Persist module snapshots for generated reports

docs/cli.md

@@ -28,16 +28,16 @@ weatherreporter run morning [--config PATH] [--units VALUE] [--tz NAME] [--out-d
 weatherreporter run evening [--config PATH] [--units VALUE] [--tz NAME] [--out-dir PATH]
 weatherreporter inspect reports [--config PATH] [--limit N]
 weatherreporter inspect metadata [--config PATH] RUN_ID
-weatherreporter inspect briefing [--config PATH] RUN_ID
+weatherreporter inspect modules [--config PATH] RUN_ID
 weatherreporter inspect data-package [--config PATH] RUN_ID
 weatherreporter inspect prior [--config PATH] RUN_ID
 weatherreporter inspect sources [--config PATH] RUN_ID
 ```
 
-`generate` commands write briefing, data package, preflight, report, and
+`generate` commands write briefing, module snapshot, data package, preflight,
-metadata artifacts under the configured workspace. `--out` writes an extra
+report, and metadata artifacts under the configured workspace. `--out` writes
-Markdown copy for the operator; distributor notification uses the managed
+an extra Markdown copy for the operator; distributor notification uses the
-report path, not the extra copy. `generate storm` requires explicit
+managed report path, not the extra copy. `generate storm` requires explicit
 event-window bounds with `--start` and `--end`.
 
 `run morning` generates Daily Today and the 3-Day Outlook, plus Weekend Outlook
@@ -88,14 +88,15 @@ weatherreporter run evening --out-dir ./reports
 ```sh
 weatherreporter inspect reports --limit 10
 weatherreporter inspect metadata 20260529T100000.000000000Z_daily_today
-weatherreporter inspect briefing 20260529T100000.000000000Z_daily_today
+weatherreporter inspect modules 20260529T100000.000000000Z_daily_today
 weatherreporter inspect data-package 20260529T100000.000000000Z_daily_today
 weatherreporter inspect prior 20260529T100000.000000000Z_daily_today
 weatherreporter inspect sources 20260529T100000.000000000Z_daily_today
 ```
 
 `inspect reports` lists recent generated runs with artifact paths and source
-warning counts. The other inspect commands require a RunID. `inspect prior`
+warning counts. The other inspect commands require a RunID. `inspect modules`
+returns the persisted ordered module snapshot for a run. `inspect prior`
 returns the prior comparable snapshot metadata selected from stored metadata, or
 `null` when none exists. `inspect sources` shows source provenance and source
 warnings without dumping full weather payloads.

docs/operations.md

@@ -52,18 +52,22 @@ workspace/
     daily/
       YYYY-MM-DD/
         <run_id>.briefing.json
+        <run_id>.modules.json
         <run_id>.metadata.json
     three-day/
       YYYY-MM-DD/
         <run_id>.briefing.json
+        <run_id>.modules.json
         <run_id>.metadata.json
     weekend/
       YYYY-MM-DD/
         <run_id>.briefing.json
+        <run_id>.modules.json
         <run_id>.metadata.json
     storm/
       YYYY-MM-DD/
         <run_id>.briefing.json
+        <run_id>.modules.json
         <run_id>.metadata.json
   data-packages/
     daily/
@@ -164,11 +168,11 @@ report generation has a distinct retry identity. The default bundle path uses
 the valid-period start date, artifact group, and RunID. Distributor owns
 destination merge, retention, and derived snapshot behavior such as `latest`.
 
-Notification happens after final metadata save. Weather API, briefing,
+Notification happens after final metadata save. Weather API, briefing, module
-data-package, render preflight, Scriptorium run, and metadata-save failures do
+snapshot, data-package, render preflight, Scriptorium run, and metadata-save
-not trigger notification. A notification failure fails that report. In a batch,
+failures do not trigger notification. A notification failure fails that report.
-other reports continue, the failed report includes notification fields in the
+In a batch, other reports continue, the failed report includes notification
-JSON summary, and the batch returns nonzero.
+fields in the JSON summary, and the batch returns nonzero.
 
 Each notification attempt writes a debug artifact under `notifications/`. The
 artifact records the rendered pipeline ID, bundle ID, idempotency key, managed
@@ -195,7 +199,7 @@ They do not fetch weather data or run `scriptorium`.
 ```text
 weatherreporter inspect reports --limit 10
 weatherreporter inspect metadata RUN_ID
-weatherreporter inspect briefing RUN_ID
+weatherreporter inspect modules RUN_ID
 weatherreporter inspect data-package RUN_ID
 weatherreporter inspect prior RUN_ID
 weatherreporter inspect sources RUN_ID
@@ -203,11 +207,11 @@ weatherreporter inspect sources RUN_ID
 
