Add render artifact model, config, and Seriatim adapter contracts

internal/adapters/seriatim/fake.go

@@ -68,6 +68,26 @@ func (n *NoopRunner) Normalize(ctx context.Context, req NormalizeRequest) (Norma
 	}, nil
 }
 
+// Render returns the requested output path with placeholder metadata.
+func (n *NoopRunner) Render(ctx context.Context, req RenderRequest) (RenderResult, error) {
+	if err := ctx.Err(); err != nil {
+		return RenderResult{}, err
+	}
+	if err := materializeRenderPlaceholders(req); err != nil {
+		return RenderResult{}, err
+	}
+	return RenderResult{
+		OutputRenderedPath:  req.OutputRenderedPath,
+		StdoutLogPath:       req.StdoutLogPath,
+		StderrLogPath:       req.StderrLogPath,
+		GeneratedConfigPath: req.GeneratedConfigPath,
+		InvokedBinary:       "noop",
+		Format:              req.Format,
+		Title:               req.Title,
+		Metadata:            map[string]any{"placeholder": true},
+	}, nil
+}
+
 // FakeRunner captures merge requests and returns deterministic responses.
 type FakeRunner struct {
 	Requests          []MergeRequest
@@ -79,6 +99,9 @@ type FakeRunner struct {
 	TrimRequests      []TrimRequest
 	TrimErr           error
 	TrimResult        TrimResult
+	RenderRequests    []RenderRequest
+	RenderErr         error
+	RenderResult      RenderResult
 }
 
 // Run records request and returns configured response.
@@ -195,6 +218,46 @@ func (f *FakeRunner) Normalize(ctx context.Context, req NormalizeRequest) (Norma
 	return res, nil
 }
 
+// Render records request and returns configured response.
+func (f *FakeRunner) Render(ctx context.Context, req RenderRequest) (RenderResult, error) {
+	if err := ctx.Err(); err != nil {
+		return RenderResult{}, err
+	}
+	f.RenderRequests = append(f.RenderRequests, req)
+	if f.RenderErr != nil {
+		return RenderResult{}, f.RenderErr
+	}
+	if err := materializeRenderPlaceholders(req); err != nil {
+		return RenderResult{}, err
+	}
+	res := f.RenderResult
+	if res.OutputRenderedPath == "" {
+		res.OutputRenderedPath = req.OutputRenderedPath
+	}
+	if res.StdoutLogPath == "" {
+		res.StdoutLogPath = req.StdoutLogPath
+	}
+	if res.StderrLogPath == "" {
+		res.StderrLogPath = req.StderrLogPath
+	}
+	if res.GeneratedConfigPath == "" {
+		res.GeneratedConfigPath = req.GeneratedConfigPath
+	}
+	if res.InvokedBinary == "" {
+		res.InvokedBinary = "fake"
+	}
+	if res.Format == "" {
+		res.Format = req.Format
+	}
+	if res.Title == "" {
+		res.Title = req.Title
+	}
+	if res.Metadata == nil {
+		res.Metadata = map[string]any{"fake": true}
+	}
+	return res, nil
+}
+
 func materializePlaceholders(req MergeRequest) error {
 	if req.OutputMergedTranscriptPath != "" {
 		if err := subprocess.WriteFileAtomic(req.OutputMergedTranscriptPath, []byte(`{"schema":"seriatim.intermediate.v1","segments":[]}`), 0o644); err != nil {
@@ -301,3 +364,39 @@ func materializeNormalizePlaceholders(req NormalizeRequest) error {
 	}
 	return nil
 }
+
+func materializeRenderPlaceholders(req RenderRequest) error {
+	if req.OutputRenderedPath != "" {
+		if err := subprocess.WriteFileAtomic(req.OutputRenderedPath, []byte("# Transcript\n\nRendered markdown placeholder.\n"), 0o644); err != nil {
+			return fmt.Errorf("write rendered transcript %q: %w", req.OutputRenderedPath, err)
+		}
+	}
+	if req.GeneratedConfigPath != "" {
+		payload := map[string]any{
+			"schema":              "seriatim.generated.v1",
+			"placeholder":         true,
+			"command":             "render",
+			"input_path":          req.InputTranscriptPath,
+			"output_path":         req.OutputRenderedPath,
+			"format":              req.Format,
+			"title":               req.Title,
+			"include_timestamps":  req.IncludeTimestamps,
+			"include_segment_ids": req.IncludeSegmentIDs,
+			"include_metadata":    req.IncludeMetadata,
+		}
+		if err := subprocess.WriteYAMLAtomic(req.GeneratedConfigPath, payload, 0o644); err != nil {
+			return fmt.Errorf("write generated config %q: %w", req.GeneratedConfigPath, err)
+		}
+	}
+	if req.StdoutLogPath != "" {
+		if err := subprocess.WriteFileAtomic(req.StdoutLogPath, []byte("seriatim noop/fake render stdout placeholder\n"), 0o644); err != nil {
+			return fmt.Errorf("write stdout log %q: %w", req.StdoutLogPath, err)
+		}
+	}
+	if req.StderrLogPath != "" {
+		if err := subprocess.WriteFileAtomic(req.StderrLogPath, []byte("seriatim noop/fake render stderr placeholder\n"), 0o644); err != nil {
+			return fmt.Errorf("write stderr log %q: %w", req.StderrLogPath, err)
+		}
+	}
+	return nil
+}

internal/adapters/seriatim/fake_test.go

@@ -148,3 +148,58 @@ func TestFakeRunnerNormalizeError(t *testing.T) {
 		t.Fatal("expected error, got nil")
 	}
 }
+
+func TestFakeRunnerRenderCapturesRequestAndReturnsPath(t *testing.T) {
+	fake := &FakeRunner{}
+	dir := t.TempDir()
+	req := RenderRequest{
+		GeneratedConfigPath: filepath.Join(dir, "config", "seriatim.render.yml"),
+		InputTranscriptPath: filepath.Join(dir, "transcripts", "final.trimmed.json"),
+		OutputRenderedPath:  filepath.Join(dir, "transcripts", "final.trimmed.md"),
+		Format:              "markdown",
+		Title:               "Session render",
+		IncludeTimestamps:   true,
+		IncludeSegmentIDs:   false,
+		IncludeMetadata:     true,
+		StdoutLogPath:       filepath.Join(dir, "logs", "seriatim.render.stdout.log"),
+		StderrLogPath:       filepath.Join(dir, "logs", "seriatim.render.stderr.log"),
+	}
+
+	res, err := fake.Render(context.Background(), req)
+	if err != nil {
+		t.Fatalf("Render() error = %v", err)
+	}
+	if len(fake.RenderRequests) != 1 || fake.RenderRequests[0].GeneratedConfigPath == "" {
+		t.Fatalf("render requests = %#v, want captured request", fake.RenderRequests)
+	}
+	if res.OutputRenderedPath != req.OutputRenderedPath {
+		t.Fatalf("rendered path = %q, want %q", res.OutputRenderedPath, req.OutputRenderedPath)
+	}
+	if res.Format != req.Format {
+		t.Fatalf("format = %q, want %q", res.Format, req.Format)
+	}
+	if res.Title != req.Title {
+		t.Fatalf("title = %q, want %q", res.Title, req.Title)
+	}
+
+	cfgData, err := os.ReadFile(req.GeneratedConfigPath)
+	if err != nil {
+		t.Fatalf("read generated config: %v", err)
+	}
+	if !strings.Contains(string(cfgData), "command: render") {
+		t.Fatalf("generated config = %q, want render command marker", string(cfgData))
+	}
+	for _, path := range []string{req.StdoutLogPath, req.StderrLogPath, req.OutputRenderedPath} {
+		if _, err := os.Stat(path); err != nil {
+			t.Fatalf("expected file %q to exist: %v", path, err)
+		}
+	}
+}
+
+func TestFakeRunnerRenderError(t *testing.T) {
+	fake := &FakeRunner{RenderErr: errors.New("boom")}
+	_, err := fake.Render(context.Background(), RenderRequest{})
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+}

