./autocorrect.yml
   glossary_file: ./glossary.yml
+`,
+			checkDefault: true,
+		},
+		{
+			name: "seriatim and audita sections can be omitted",
+			pipelineYAML: `workspace:
+  root: /tmp/narratio
+whisperx:
+  transcribe_url: https://transcription.ai.rakestrawhome.com/transcribe
+analyzer:
+  timeout: 20m
+notification:
+  timeout: 15s
+`,
+			sessionYAML: `session_id: 2026-05-03
+inputs:
+  audio_dir: ./audio
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml
 `,
 			checkDefault: true,
 		},
@@ -296,7 +316,7 @@ inputs:
 			wantLoadErr: "strict decode failed",
 		},
 		{
-			name: "missing seriatim binary fails",
+			name: "missing seriatim binary uses default",
 			pipelineYAML: `workspace:
   root: /tmp/narratio
 whisperx:
@@ -311,7 +331,6 @@ inputs:
   autocorrect_file: ./autocorrect.yml
   glossary_file: ./glossary.yml
 `,
-			wantValidate: "pipeline config \"pipeline.yml\" invalid: pipeline.seriatim.binary is required",
 		},
 		{
 			name: "invalid seriatim timeout fails",
@@ -412,7 +431,7 @@ inputs:
 			wantLoadErr: "strict decode failed",
 		},
 		{
-			name: "missing audita binary fails",
+			name: "missing audita binary uses default",
 			pipelineYAML: `workspace:
   root: /tmp/narratio
 whisperx:
@@ -429,7 +448,6 @@ inputs:
   autocorrect_file: ./autocorrect.yml
   glossary_file: ./glossary.yml
 `,
-			wantValidate: "pipeline config \"pipeline.yml\" invalid: pipeline.audita.binary is required",
 		},
 		{
 			name: "invalid audita timeout fails",
@@ -713,6 +731,9 @@ inputs:
 				if cfg.Pipeline.Seriatim.Timeout != "10m" {
 					t.Fatalf("seriatim.timeout = %q, want %q", cfg.Pipeline.Seriatim.Timeout, "10m")
 				}
+				if cfg.Pipeline.Seriatim.Binary != "seriatim" {
+					t.Fatalf("seriatim.binary = %q, want %q", cfg.Pipeline.Seriatim.Binary, "seriatim")
+				}
 				if cfg.Pipeline.Seriatim.OutputSchema != "seriatim-intermediate" {
 					t.Fatalf("seriatim.output_schema = %q, want %q", cfg.Pipeline.Seriatim.OutputSchema, "seriatim-intermediate")
 				}
@@ -725,17 +746,20 @@ inputs:
 				if cfg.Pipeline.Audita.Timeout != "3h" {
 					t.Fatalf("audita.timeout = %q, want %q", cfg.Pipeline.Audita.Timeout, "3h")
 				}
+				if cfg.Pipeline.Audita.Binary != "audita" {
+					t.Fatalf("audita.binary = %q, want %q", cfg.Pipeline.Audita.Binary, "audita")
+				}
 				if cfg.Pipeline.Audita.LLMAPIKeyEnv != "" {
 					t.Fatalf("audita.llm_api_key_env = %q, want empty by default", cfg.Pipeline.Audita.LLMAPIKeyEnv)
 				}
 				if cfg.Pipeline.Audita.Modules != nil {
 					t.Fatalf("audita.modules = %#v, want nil default (optional override)", cfg.Pipeline.Audita.Modules)
 				}
-				if cfg.Pipeline.Audita.BaseURL != "https://openrouter.ai/api/v1" {
-					t.Fatalf("audita.base_url = %q, want %q", cfg.Pipeline.Audita.BaseURL, "https://openrouter.ai/api/v1")
+				if cfg.Pipeline.Audita.BaseURL != "" {
+					t.Fatalf("audita.base_url = %q, want empty default", cfg.Pipeline.Audita.BaseURL)
 				}
-				if cfg.Pipeline.Audita.Model != "openrouter/google/gemma-4-31b-it" {
-					t.Fatalf("audita.model = %q, want %q", cfg.Pipeline.Audita.Model, "openrouter/google/gemma-4-31b-it")
+				if cfg.Pipeline.Audita.Model != "" {
+					t.Fatalf("audita.model = %q, want empty default", cfg.Pipeline.Audita.Model)
 				}
 				if cfg.Pipeline.Audita.ValidationModel != "" {
 					t.Fatalf("audita.validation_model = %q, want empty default", cfg.Pipeline.Audita.ValidationModel)

internal/config/scriptorium_test.go

@@ -49,11 +49,19 @@ func TestScriptoriumLoadAndValidate(t *testing.T) {
 			wantLoadErr: "strict decode failed",
 		},
 		{
-			name: "missing binary fails when section present",
+			name: "missing binary defaults when section present",
 			scriptoriumYAML: `scriptorium:
   timeout: 10m
 `,
-			wantValidateErr: "pipeline.scriptorium.binary is required",
+			assert: func(t *testing.T, cfg *Config) {
+				t.Helper()
+				if cfg.Pipeline.Scriptorium == nil {
+					t.Fatal("scriptorium config should be present")
+				}
+				if cfg.Pipeline.Scriptorium.Binary != "scriptorium" {
+					t.Fatalf("scriptorium.binary = %q, want scriptorium", cfg.Pipeline.Scriptorium.Binary)
+				}
+			},
 		},
 		{
 			name: "enabled artifact missing prompt id fails",

internal/config/validate.go

@@ -276,9 +276,6 @@ func validateAudita(cfg AuditaConfig) error {
 			return fmt.Errorf("pipeline.audita.base_url must be a valid URL")
 		}
 	}
-	if strings.TrimSpace(cfg.Model) == "" {
-		return fmt.Errorf("pipeline.audita.model is required")
-	}
 	if cfg.TotalLLMConcurrency != nil && *cfg.TotalLLMConcurrency <= 0 {
 		return fmt.Errorf("pipeline.audita.total_llm_concurrency must be > 0")
 	}