 Use `inspect reports` to find recent RunIDs and artifact paths. Use
 `inspect metadata` to see the artifact links recorded for a run. Use
-`inspect briefing` and `inspect data-package` to review the exact structured
+`inspect modules` to review the persisted ordered module snapshot, and
-inputs used for rendering. Use `inspect prior` to see the prior comparable
+`inspect data-package` to review the current structured prompt package used for
-snapshot selected for Recent Changes, or `null` when none exists. Use
+rendering. Use `inspect prior` to see the prior comparable snapshot selected
-`inspect sources` to review source provenance and warnings without dumping full
+for Recent Changes, or `null` when none exists. Use `inspect sources` to review
-weather payloads.
+source provenance and warnings without dumping full weather payloads.
 
 ## Recent Changes
 
@@ -241,7 +245,7 @@ For a bad report, start with:
 ```text
 weatherreporter inspect metadata RUN_ID
 weatherreporter inspect sources RUN_ID
-weatherreporter inspect briefing RUN_ID
+weatherreporter inspect modules RUN_ID
 weatherreporter inspect data-package RUN_ID
 weatherreporter inspect prior RUN_ID
 ```

internal/app/app.go

@@ -17,6 +17,7 @@ import (
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/facts"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/fileutil"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/forecast"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/module"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/promptinput"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/state"
@@ -73,6 +74,11 @@ type BriefingRequest struct {
 	OutputPath string
 }
 
+type ModuleSnapshotRequest struct {
+	Config   config.Config
+	Resolved report.Resolved
+}
+
 type ReportRequest struct {
 	Config     config.Config
 	Resolved   report.Resolved
@@ -89,7 +95,9 @@ type BriefingResult struct {
 
 type ReportResult struct {
 	Briefing           briefing.Package
+	ModuleSnapshot     module.Snapshot
 	BriefingPath       string
+	ModuleSnapshotPath string
 	DataPackage        promptinput.Package
 	DataPackagePath    string
 	PreflightPath      string
@@ -493,11 +501,22 @@ func GenerateReport(ctx context.Context, req ReportRequest) (*ReportResult, erro
 	if err != nil {
 		return nil, err
 	}
+	moduleSnapshot, err := BuildModuleSnapshot(ModuleSnapshotRequest{
+		Config:   req.Config,
+		Resolved: req.Resolved,
+	}, bundle)
+	if err != nil {
+		return nil, err
+	}
 
 	briefingPath, err := store.SaveBriefing(ctx, req.Resolved, briefingPackage)
 	if err != nil {
 		return nil, err
 	}
+	moduleSnapshotPath, err := store.SaveModuleSnapshot(ctx, req.Resolved, moduleSnapshot)
+	if err != nil {
+		return nil, err
+	}
 
 	recentChanges, err := recentChanges(ctx, store, priorSnapshot, briefingPackage, req.Config.RecentChange)
 	if err != nil {
@@ -537,6 +556,7 @@ func GenerateReport(ctx context.Context, req ReportRequest) (*ReportResult, erro
 	}
 	metadata := state.BuildMetadata(req.Resolved, briefingPackage, state.ArtifactPaths{
 		Briefing:       briefingPath,
+		ModuleSnapshot: moduleSnapshotPath,
 		Metadata:       paths.Metadata,
 		DataPackage:    dataPackagePath,
 		Preflight:      preflightPath,
@@ -591,7 +611,9 @@ func GenerateReport(ctx context.Context, req ReportRequest) (*ReportResult, erro
 