internal/adapters/seriatim/runner.go

@@ -1,4 +1,4 @@
-// Package seriatim declares the adapter contract for transcript merge/normalize/trim execution.
+// Package seriatim declares the adapter contract for transcript merge/normalize/trim/render execution.
 package seriatim
 
 import (
@@ -6,11 +6,12 @@ import (
 	"time"
 )
 
-// Runner is the adapter boundary for seriatim merge/normalize/trim invocations.
+// Runner is the adapter boundary for seriatim merge/normalize/trim/render invocations.
 type Runner interface {
 	Run(ctx context.Context, req MergeRequest) (MergeResult, error)
 	Normalize(ctx context.Context, req NormalizeRequest) (NormalizeResult, error)
 	Trim(ctx context.Context, req TrimRequest) (TrimResult, error)
+	Render(ctx context.Context, req RenderRequest) (RenderResult, error)
 }
 
 // MergeRequest describes a seriatim merge invocation.
@@ -90,3 +91,33 @@ type TrimResult struct {
 	KeepSelector        string
 	Metadata            map[string]any
 }
+
+// RenderRequest describes a seriatim render invocation.
+type RenderRequest struct {
+	Binary              string
+	InputTranscriptPath string
+	OutputRenderedPath  string
+	Format              string
+	Title               string
+	IncludeTimestamps   bool
+	IncludeSegmentIDs   bool
+	IncludeMetadata     bool
+	StdoutLogPath       string
+	StderrLogPath       string
+	GeneratedConfigPath string
+	Timeout             time.Duration
+}
+
+// RenderResult describes a render output.
+type RenderResult struct {
+	OutputRenderedPath  string
+	StdoutLogPath       string
+	StderrLogPath       string
+	GeneratedConfigPath string
+	ExitCode            int
+	Duration            time.Duration
+	InvokedBinary       string
+	Format              string
+	Title               string
+	Metadata            map[string]any
+}

internal/adapters/seriatim/subprocess.go

@@ -8,6 +8,7 @@ import (
 	"strconv"
 	"strings"
 	"time"
+	"unicode/utf8"
 
 	"gitea.maximumdirect.net/eric/narratio/internal/adapters/subprocess"
 )
@@ -384,6 +385,96 @@ func (r *SubprocessRunner) Normalize(ctx context.Context, req NormalizeRequest)
 	}, nil
 }
 
+// Render executes Seriatim render with deterministic flags and validates non-empty text output.
+func (r *SubprocessRunner) Render(ctx context.Context, req RenderRequest) (RenderResult, error) {
+	if r == nil {
+		return RenderResult{}, fmt.Errorf("seriatim subprocess runner is nil")
+	}
+	if strings.TrimSpace(req.InputTranscriptPath) == "" {
+		return RenderResult{}, fmt.Errorf("seriatim render input path is required")
+	}
+	if strings.TrimSpace(req.OutputRenderedPath) == "" {
+		return RenderResult{}, fmt.Errorf("seriatim render output path is required")
+	}
+	format := strings.TrimSpace(req.Format)
+	if format == "" {
+		format = "markdown"
+	}
+	if format != "markdown" {
+		return RenderResult{}, fmt.Errorf("seriatim render format %q is unsupported", req.Format)
+	}
+
+	binary := r.binary
+	if strings.TrimSpace(req.Binary) != "" {
+		binary = strings.TrimSpace(req.Binary)
+	}
+
+	timeout := r.timeout
+	if req.Timeout < 0 {
+		return RenderResult{}, fmt.Errorf("seriatim render timeout must be >= 0")
+	}
+	if req.Timeout > 0 {
+		timeout = req.Timeout
+	}
+
+	args := buildRenderArgs(req, format)
+	if req.GeneratedConfigPath != "" {
+		if err := writeRenderInvocationConfig(req, args, binary, timeout, format); err != nil {
+			return RenderResult{}, fmt.Errorf("write seriatim render invocation config %q: %w", req.GeneratedConfigPath, err)
+		}
+	}
+
+	runRes, err := subprocess.Run(ctx, subprocess.RunRequest{
+		Executable:    binary,
+		Args:          args,
+		Timeout:       timeout,
+		StdoutLogPath: req.StdoutLogPath,
+		StderrLogPath: req.StderrLogPath,
+	})
+	if err != nil {
+		return RenderResult{
+			OutputRenderedPath:  req.OutputRenderedPath,
+			StdoutLogPath:       req.StdoutLogPath,
+			StderrLogPath:       req.StderrLogPath,
+			GeneratedConfigPath: req.GeneratedConfigPath,
+			ExitCode:            runRes.ExitCode,
+			Duration:            runRes.Duration,
+			InvokedBinary:       binary,
+			Format:              format,
+			Title:               req.Title,
+		}, fmt.Errorf("run seriatim render (binary=%q): %w", binary, err)
+	}
+
+	if err := validateNonEmptyTextFile(req.OutputRenderedPath); err != nil {
+		return RenderResult{
+			OutputRenderedPath:  req.OutputRenderedPath,
+			StdoutLogPath:       req.StdoutLogPath,
+			StderrLogPath:       req.StderrLogPath,
+			GeneratedConfigPath: req.GeneratedConfigPath,
+			ExitCode:            runRes.ExitCode,
+			Duration:            runRes.Duration,
+			InvokedBinary:       binary,
+			Format:              format,
+			Title:               req.Title,
+		}, fmt.Errorf("validate seriatim rendered output %q: %w", req.OutputRenderedPath, err)
+	}
+
+	return RenderResult{
+		OutputRenderedPath:  req.OutputRenderedPath,
+		StdoutLogPath:       req.StdoutLogPath,
+		StderrLogPath:       req.StderrLogPath,
+		GeneratedConfigPath: req.GeneratedConfigPath,
+		ExitCode:            runRes.ExitCode,
+		Duration:            runRes.Duration,
+		InvokedBinary:       binary,
+		Format:              format,
+		Title:               req.Title,
+		Metadata: map[string]any{
+			"adapter": "seriatim_subprocess",
+		},
+	}, nil
+}
+
 func (r *SubprocessRunner) buildMergeArgs(req MergeRequest) []string {
 	args := []string{"merge"}
 