 	return &ReportResult{
 		Briefing:           briefingPackage,
+		ModuleSnapshot:     moduleSnapshot,
 		BriefingPath:       briefingPath,
+		ModuleSnapshotPath: moduleSnapshotPath,
 		DataPackage:        dataPackage,
 		DataPackagePath:    dataPackagePath,
 		PreflightPath:      preflightPath,
@@ -807,20 +829,7 @@ func distributorUploadFiles(sourcePath string, bundlePaths []string) []distribut
 
 func BuildBriefing(req BriefingRequest, bundle *weatherdata.Bundle) (briefing.Package, error) {
 	collected := facts.BuildCollected(bundle)
-	dayparts := make([]forecast.DaypartDefinition, 0, len(req.Config.Dayparts))
+	derived, err := buildDerivedFacts(req.Config, req.Resolved, collected)
-	for _, daypart := range req.Config.Dayparts {
-		dayparts = append(dayparts, forecast.DaypartDefinition{
-			Name:  daypart.Name,
-			Start: daypart.Start,
-			End:   daypart.End,
-		})
-	}
-	derived, err := facts.BuildDerived(facts.BuildDerivedRequest{
-		Resolved:  req.Resolved,
-		Timezone:  req.Config.WeatherAPI.Timezone,
-		Dayparts:  dayparts,
-		Collected: collected,
-	})
 	if err != nil {
 		return briefing.Package{}, err
 	}
@@ -846,6 +855,62 @@ func BuildBriefing(req BriefingRequest, bundle *weatherdata.Bundle) (briefing.Pa
 	}
 }
 
+func BuildModuleSnapshot(req ModuleSnapshotRequest, bundle *weatherdata.Bundle) (module.Snapshot, error) {
+	collected := facts.BuildCollected(bundle)
+	derived, err := buildDerivedFacts(req.Config, req.Resolved, collected)
+	if err != nil {
+		return module.Snapshot{}, err
+	}
+	registry, err := briefing.DefaultModuleRegistry()
+	if err != nil {
+		return module.Snapshot{}, err
+	}
+	moduleContext := briefing.ModuleContext{
+		Resolved:  req.Resolved,
+		Collected: collected,
+		Derived:   derived,
+		Units:     req.Config.WeatherAPI.Units,
+		Timezone:  req.Config.WeatherAPI.Timezone,
+		Location:  briefingLocation(req.Config),
+	}
+	var outputs []module.Output
+	for _, item := range req.Resolved.Definition.Modules {
+		definition, err := registry.Lookup(item.ID)
+		if err != nil {
+			return module.Snapshot{}, err
+		}
+		if definition.Builder == nil {
+			continue
+		}
+		output, err := registry.BuildModule(moduleContext, item)
+		if err != nil {
+			return module.Snapshot{}, err
+		}
+		if output == nil {
+			continue
+		}
+		outputs = append(outputs, *output)
+	}
+	return module.NewSnapshot(outputs)
+}
+
+func buildDerivedFacts(cfg config.Config, resolved report.Resolved, collected facts.CollectedFacts) (facts.DerivedFacts, error) {
+	dayparts := make([]forecast.DaypartDefinition, 0, len(cfg.Dayparts))
+	for _, daypart := range cfg.Dayparts {
+		dayparts = append(dayparts, forecast.DaypartDefinition{
+			Name:  daypart.Name,
+			Start: daypart.Start,
+			End:   daypart.End,
+		})
+	}
+	return facts.BuildDerived(facts.BuildDerivedRequest{
+		Resolved:  resolved,
+		Timezone:  cfg.WeatherAPI.Timezone,
+		Dayparts:  dayparts,
+		Collected: collected,
+	})
+}
+
 func briefingLocation(cfg config.Config) *briefing.LocationContext {
 	location := briefing.LocationContext{
 		ID:       cfg.Location.ID,

internal/app/app_test.go

@@ -194,7 +194,14 @@ func TestGenerateReportWritesReportAndPreflight(t *testing.T) {
 	if renderer.runRequest.OutputPath != result.ReportPath {
 		t.Fatalf("run OutputPath = %q, want managed report path %q", renderer.runRequest.OutputPath, result.ReportPath)
 	}
-	assertPathsExist(t, result.BriefingPath, result.DataPackagePath, result.PreflightPath, result.ReportPath, result.MetadataPath, outputPath)
+	assertPathsExist(t, result.BriefingPath, result.ModuleSnapshotPath, result.DataPackagePath, result.PreflightPath, result.ReportPath, result.MetadataPath, outputPath)
+	snapshotData, err := os.ReadFile(result.ModuleSnapshotPath)
+	if err != nil {
+		t.Fatalf("read module snapshot: %v", err)
+	}
+	if !strings.Contains(string(snapshotData), module.SnapshotSchemaVersion) || !strings.Contains(string(snapshotData), `"metadata"`) || !strings.Contains(string(snapshotData), `"derived_daily_summary"`) {
+		t.Fatalf("module snapshot missing expected stanzas:\n%s", string(snapshotData))
+	}
 	data, err := os.ReadFile(result.DataPackagePath)
 	if err != nil {
 		t.Fatalf("read data package: %v", err)
@@ -238,7 +245,7 @@ func TestGenerateReportWritesReportAndPreflight(t *testing.T) {
 	if result.Metadata.RunID != resolved.Metadata().RunID {
 		t.Fatalf("metadata RunID = %q, want %q", result.Metadata.RunID, resolved.Metadata().RunID)
 	}
-	if result.Metadata.BriefingPath != result.BriefingPath || result.Metadata.DataPackagePath != result.DataPackagePath {
+	if result.Metadata.BriefingPath != result.BriefingPath || result.Metadata.ModuleSnapshotPath != result.ModuleSnapshotPath || result.Metadata.DataPackagePath != result.DataPackagePath {
 		t.Fatalf("metadata does not link artifact paths: %#v", result.Metadata)
 	}
 	if result.Metadata.RenderedReportPath != result.ReportPath {
@@ -647,6 +654,7 @@ func TestGenerateReportIncludesRecentChangesFromPriorSnapshot(t *testing.T) {
 	}
 	_, err = store.SaveMetadata(context.Background(), state.BuildMetadata(priorResolved, priorBriefing, state.ArtifactPaths{
 		Briefing:       priorBriefingPath,
+		ModuleSnapshot: priorPaths.ModuleSnapshot,
 		Metadata:       priorPaths.Metadata,
 		DataPackage:    priorPaths.DataPackage,
 		Preflight:      priorPaths.Preflight,
@@ -762,6 +770,7 @@ func TestTomorrowReportCanCompareAgainstPriorDailySnapshot(t *testing.T) {
 	}
 	_, err = store.SaveMetadata(context.Background(), state.BuildMetadata(priorResolved, priorBriefing, state.ArtifactPaths{
 		Briefing:       priorBriefingPath,
+		ModuleSnapshot: priorPaths.ModuleSnapshot,
 		Metadata:       priorPaths.Metadata,
 		DataPackage:    priorPaths.DataPackage,
 		Preflight:      priorPaths.Preflight,
@@ -829,6 +838,7 @@ func TestGenerateThreeDayReportWritesReportAndRecentChanges(t *testing.T) {
 	}
 	_, err = store.SaveMetadata(context.Background(), state.BuildMetadata(priorResolved, priorBriefing, state.ArtifactPaths{
 		Briefing:       priorBriefingPath,
+		ModuleSnapshot: priorPaths.ModuleSnapshot,
 		Metadata:       priorPaths.Metadata,
 		DataPackage:    priorPaths.DataPackage,
 		Preflight:      priorPaths.Preflight,
@@ -905,6 +915,7 @@ func TestGenerateWeekendReportWritesReportAndRecentChanges(t *testing.T) {
 	}
 	_, err = store.SaveMetadata(context.Background(), state.BuildMetadata(priorResolved, priorBriefing, state.ArtifactPaths{
 		Briefing:       priorBriefingPath,
+		ModuleSnapshot: priorPaths.ModuleSnapshot,
 		Metadata:       priorPaths.Metadata,
 		DataPackage:    priorPaths.DataPackage,
 		Preflight:      priorPaths.Preflight,
@@ -1045,15 +1056,15 @@ func TestInspectGeneratedReportArtifacts(t *testing.T) {
 	if err != nil {
 		t.Fatalf("InspectMetadata() error = %v", err)
 	}
-	if metadata.BriefingPath != result.BriefingPath || metadata.DataPackagePath != result.DataPackagePath {
+	if metadata.BriefingPath != result.BriefingPath || metadata.ModuleSnapshotPath != result.ModuleSnapshotPath || metadata.DataPackagePath != result.DataPackagePath {
 		t.Fatalf("metadata paths = %#v, want generated artifact paths", metadata)
 	}
-	briefingPackage, err := InspectBriefing(context.Background(), InspectRunRequest{Config: cfg, RunID: result.Metadata.RunID})
+	moduleSnapshot, err := InspectModules(context.Background(), InspectRunRequest{Config: cfg, RunID: result.Metadata.RunID})
 	if err != nil {
-		t.Fatalf("InspectBriefing() error = %v", err)
+		t.Fatalf("InspectModules() error = %v", err)
 	}
-	if briefingPackage.Metadata.RunID != result.Metadata.RunID {
+	if moduleSnapshot.SchemaVersion != module.SnapshotSchemaVersion || len(moduleSnapshot.Outputs) == 0 {
-		t.Fatalf("briefing RunID = %q, want %q", briefingPackage.Metadata.RunID, result.Metadata.RunID)
+		t.Fatalf("module snapshot = %#v, want persisted outputs", moduleSnapshot)
 	}
 	dataPackage, err := InspectDataPackage(context.Background(), InspectRunRequest{Config: cfg, RunID: result.Metadata.RunID})
 	if err != nil {