@@ -480,6 +571,22 @@ func buildNormalizeArgs(req NormalizeRequest, outputSchema string) []string {
 	return args
 }
 
+func buildRenderArgs(req RenderRequest, format string) []string {
+	args := []string{
+		"render",
+		"--input-file", req.InputTranscriptPath,
+		"--output-file", req.OutputRenderedPath,
+		"--format", format,
+		"--include-timestamps", strconv.FormatBool(req.IncludeTimestamps),
+		"--include-segment-ids", strconv.FormatBool(req.IncludeSegmentIDs),
+		"--include-metadata", strconv.FormatBool(req.IncludeMetadata),
+	}
+	if strings.TrimSpace(req.Title) != "" {
+		args = append(args, "--title", req.Title)
+	}
+	return args
+}
+
 func writeTrimInvocationConfig(req TrimRequest, args []string, binary string, timeout time.Duration) error {
 	payload := map[string]any{
 		"schema":        "seriatim.generated.v1",
@@ -509,6 +616,24 @@ func writeNormalizeInvocationConfig(req NormalizeRequest, args []string, binary
 	return subprocess.WriteYAMLAtomic(req.GeneratedConfigPath, payload, 0o644)
 }
 
+func writeRenderInvocationConfig(req RenderRequest, args []string, binary string, timeout time.Duration, format string) error {
+	payload := map[string]any{
+		"schema":              "seriatim.generated.v1",
+		"command":             "render",
+		"binary":              binary,
+		"args":                args,
+		"timeout":             timeout.String(),
+		"input_path":          req.InputTranscriptPath,
+		"output_path":         req.OutputRenderedPath,
+		"format":              format,
+		"title":               req.Title,
+		"include_timestamps":  req.IncludeTimestamps,
+		"include_segment_ids": req.IncludeSegmentIDs,
+		"include_metadata":    req.IncludeMetadata,
+	}
+	return subprocess.WriteYAMLAtomic(req.GeneratedConfigPath, payload, 0o644)
+}
+
 func validateJSONFile(path string) error {
 	data, err := os.ReadFile(path)
 	if err != nil {
@@ -541,3 +666,20 @@ func validateJSONFileWithSegments(path string) error {
 	}
 	return nil
 }
+
+func validateNonEmptyTextFile(path string) error {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return fmt.Errorf("read file: %w", err)
+	}
+	if len(data) == 0 {
+		return fmt.Errorf("file is empty")
+	}
+	if !utf8.Valid(data) {
+		return fmt.Errorf("file is not valid utf-8 text")
+	}
+	if strings.TrimSpace(string(data)) == "" {
+		return fmt.Errorf("file has no non-whitespace content")
+	}
+	return nil
+}

internal/adapters/seriatim/subprocess_test.go

@@ -569,6 +569,156 @@ func TestSubprocessRunnerNormalizeInvalidReportJSONFails(t *testing.T) {
 	}
 }
 