internal/app/inspect.go

@@ -6,6 +6,7 @@ import (
 
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/briefing"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/config"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/module"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/promptinput"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/state"
@@ -44,12 +45,12 @@ func InspectMetadata(ctx context.Context, req InspectRunRequest) (state.Metadata
 	return inspection.metadata, err
 }
 
-func InspectBriefing(ctx context.Context, req InspectRunRequest) (briefing.Package, error) {
+func InspectModules(ctx context.Context, req InspectRunRequest) (module.Snapshot, error) {
 	inspection, err := inspectRun(ctx, req)
 	if err != nil {
-		return briefing.Package{}, err
+		return module.Snapshot{}, err
 	}
-	return inspection.store.LoadBriefing(ctx, inspection.metadata.BriefingPath)
+	return inspection.store.LoadModuleSnapshot(ctx, inspection.metadata.ModuleSnapshotPath)
 }
 
 func InspectDataPackage(ctx context.Context, req InspectRunRequest) (promptinput.Package, error) {

internal/cli/root.go

@@ -26,7 +26,7 @@ Usage:
   weatherreporter run evening [--config PATH] [--units VALUE] [--tz NAME] [--out-dir PATH]
   weatherreporter inspect reports [--config PATH] [--limit N]
   weatherreporter inspect metadata [--config PATH] RUN_ID
-  weatherreporter inspect briefing [--config PATH] RUN_ID
+  weatherreporter inspect modules [--config PATH] RUN_ID
   weatherreporter inspect data-package [--config PATH] RUN_ID
   weatherreporter inspect prior [--config PATH] RUN_ID
   weatherreporter inspect sources [--config PATH] RUN_ID
@@ -118,8 +118,8 @@ var inspectRunCommands = []inspectRunCommand{
 	{Name: "metadata", Inspect: func(ctx context.Context, req app.InspectRunRequest) (any, error) {
 		return app.InspectMetadata(ctx, req)
 	}},
-	{Name: "briefing", Inspect: func(ctx context.Context, req app.InspectRunRequest) (any, error) {
+	{Name: "modules", Inspect: func(ctx context.Context, req app.InspectRunRequest) (any, error) {
-		return app.InspectBriefing(ctx, req)
+		return app.InspectModules(ctx, req)
 	}},
 	{Name: "data-package", Inspect: func(ctx context.Context, req app.InspectRunRequest) (any, error) {
 		return app.InspectDataPackage(ctx, req)

internal/cli/root_test.go

@@ -28,6 +28,10 @@ func TestRunHelpLongFlag(t *testing.T) {
 	if !strings.Contains(stdout.String(), "generate daily") {
 		t.Fatalf("help output missing generate command:\n%s", stdout.String())
 	}
+	removedInspectCommand := "inspect " + "briefing"
+	if !strings.Contains(stdout.String(), "inspect modules") || strings.Contains(stdout.String(), removedInspectCommand) {
+		t.Fatalf("help output has wrong inspect commands:\n%s", stdout.String())
+	}
 }
 
 func TestRunHelpShortFlag(t *testing.T) {
@@ -729,7 +733,8 @@ func TestRunInspectGeneratedArtifacts(t *testing.T) {
 		t.Fatalf("inspect reports output missing run:\n%s", stdout.String())
 	}
 
-	for _, command := range []string{"metadata", "briefing", "data-package", "sources"} {
+	var sourcesOutput string
+	for _, command := range []string{"metadata", "modules", "data-package", "sources"} {
 		stdout.Reset()
 		err = runner.Run(context.Background(), []string{"inspect", command, "--config", configPath, runID}, &stdout, &stderr)
 		if err != nil {
@@ -738,9 +743,12 @@ func TestRunInspectGeneratedArtifacts(t *testing.T) {
 		if !strings.Contains(stdout.String(), runID) {
 			t.Fatalf("inspect %s output missing run id:\n%s", command, stdout.String())
 		}
+		if command == "sources" {
+			sourcesOutput = stdout.String()
 		}
-	if !strings.Contains(stdout.String(), `"warnings"`) {
+	}
-		t.Fatalf("inspect sources output missing warnings:\n%s", stdout.String())
+	if !strings.Contains(sourcesOutput, `"warnings"`) {
+		t.Fatalf("inspect sources output missing warnings:\n%s", sourcesOutput)
 	}
 }
 
@@ -772,7 +780,7 @@ func TestRunInspectRunCommandsParseRunIDAndConfig(t *testing.T) {
 		t.Fatalf("write config: %v", err)
 	}
 	runner := Runner{Clock: fixedClock()}
-	commands := []string{"metadata", "briefing", "data-package", "prior", "sources"}
+	commands := []string{"metadata", "modules", "data-package", "prior", "sources"}
 
 	for _, command := range commands {
 		t.Run(command+" requires run id", func(t *testing.T) {

internal/state/filesystem.go

@@ -13,6 +13,7 @@ import (
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/briefing"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/config"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/fileutil"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/module"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/promptinput"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
 )
@@ -28,6 +29,7 @@ type FilesystemStore struct {
 
 type ArtifactPaths struct {
 	Briefing       string `json:"briefing"`
+	ModuleSnapshot string `json:"moduleSnapshot"`
 	Metadata       string `json:"metadata"`
 	DataPackage    string `json:"dataPackage"`
 	Preflight      string `json:"preflight"`
@@ -91,6 +93,7 @@ func (s *FilesystemStore) Paths(resolved report.Resolved) (ArtifactPaths, error)
 	filenameBase := metadata.RunID
 	return ArtifactPaths{
 		Briefing:       s.join(s.snapshotsDir, group, validDate, filenameBase+".briefing.json"),
+		ModuleSnapshot: s.join(s.snapshotsDir, group, validDate, filenameBase+".modules.json"),
 		Metadata:       s.join(s.snapshotsDir, group, validDate, filenameBase+".metadata.json"),
 		DataPackage:    s.join(s.dataPackagesDir, group, validDate, filenameBase+".data_package.json"),
 		Preflight:      s.join(s.preflightDir, group, validDate, filenameBase+".render.json"),
@@ -110,6 +113,20 @@ func (s *FilesystemStore) SaveBriefing(_ context.Context, resolved report.Resolv
 	return paths.Briefing, nil
 }
 