+func TestSubprocessRunnerRenderSuccessInvocationAndProvenance(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("helper wrapper script uses /bin/sh")
+	}
+
+	t.Setenv("GO_WANT_SERIATIM_HELPER", "1")
+	t.Setenv("SERIATIM_HELPER_MODE", "render_success")
+	recordPath := filepath.Join(t.TempDir(), "record.json")
+	t.Setenv("SERIATIM_HELPER_RECORD_PATH", recordPath)
+
+	wrapper := writeHelperWrapper(t)
+	runner := mustRunner(t, wrapper, false)
+	req := renderReqForTest(t)
+
+	res, err := runner.Render(context.Background(), req)
+	if err != nil {
+		t.Fatalf("Render() error = %v", err)
+	}
+	if res.OutputRenderedPath != req.OutputRenderedPath {
+		t.Fatalf("OutputRenderedPath = %q, want %q", res.OutputRenderedPath, req.OutputRenderedPath)
+	}
+	if res.Format != req.Format {
+		t.Fatalf("Format = %q, want %q", res.Format, req.Format)
+	}
+	if res.Title != req.Title {
+		t.Fatalf("Title = %q, want %q", res.Title, req.Title)
+	}
+	if res.InvokedBinary != wrapper {
+		t.Fatalf("InvokedBinary = %q, want %q", res.InvokedBinary, wrapper)
+	}
+	if res.ExitCode != 0 {
+		t.Fatalf("ExitCode = %d, want 0", res.ExitCode)
+	}
+	if res.Duration <= 0 {
+		t.Fatalf("Duration = %s, want >0", res.Duration)
+	}
+	if res.Metadata == nil || res.Metadata["adapter"] != "seriatim_subprocess" {
+		t.Fatalf("Metadata = %#v, want adapter marker", res.Metadata)
+	}
+
+	if _, err := os.Stat(req.OutputRenderedPath); err != nil {
+		t.Fatalf("rendered output missing: %v", err)
+	}
+	if _, err := os.Stat(req.StdoutLogPath); err != nil {
+		t.Fatalf("stdout log missing: %v", err)
+	}
+	if _, err := os.Stat(req.StderrLogPath); err != nil {
+		t.Fatalf("stderr log missing: %v", err)
+	}
+	if _, err := os.Stat(req.GeneratedConfigPath); err != nil {
+		t.Fatalf("generated config missing: %v", err)
+	}
+
+	rec := readHelperRecord(t, recordPath)
+	wantArgs := []string{
+		"render",
+		"--input-file", req.InputTranscriptPath,
+		"--output-file", req.OutputRenderedPath,
+		"--format", req.Format,
+		"--include-timestamps", "true",
+		"--include-segment-ids", "false",
+		"--include-metadata", "true",
+		"--title", req.Title,
+	}
+	if strings.Join(rec.Args, "\n") != strings.Join(wantArgs, "\n") {
+		t.Fatalf("args = %#v, want %#v", rec.Args, wantArgs)
+	}
+}
+
+func TestSubprocessRunnerRenderWithoutTitleOmitsTitleArg(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("helper wrapper script uses /bin/sh")
+	}
+	t.Setenv("GO_WANT_SERIATIM_HELPER", "1")
+	t.Setenv("SERIATIM_HELPER_MODE", "render_success")
+	recordPath := filepath.Join(t.TempDir(), "record.json")
+	t.Setenv("SERIATIM_HELPER_RECORD_PATH", recordPath)
+
+	runner := mustRunner(t, writeHelperWrapper(t), false)
+	req := renderReqForTest(t)
+	req.Title = ""
+	if _, err := runner.Render(context.Background(), req); err != nil {
+		t.Fatalf("Render() error = %v", err)
+	}
+
+	rec := readHelperRecord(t, recordPath)
+	for i := 0; i < len(rec.Args); i++ {
+		if rec.Args[i] == "--title" {
+			t.Fatalf("args = %#v, did not expect --title", rec.Args)
+		}
+	}
+}
+
+func TestSubprocessRunnerRenderSubprocessFailure(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("helper wrapper script uses /bin/sh")
+	}
+	t.Setenv("GO_WANT_SERIATIM_HELPER", "1")
+	t.Setenv("SERIATIM_HELPER_MODE", "fail")
+	t.Setenv("SERIATIM_HELPER_RECORD_PATH", filepath.Join(t.TempDir(), "record.json"))
+
+	runner := mustRunner(t, writeHelperWrapper(t), false)
+	req := renderReqForTest(t)
+	_, err := runner.Render(context.Background(), req)
+	if err == nil {
+		t.Fatal("Render() error = nil, want non-nil")
+	}
+	if !strings.Contains(err.Error(), "run seriatim render") {
+		t.Fatalf("error = %q, want subprocess context", err.Error())
+	}
+}
+
+func TestSubprocessRunnerRenderMissingOutputFails(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("helper wrapper script uses /bin/sh")
+	}
+	t.Setenv("GO_WANT_SERIATIM_HELPER", "1")
+	t.Setenv("SERIATIM_HELPER_MODE", "missing_output")
+	t.Setenv("SERIATIM_HELPER_RECORD_PATH", filepath.Join(t.TempDir(), "record.json"))
+
+	runner := mustRunner(t, writeHelperWrapper(t), false)
+	req := renderReqForTest(t)
+	_, err := runner.Render(context.Background(), req)
+	if err == nil {
+		t.Fatal("Render() error = nil, want non-nil")
+	}
+	if !strings.Contains(err.Error(), "validate seriatim rendered output") {
+		t.Fatalf("error = %q, want output validation context", err.Error())
+	}
+}
+
+func TestSubprocessRunnerRenderEmptyOutputFails(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("helper wrapper script uses /bin/sh")
+	}
+	t.Setenv("GO_WANT_SERIATIM_HELPER", "1")
+	t.Setenv("SERIATIM_HELPER_MODE", "render_empty_output")
+	t.Setenv("SERIATIM_HELPER_RECORD_PATH", filepath.Join(t.TempDir(), "record.json"))
+
+	runner := mustRunner(t, writeHelperWrapper(t), false)
+	req := renderReqForTest(t)
+	_, err := runner.Render(context.Background(), req)
+	if err == nil {
+		t.Fatal("Render() error = nil, want non-nil")
+	}
+	if !strings.Contains(err.Error(), "file is empty") {
+		t.Fatalf("error = %q, want empty-file validation", err.Error())
+	}
+}
+
 func TestSubprocessRunnerConstructorValidation(t *testing.T) {
 	_, err := NewSubprocessRunnerFromConfigValues("", "10m", "seriatim-intermediate", nil, true, EnvConfig{})
 	if err == nil {
@@ -702,6 +852,14 @@ func TestSeriatimSubprocessHelper(t *testing.T) {
 	case "normalize_report_missing":
 		writeSeriatimHelperFile(outputPath, `{"schema":"seriatim.intermediate.v1","segments":[]}`)
 		os.Exit(0)
+	case "render_success":
+		writeSeriatimHelperFile(outputPath, "# Rendered transcript\n\nHello.\n")
+		_, _ = os.Stdout.WriteString("seriatim helper render stdout\n")
+		_, _ = os.Stderr.WriteString("seriatim helper render stderr\n")
+		os.Exit(0)
+	case "render_empty_output":
+		writeSeriatimHelperFile(outputPath, "")
+		os.Exit(0)
 	default:
 		_, _ = os.Stderr.WriteString(fmt.Sprintf("unknown helper mode %q\n", mode))
 		os.Exit(2)
@@ -777,6 +935,25 @@ func normalizeReqForTest(t *testing.T, withReport bool) NormalizeRequest {
 	return req
 }
 
+func renderReqForTest(t *testing.T) RenderRequest {
+	t.Helper()
+	dir := t.TempDir()
+	input := filepath.Join(dir, "final.trimmed.json")
+	writeSeriatimFile(t, input, `{"schema":"seriatim.intermediate.v1","segments":[]}`)
+	return RenderRequest{
+		InputTranscriptPath: input,
+		OutputRenderedPath:  filepath.Join(dir, "final.trimmed.md"),
+		Format:              "markdown",
+		Title:               "Session 42",
+		IncludeTimestamps:   true,
+		IncludeSegmentIDs:   false,
+		IncludeMetadata:     true,
+		GeneratedConfigPath: filepath.Join(dir, "seriatim.render.generated.yml"),
+		StdoutLogPath:       filepath.Join(dir, "seriatim.render.stdout.log"),
+		StderrLogPath:       filepath.Join(dir, "seriatim.render.stderr.log"),
+	}
+}
+
 func mustRunner(t *testing.T, binary string, report bool) *SubprocessRunner {
 	t.Helper()
 	coalesce := 3.0

internal/app/operator_artifact_rendering.go

@@ -32,15 +32,10 @@ func buildHelperArtifactCatalog(cfg *config.Config) (*artifacts.ArtifactCatalog,
 func writeArtifactList(out io.Writer, cfg *config.Config, catalog *artifacts.ArtifactCatalog, locks *effectiveLocks, publishedRemoteState map[string]string) {
 	lockSet := lockSourceSet(locks.All)
 	fmt.Fprintln(out, "Built-in:")
-	for _, id := range []string{
-		artifacts.ArtifactTranscriptBase,
-		artifacts.ArtifactTranscriptPolished,
-		artifacts.ArtifactTranscriptFinal,
-		artifacts.ArtifactTranscriptFinalTrimmed,
-		artifacts.ArtifactBoundsSession,
-	} {
-		writeArtifactLine(out, id, lockSet)
+	for _, transcript := range artifacts.RuntimeTranscriptArtifacts() {
+		writeArtifactLine(out, transcript.SourceID, lockSet)
 	}
+	writeArtifactLine(out, artifacts.ArtifactBoundsSession, lockSet)
 	fmt.Fprintln(out, "Configured:")
 	for _, entry := range catalog.ListConfigured() {
 		writeArtifactLine(out, entry.SourceID, lockSet)