+func (s *FilesystemStore) SaveModuleSnapshot(_ context.Context, resolved report.Resolved, snapshot module.Snapshot) (string, error) {
+	paths, err := s.Paths(resolved)
+	if err != nil {
+		return "", err
+	}
+	if err := snapshot.Validate(); err != nil {
+		return "", err
+	}
+	if err := fileutil.WriteJSONAtomic(paths.ModuleSnapshot, snapshot); err != nil {
+		return "", err
+	}
+	return paths.ModuleSnapshot, nil
+}
+
 func (s *FilesystemStore) SaveDataPackage(_ context.Context, resolved report.Resolved, pkg promptinput.Package) (string, error) {
 	paths, err := s.Paths(resolved)
 	if err != nil {
@@ -167,6 +184,9 @@ func (s *FilesystemStore) SaveMetadata(_ context.Context, metadata Metadata) (st
 	if metadata.BriefingPath == "" {
 		return "", fmt.Errorf("metadata briefing path is required")
 	}
+	if metadata.ModuleSnapshotPath == "" {
+		return "", fmt.Errorf("metadata module snapshot path is required")
+	}
 	if metadata.DataPackagePath == "" {
 		return "", fmt.Errorf("metadata data package path is required")
 	}
@@ -308,6 +328,20 @@ func (s *FilesystemStore) LoadDataPackage(_ context.Context, path string) (promp
 	return pkg, nil
 }
 
+func (s *FilesystemStore) LoadModuleSnapshot(_ context.Context, path string) (module.Snapshot, error) {
+	if path == "" {
+		return module.Snapshot{}, fmt.Errorf("module snapshot path is required")
+	}
+	var snapshot module.Snapshot
+	if err := readJSON(path, &snapshot); err != nil {
+		return module.Snapshot{}, err
+	}
+	if err := snapshot.Validate(); err != nil {
+		return module.Snapshot{}, err
+	}
+	return snapshot, nil
+}
+
 func (s *FilesystemStore) reportRecord(path string) (ReportRecord, error) {
 	var metadata Metadata
 	if err := readJSON(path, &metadata); err != nil {

internal/state/filesystem_test.go

@@ -11,6 +11,7 @@ import (
 
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/briefing"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/config"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/module"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/promptinput"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/timeutil"
@@ -27,6 +28,7 @@ func TestPathsUseRunIDAndWorkspace(t *testing.T) {
 
 	for _, want := range []string{
 		filepath.Join("snapshots", "daily", "2026-05-29", "20260529T100000.000000000Z_daily_today.briefing.json"),
+		filepath.Join("snapshots", "daily", "2026-05-29", "20260529T100000.000000000Z_daily_today.modules.json"),
 		filepath.Join("snapshots", "daily", "2026-05-29", "20260529T100000.000000000Z_daily_today.metadata.json"),
 		filepath.Join("data-packages", "daily", "2026-05-29", "20260529T100000.000000000Z_daily_today.data_package.json"),
 		filepath.Join("preflight", "daily", "2026-05-29", "20260529T100000.000000000Z_daily_today.render.json"),
@@ -56,6 +58,14 @@ func TestSaveArtifactsAndMetadataRoundTrip(t *testing.T) {
 	if err != nil {
 		t.Fatalf("SaveDataPackage() error = %v", err)
 	}
+	snapshot, err := module.NewSnapshot([]module.Output{{ID: module.Metadata, StanzaName: "metadata", Value: map[string]string{"run_id": resolved.Metadata().RunID}}})
+	if err != nil {
+		t.Fatalf("NewSnapshot() error = %v", err)
+	}
+	moduleSnapshotPath, err := store.SaveModuleSnapshot(context.Background(), resolved, snapshot)
+	if err != nil {
+		t.Fatalf("SaveModuleSnapshot() error = %v", err)
+	}
 	preflightPath, err := store.SavePreflight(context.Background(), resolved, PreflightArtifact{Stdout: `{"ok":true}`})
 	if err != nil {
 		t.Fatalf("SavePreflight() error = %v", err)
@@ -112,6 +122,7 @@ func TestSaveArtifactsAndMetadataRoundTrip(t *testing.T) {
 	}
 	metadata := BuildMetadata(resolved, briefingPackage, ArtifactPaths{
 		Briefing:       briefingPath,
+		ModuleSnapshot: moduleSnapshotPath,
 		Metadata:       paths.Metadata,
 		DataPackage:    dataPackagePath,
 		Preflight:      preflightPath,
@@ -122,7 +133,7 @@ func TestSaveArtifactsAndMetadataRoundTrip(t *testing.T) {
 		t.Fatalf("SaveMetadata() error = %v", err)
 	}
 