internal/artifactmodel/transcripts.go

@@ -3,24 +3,30 @@ package artifactmodel
 import "strings"
 
 const (
-	SourceTranscriptBase         = "narratio.transcript.base"
-	SourceTranscriptPolished     = "narratio.transcript.polished"
-	SourceTranscriptFinal        = "narratio.transcript.final"
-	SourceTranscriptFinalTrimmed = "narratio.transcript.final_trimmed"
+	SourceTranscriptBase                 = "narratio.transcript.base"
+	SourceTranscriptPolished             = "narratio.transcript.polished"
+	SourceTranscriptFinal                = "narratio.transcript.final"
+	SourceTranscriptFinalTrimmed         = "narratio.transcript.final_trimmed"
+	SourceTranscriptFinalMarkdown        = "narratio.transcript.final_markdown"
+	SourceTranscriptFinalTrimmedMarkdown = "narratio.transcript.final_trimmed_markdown"
 )
 
 const (
-	TranscriptPathBase         = "transcripts/base.json"
-	TranscriptPathPolished     = "transcripts/polished.json"
-	TranscriptPathFinal        = "transcripts/final.json"
-	TranscriptPathFinalTrimmed = "transcripts/final.trimmed.json"
+	TranscriptPathBase                 = "transcripts/base.json"
+	TranscriptPathPolished             = "transcripts/polished.json"
+	TranscriptPathFinal                = "transcripts/final.json"
+	TranscriptPathFinalTrimmed         = "transcripts/final.trimmed.json"
+	TranscriptPathFinalMarkdown        = "transcripts/final.md"
+	TranscriptPathFinalTrimmedMarkdown = "transcripts/final.trimmed.md"
 )
 
 const (
-	TranscriptOutputKindBase         = "transcript_base"
-	TranscriptOutputKindPolished     = "transcript_polished"
-	TranscriptOutputKindFinal        = "transcript_final"
-	TranscriptOutputKindFinalTrimmed = "transcript_final_trimmed"
+	TranscriptOutputKindBase                 = "transcript_base"
+	TranscriptOutputKindPolished             = "transcript_polished"
+	TranscriptOutputKindFinal                = "transcript_final"
+	TranscriptOutputKindFinalTrimmed         = "transcript_final_trimmed"
+	TranscriptOutputKindFinalMarkdown        = "transcript_final_markdown"
+	TranscriptOutputKindFinalTrimmedMarkdown = "transcript_final_trimmed_markdown"
 )
 
 // TranscriptArtifactSpec describes one built-in transcript artifact mapping.
@@ -56,6 +62,18 @@ var runtimeTranscriptArtifacts = []TranscriptArtifactSpec{
 		ProducerStage:    "trim",
 		OutputKind:       TranscriptOutputKindFinalTrimmed,
 	},
+	{
+		SourceID:         SourceTranscriptFinalMarkdown,
+		CanonicalRelPath: TranscriptPathFinalMarkdown,
+		ProducerStage:    "render",
+		OutputKind:       TranscriptOutputKindFinalMarkdown,
+	},
+	{
+		SourceID:         SourceTranscriptFinalTrimmedMarkdown,
+		CanonicalRelPath: TranscriptPathFinalTrimmedMarkdown,
+		ProducerStage:    "render",
+		OutputKind:       TranscriptOutputKindFinalTrimmedMarkdown,
+	},
 }
 
 // RuntimeTranscriptArtifacts returns transcript mappings in pipeline order.

internal/artifactmodel/transcripts_test.go

@@ -0,0 +1,60 @@
+package artifactmodel
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestRuntimeTranscriptArtifactsIncludesMarkdownOutputs(t *testing.T) {
+	want := []TranscriptArtifactSpec{
+		{
+			SourceID:         SourceTranscriptBase,
+			CanonicalRelPath: TranscriptPathBase,
+			ProducerStage:    "merge",
+			OutputKind:       TranscriptOutputKindBase,
+		},
+		{
+			SourceID:         SourceTranscriptPolished,
+			CanonicalRelPath: TranscriptPathPolished,
+			ProducerStage:    "polish",
+			OutputKind:       TranscriptOutputKindPolished,
+		},
+		{
+			SourceID:         SourceTranscriptFinal,
+			CanonicalRelPath: TranscriptPathFinal,
+			ProducerStage:    "normalize",
+			OutputKind:       TranscriptOutputKindFinal,
+		},
+		{
+			SourceID:         SourceTranscriptFinalTrimmed,
+			CanonicalRelPath: TranscriptPathFinalTrimmed,
+			ProducerStage:    "trim",
+			OutputKind:       TranscriptOutputKindFinalTrimmed,
+		},
+		{
+			SourceID:         SourceTranscriptFinalMarkdown,
+			CanonicalRelPath: TranscriptPathFinalMarkdown,
+			ProducerStage:    "render",
+			OutputKind:       TranscriptOutputKindFinalMarkdown,
+		},
+		{
+			SourceID:         SourceTranscriptFinalTrimmedMarkdown,
+			CanonicalRelPath: TranscriptPathFinalTrimmedMarkdown,
+			ProducerStage:    "render",
+			OutputKind:       TranscriptOutputKindFinalTrimmedMarkdown,
+		},
+	}
+
+	got := RuntimeTranscriptArtifacts()
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("RuntimeTranscriptArtifacts() = %#v, want %#v", got, want)
+	}
+}
+
+func TestLookupRuntimeTranscriptArtifactFindsMarkdownOutputs(t *testing.T) {
+	for _, source := range []string{SourceTranscriptFinalMarkdown, SourceTranscriptFinalTrimmedMarkdown} {
+		if _, ok := LookupRuntimeTranscriptArtifact(source); !ok {
+			t.Fatalf("LookupRuntimeTranscriptArtifact(%q) ok=false, want true", source)
+		}
+	}
+}

internal/artifacts/artifact_resolver.go

@@ -14,28 +14,34 @@ import (
 )
 
 const (
-	ArtifactTranscriptBase         = artifactmodel.SourceTranscriptBase
-	ArtifactTranscriptPolished     = artifactmodel.SourceTranscriptPolished
-	ArtifactTranscriptFinal        = artifactmodel.SourceTranscriptFinal
-	ArtifactTranscriptFinalTrimmed = artifactmodel.SourceTranscriptFinalTrimmed
-	ArtifactBoundsSession          = "narratio.bounds.session"
+	ArtifactTranscriptBase                 = artifactmodel.SourceTranscriptBase
+	ArtifactTranscriptPolished             = artifactmodel.SourceTranscriptPolished
+	ArtifactTranscriptFinal                = artifactmodel.SourceTranscriptFinal
+	ArtifactTranscriptFinalTrimmed         = artifactmodel.SourceTranscriptFinalTrimmed
+	ArtifactTranscriptFinalMarkdown        = artifactmodel.SourceTranscriptFinalMarkdown
+	ArtifactTranscriptFinalTrimmedMarkdown = artifactmodel.SourceTranscriptFinalTrimmedMarkdown
+	ArtifactBoundsSession                  = "narratio.bounds.session"
 
 	ArtifactProvenancePreviousCacheManifestInput = "manifest.inputs.previous_cache"
 	ArtifactProvenancePreviousCacheFilesystem    = "current_session.previous_cache"
 )
 
 const (
-	TranscriptPathBase         = artifactmodel.TranscriptPathBase
-	TranscriptPathPolished     = artifactmodel.TranscriptPathPolished
-	TranscriptPathFinal        = artifactmodel.TranscriptPathFinal
-	TranscriptPathFinalTrimmed = artifactmodel.TranscriptPathFinalTrimmed
+	TranscriptPathBase                 = artifactmodel.TranscriptPathBase
+	TranscriptPathPolished             = artifactmodel.TranscriptPathPolished
+	TranscriptPathFinal                = artifactmodel.TranscriptPathFinal
+	TranscriptPathFinalTrimmed         = artifactmodel.TranscriptPathFinalTrimmed
+	TranscriptPathFinalMarkdown        = artifactmodel.TranscriptPathFinalMarkdown
+	TranscriptPathFinalTrimmedMarkdown = artifactmodel.TranscriptPathFinalTrimmedMarkdown
 )
 
 const (
-	TranscriptOutputKindBase         = artifactmodel.TranscriptOutputKindBase
-	TranscriptOutputKindPolished     = artifactmodel.TranscriptOutputKindPolished
-	TranscriptOutputKindFinal        = artifactmodel.TranscriptOutputKindFinal
-	TranscriptOutputKindFinalTrimmed = artifactmodel.TranscriptOutputKindFinalTrimmed
+	TranscriptOutputKindBase                 = artifactmodel.TranscriptOutputKindBase
+	TranscriptOutputKindPolished             = artifactmodel.TranscriptOutputKindPolished
+	TranscriptOutputKindFinal                = artifactmodel.TranscriptOutputKindFinal
+	TranscriptOutputKindFinalTrimmed         = artifactmodel.TranscriptOutputKindFinalTrimmed
+	TranscriptOutputKindFinalMarkdown        = artifactmodel.TranscriptOutputKindFinalMarkdown
+	TranscriptOutputKindFinalTrimmedMarkdown = artifactmodel.TranscriptOutputKindFinalTrimmedMarkdown
 )
 
 // ErrSessionArtifactNotFound is returned when no readable artifact exists for a known ID.
@@ -67,7 +73,7 @@ func buildArtifactRegistry() map[string]artifactSpec {
 			CanonicalRelPath: transcript.CanonicalRelPath,
 			ProducerStage:    transcript.ProducerStage,
 			OutputKind:       transcript.OutputKind,
-			ContentKind:      contentTranscriptJSON,
+			ContentKind:      transcriptContentKind(transcript),
 		}
 	}
 	registry[ArtifactBoundsSession] = artifactSpec{
@@ -80,6 +86,15 @@ func buildArtifactRegistry() map[string]artifactSpec {
 	return registry
 }
 
+func transcriptContentKind(transcript TranscriptArtifactSpec) artifactContentKind {
+	switch transcript.SourceID {
+	case ArtifactTranscriptFinalMarkdown, ArtifactTranscriptFinalTrimmedMarkdown:
+		return contentText
+	default:
+		return contentTranscriptJSON
+	}
+}
+
 // ResolvedSessionArtifact describes one session-level artifact lookup result.
 type ResolvedSessionArtifact struct {
 	ID            string

internal/artifacts/artifact_resolver_test.go

@@ -211,6 +211,29 @@ func TestResolveSessionArtifactFallsBackToCanonicalPath(t *testing.T) {
 	}
 }
 
+func TestResolveSessionArtifactFallsBackToCanonicalMarkdownPath(t *testing.T) {
+	workspace := t.TempDir()
+	paths := buildSessionPaths(workspace, "campaign", "session")
+	canonicalPath := filepath.Join(paths.TranscriptsDir, "final.md")
+	if err := os.MkdirAll(filepath.Dir(canonicalPath), 0o755); err != nil {
+		t.Fatalf("MkdirAll() error = %v", err)
+	}
+	if err := os.WriteFile(canonicalPath, []byte("# Final transcript\n"), 0o644); err != nil {
+		t.Fatalf("WriteFile() error = %v", err)
+	}
+
+	resolved, err := ResolveSessionArtifact(paths, nil, ArtifactTranscriptFinalMarkdown)
+	if err != nil {
+		t.Fatalf("ResolveSessionArtifact() error = %v", err)
+	}
+	if resolved.Path != canonicalPath {
+		t.Fatalf("resolved path = %q, want %q", resolved.Path, canonicalPath)
+	}
+	if resolved.Provenance != "fallback.canonical_path" {
+		t.Fatalf("provenance = %q, want fallback.canonical_path", resolved.Provenance)
+	}
+}
+
 func TestResolveSessionArtifactMissingReturnsTypedError(t *testing.T) {
 	workspace := t.TempDir()
 	paths := buildSessionPaths(workspace, "campaign", "session")
@@ -244,6 +267,26 @@ func TestResolveSessionArtifactValidatesTranscriptShape(t *testing.T) {
 	}
 }
 
+func TestResolveSessionArtifactRejectsEmptyMarkdownContent(t *testing.T) {
+	workspace := t.TempDir()
+	paths := buildSessionPaths(workspace, "campaign", "session")
+	canonicalPath := filepath.Join(paths.TranscriptsDir, "final.trimmed.md")
+	if err := os.MkdirAll(filepath.Dir(canonicalPath), 0o755); err != nil {
+		t.Fatalf("MkdirAll() error = %v", err)
+	}
+	if err := os.WriteFile(canonicalPath, []byte{}, 0o644); err != nil {
+		t.Fatalf("WriteFile() error = %v", err)
+	}
+
+	_, err := ResolveSessionArtifact(paths, nil, ArtifactTranscriptFinalTrimmedMarkdown)
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "file is empty") {
+		t.Fatalf("error = %q, want empty file validation", err.Error())
+	}
+}
+
 func TestResolveSessionArtifactWithCatalogBuiltInBehaviorUnchanged(t *testing.T) {
 	workspace := t.TempDir()
 	paths := buildSessionPaths(workspace, "campaign", "session")

internal/artifacts/catalog.go

@@ -216,11 +216,10 @@ func (c *ArtifactCatalog) addEntry(entry CatalogEntry) error {
 }
 
 func runtimeBuiltInArtifactIDs() []string {
-	return []string{
-		ArtifactTranscriptBase,
-		ArtifactTranscriptPolished,
-		ArtifactTranscriptFinal,
-		ArtifactTranscriptFinalTrimmed,
-		ArtifactBoundsSession,
+	ids := make([]string, 0, len(RuntimeTranscriptArtifacts())+1)
+	for _, transcript := range RuntimeTranscriptArtifacts() {
+		ids = append(ids, transcript.SourceID)
 	}
+	ids = append(ids, ArtifactBoundsSession)
+	return ids
 }

internal/artifacts/catalog_test.go

@@ -23,6 +23,26 @@ func TestArtifactCatalogRegisterBuiltInsAndLookup(t *testing.T) {
 	}
 }
 
+func TestArtifactCatalogRegisterBuiltInsIncludesMarkdownSources(t *testing.T) {
+	catalog := NewArtifactCatalog()
+	if err := catalog.RegisterBuiltIns(); err != nil {
+		t.Fatalf("RegisterBuiltIns() error = %v", err)
+	}
+
+	for _, sourceID := range []string{
+		ArtifactTranscriptFinalMarkdown,
+		ArtifactTranscriptFinalTrimmedMarkdown,
+	} {
+		entry, ok := catalog.Lookup(sourceID)
+		if !ok {
+			t.Fatalf("Lookup(%q) ok=false, want true", sourceID)
+		}
+		if !entry.Planned {
+			t.Fatalf("%s planned=false, want true", sourceID)
+		}
+	}
+}
+
 func TestArtifactCatalogRegisterConfiguredArtifactsDefaultsToEnabled(t *testing.T) {
 	catalog := NewArtifactCatalog()
 	if err := catalog.RegisterConfiguredArtifacts(map[string]ConfiguredArtifactDefinition{

internal/artifacts/transcripts_test.go

@@ -31,6 +31,18 @@ func TestRuntimeTranscriptArtifacts(t *testing.T) {
 			ProducerStage:    "trim",
 			OutputKind:       TranscriptOutputKindFinalTrimmed,
 		},
+		{
+			SourceID:         ArtifactTranscriptFinalMarkdown,
+			CanonicalRelPath: TranscriptPathFinalMarkdown,
+			ProducerStage:    "render",
+			OutputKind:       TranscriptOutputKindFinalMarkdown,
+		},
+		{
+			SourceID:         ArtifactTranscriptFinalTrimmedMarkdown,
+			CanonicalRelPath: TranscriptPathFinalTrimmedMarkdown,
+			ProducerStage:    "render",
+			OutputKind:       TranscriptOutputKindFinalTrimmedMarkdown,
+		},
 	}
 
 	got := RuntimeTranscriptArtifacts()
@@ -75,6 +87,18 @@ func TestPlannedTranscriptArtifacts(t *testing.T) {
 			ProducerStage:    "trim",
 			OutputKind:       TranscriptOutputKindFinalTrimmed,
 		},
+		{
+			SourceID:         ArtifactTranscriptFinalMarkdown,
+			CanonicalRelPath: TranscriptPathFinalMarkdown,
+			ProducerStage:    "render",
+			OutputKind:       TranscriptOutputKindFinalMarkdown,
+		},
+		{
+			SourceID:         ArtifactTranscriptFinalTrimmedMarkdown,
+			CanonicalRelPath: TranscriptPathFinalTrimmedMarkdown,
+			ProducerStage:    "render",
+			OutputKind:       TranscriptOutputKindFinalTrimmedMarkdown,
+		},
 	}
 
 	got := PlannedTranscriptArtifacts()
@@ -113,10 +137,14 @@ func TestRuntimeArtifactRegistryUsesTranscriptSpecs(t *testing.T) {
 		if !ok {
 			t.Fatalf("artifactRegistry missing %q", transcript.SourceID)
 		}
+		wantContentKind := contentTranscriptJSON
+		if transcript.SourceID == ArtifactTranscriptFinalMarkdown || transcript.SourceID == ArtifactTranscriptFinalTrimmedMarkdown {
+			wantContentKind = contentText
+		}
 		if spec.CanonicalRelPath != transcript.CanonicalRelPath ||
 			spec.ProducerStage != transcript.ProducerStage ||
 			spec.OutputKind != transcript.OutputKind ||
-			spec.ContentKind != contentTranscriptJSON {
+			spec.ContentKind != wantContentKind {
 			t.Fatalf("artifactRegistry[%q] = %#v, want transcript spec %#v", transcript.SourceID, spec, transcript)
 		}
 	}

internal/config/config.go

@@ -28,6 +28,7 @@ type PipelineConfig struct {
 	Audita       AuditaConfig       `yaml:"audita"`
 	Normalize    *NormalizeConfig   `yaml:"normalize"`
 	Trim         *TrimConfig        `yaml:"trim"`
+	Render       *RenderConfig      `yaml:"render"`
 	Scriptorium  *ScriptoriumConfig `yaml:"scriptorium"`
 	Notification NotificationConfig `yaml:"notification"`
 }
@@ -209,6 +210,16 @@ type TrimSeriatimConfig struct {
 	Report *bool `yaml:"report"`
 }
 
+// RenderConfig configures render-stage output formatting behavior.
+type RenderConfig struct {
+	Enabled           *bool  `yaml:"enabled"`
+	Format            string `yaml:"format"`
+	Title             string `yaml:"title"`
+	IncludeTimestamps *bool  `yaml:"include_timestamps"`
+	IncludeSegmentIDs bool   `yaml:"include_segment_ids"`
+	IncludeMetadata   bool   `yaml:"include_metadata"`
+}
+
 // ScriptoriumConfig configures Scriptorium-backed artifact generation.
 type ScriptoriumConfig struct {
 	Binary      string                               `yaml:"binary"`

internal/config/defaults.go

@@ -40,6 +40,12 @@ const (
 
 	DefaultTrimBoundsTimeout  = "10m"
 	DefaultTrimSeriatimReport = false
+	DefaultRenderEnabled      = true
+	DefaultRenderFormat       = "markdown"
+	DefaultRenderTitle        = ""
+	DefaultRenderTimestamps   = true
+	DefaultRenderSegmentIDs   = false
+	DefaultRenderMetadata     = false
 
 	DefaultNormalizeOutputPath   = artifactmodel.TranscriptPathFinal
 	DefaultNormalizeOutputSchema = "seriatim-intermediate"

internal/config/load.go

@@ -337,6 +337,7 @@ func applyPipelineDefaults(cfg *PipelineConfig) {
 	}
 	applyNormalizeDefaults(cfg.Normalize)
 	applyTrimDefaults(cfg.Trim)
+	applyRenderDefaults(&cfg.Render)
 	applyScriptoriumDefaults(cfg.Scriptorium)
 }
 
@@ -507,6 +508,27 @@ func applyTrimDefaults(cfg *TrimConfig) {
 	}
 }
 
+func applyRenderDefaults(cfg **RenderConfig) {
+	if cfg == nil {
+		return
+	}
+	if *cfg == nil {
+		*cfg = &RenderConfig{}
+	}
+	if (*cfg).Enabled == nil {
+		(*cfg).Enabled = boolPtr(DefaultRenderEnabled)
+	}
+	if strings.TrimSpace((*cfg).Format) == "" {
+		(*cfg).Format = DefaultRenderFormat
+	}
+	if strings.TrimSpace((*cfg).Title) == "" {
+		(*cfg).Title = DefaultRenderTitle
+	}
+	if (*cfg).IncludeTimestamps == nil {
+		(*cfg).IncludeTimestamps = boolPtr(DefaultRenderTimestamps)
+	}
+}
+
 func applyNormalizeDefaults(cfg *NormalizeConfig) {
 	if cfg == nil {
 		return

internal/config/render_test.go

@@ -0,0 +1,128 @@
+package config
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestRenderLoadAndValidate(t *testing.T) {
+	tests := []struct {
+		name            string
+		renderYAML      string
+		wantLoadErr     string
+		wantValidateErr string
+		assert          func(t *testing.T, cfg *Config)
+	}{
+		{
+			name:       "render defaults when omitted",
+			renderYAML: "",
+			assert: func(t *testing.T, cfg *Config) {
+				t.Helper()
+				if cfg.Pipeline.Render == nil {
+					t.Fatal("render config should be present via defaults")
+				}
+				if cfg.Pipeline.Render.Enabled == nil || !*cfg.Pipeline.Render.Enabled {
+					t.Fatalf("render.enabled = %#v, want true", cfg.Pipeline.Render.Enabled)
+				}
+				if cfg.Pipeline.Render.Format != "markdown" {
+					t.Fatalf("render.format = %q, want markdown", cfg.Pipeline.Render.Format)
+				}
+				if cfg.Pipeline.Render.IncludeTimestamps == nil || !*cfg.Pipeline.Render.IncludeTimestamps {
+					t.Fatalf("render.include_timestamps = %#v, want true", cfg.Pipeline.Render.IncludeTimestamps)
+				}
+				if cfg.Pipeline.Render.IncludeSegmentIDs {
+					t.Fatalf("render.include_segment_ids = true, want false")
+				}
+				if cfg.Pipeline.Render.IncludeMetadata {
+					t.Fatalf("render.include_metadata = true, want false")
+				}
+			},
+		},
+		{
+			name: "valid explicit render config",
+			renderYAML: `render:
+  enabled: false
+  format: markdown
+  title: Session Render
+  include_timestamps: false
+  include_segment_ids: true
+  include_metadata: true
+`,
+			assert: func(t *testing.T, cfg *Config) {
+				t.Helper()
+				if cfg.Pipeline.Render == nil {
+					t.Fatal("render config should be present")
+				}
+				if cfg.Pipeline.Render.Enabled == nil || *cfg.Pipeline.Render.Enabled {
+					t.Fatalf("render.enabled = %#v, want false", cfg.Pipeline.Render.Enabled)
+				}
+				if cfg.Pipeline.Render.IncludeTimestamps == nil || *cfg.Pipeline.Render.IncludeTimestamps {
+					t.Fatalf("render.include_timestamps = %#v, want false", cfg.Pipeline.Render.IncludeTimestamps)
+				}
+				if !cfg.Pipeline.Render.IncludeSegmentIDs {
+					t.Fatalf("render.include_segment_ids = false, want true")
+				}
+				if !cfg.Pipeline.Render.IncludeMetadata {
+					t.Fatalf("render.include_metadata = false, want true")
+				}
+			},
+		},
+		{
+			name: "invalid render format fails",
+			renderYAML: `render:
+  format: html
+`,
+			wantValidateErr: "pipeline.render.format must be markdown",
+		},
+		{
+			name: "unknown render field fails strict decoding",
+			renderYAML: `render:
+  format: markdown
+  unknown: true
+`,
+			wantLoadErr: "strict decode failed",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			pipelineYAML := testPipelineBaseYAML
+			if tt.renderYAML != "" {
+				pipelineYAML += "\n" + tt.renderYAML
+			}
+			pipelinePath, sessionPath := writeConfigFiles(t, pipelineYAML, testSessionBaseYAML)
+
+			cfg, err := Load(pipelinePath, sessionPath)
+			if tt.wantLoadErr != "" {
+				if err == nil {
+					t.Fatalf("expected load error containing %q, got nil", tt.wantLoadErr)
+				}
+				if !strings.Contains(err.Error(), tt.wantLoadErr) {
+					t.Fatalf("load error = %q, want to contain %q", err.Error(), tt.wantLoadErr)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("Load() error = %v", err)
+			}
+
+			if tt.assert != nil {
+				tt.assert(t, cfg)
+			}
+
+			err = Validate(cfg)
+			if tt.wantValidateErr != "" {
+				if err == nil {
+					t.Fatalf("expected validation error containing %q, got nil", tt.wantValidateErr)
+				}
+				if !strings.Contains(err.Error(), tt.wantValidateErr) {
+					t.Fatalf("validation error = %q, want to contain %q", err.Error(), tt.wantValidateErr)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("Validate() error = %v", err)
+			}
+		})
+	}
+}

internal/config/validate.go

@@ -88,6 +88,9 @@ func validatePipeline(cfg *PipelineConfig) error {
 	if err := validateTrim(cfg.Trim); err != nil {
 		return err
 	}
+	if err := validateRender(cfg.Render); err != nil {
+		return err
+	}
 	if err := validateScriptorium(cfg.Scriptorium); err != nil {
 		return err
 	}
@@ -299,6 +302,26 @@ func validateTrim(cfg *TrimConfig) error {
 	return nil
 }
 
+func validateRender(cfg *RenderConfig) error {
+	if cfg == nil {
+		return nil
+	}
+	if cfg.Enabled == nil {
+		return fmt.Errorf("pipeline.render.enabled must be set (defaults should populate this)")
+	}
+	if cfg.IncludeTimestamps == nil {
+		return fmt.Errorf("pipeline.render.include_timestamps must be set (defaults should populate this)")
+	}
+	format := strings.TrimSpace(cfg.Format)
+	if format != "markdown" {
+		return fmt.Errorf("pipeline.render.format must be markdown")
+	}
+	if cfg.Title != "" && strings.TrimSpace(cfg.Title) == "" {
+		return fmt.Errorf("pipeline.render.title must be non-empty when provided")
+	}
+	return nil
+}
+
 func validateWhisperX(cfg WhisperXConfig) error {
 	if strings.TrimSpace(cfg.TranscribeURL) == "" {
 		return fmt.Errorf("pipeline.whisperx.transcribe_url is required")