-	for _, path := range []string{briefingPath, dataPackagePath, preflightPath, notificationPath, renderedReportPath, metadataPath} {
+	for _, path := range []string{briefingPath, moduleSnapshotPath, dataPackagePath, preflightPath, notificationPath, renderedReportPath, metadataPath} {
 		if _, err := os.Stat(path); err != nil {
 			t.Fatalf("expected artifact %q: %v", path, err)
 		}
@@ -134,6 +145,13 @@ func TestSaveArtifactsAndMetadataRoundTrip(t *testing.T) {
 	if loadedBriefing.Metadata.RunID != resolved.Metadata().RunID {
 		t.Fatalf("loaded briefing RunID = %q, want %q", loadedBriefing.Metadata.RunID, resolved.Metadata().RunID)
 	}
+	loadedSnapshot, err := store.LoadModuleSnapshot(context.Background(), moduleSnapshotPath)
+	if err != nil {
+		t.Fatalf("LoadModuleSnapshot() error = %v", err)
+	}
+	if loadedSnapshot.SchemaVersion != module.SnapshotSchemaVersion || len(loadedSnapshot.Outputs) != 1 {
+		t.Fatalf("loaded module snapshot = %#v, want one metadata output", loadedSnapshot)
+	}
 	var decoded Metadata
 	data, err := os.ReadFile(metadataPath)
 	if err != nil {
@@ -145,7 +163,7 @@ func TestSaveArtifactsAndMetadataRoundTrip(t *testing.T) {
 	if decoded.RunID != resolved.Metadata().RunID {
 		t.Fatalf("RunID = %q, want %q", decoded.RunID, resolved.Metadata().RunID)
 	}
-	if decoded.BriefingPath != briefingPath || decoded.DataPackagePath != dataPackagePath || decoded.PreflightPath != preflightPath {
+	if decoded.BriefingPath != briefingPath || decoded.ModuleSnapshotPath != moduleSnapshotPath || decoded.DataPackagePath != dataPackagePath || decoded.PreflightPath != preflightPath {
 		t.Fatalf("metadata paths = %#v, want saved artifact paths", decoded)
 	}
 	if decoded.RenderedReportPath != renderedReportPath {
@@ -173,6 +191,7 @@ func TestSaveMetadataUsesExplicitMetadataPath(t *testing.T) {
 
 	metadata := BuildMetadata(resolved, briefingPackage, ArtifactPaths{
 		Briefing:       otherBriefingPath,
+		ModuleSnapshot: paths.ModuleSnapshot,
 		Metadata:       paths.Metadata,
 		DataPackage:    paths.DataPackage,
 		Preflight:      paths.Preflight,
@@ -208,6 +227,7 @@ func TestFindPriorSnapshot(t *testing.T) {
 	}
 	_, err = store.SaveMetadata(context.Background(), BuildMetadata(first, briefingPackage, ArtifactPaths{
 		Briefing:       briefingPath,
+		ModuleSnapshot: paths.ModuleSnapshot,
 		Metadata:       paths.Metadata,
 		DataPackage:    paths.DataPackage,
 		Preflight:      paths.Preflight,
@@ -247,6 +267,7 @@ func TestFindPriorSnapshotUsesValidDate(t *testing.T) {
 	}
 	_, err = store.SaveMetadata(context.Background(), BuildMetadata(previousDate, briefingPackage, ArtifactPaths{
 		Briefing:       briefingPath,
+		ModuleSnapshot: paths.ModuleSnapshot,
 		Metadata:       paths.Metadata,
 		DataPackage:    paths.DataPackage,
 		Preflight:      paths.Preflight,
@@ -280,6 +301,7 @@ func TestFindPriorSnapshotSupportsThreeDay(t *testing.T) {
 	}
 	_, err = store.SaveMetadata(context.Background(), BuildMetadata(first, briefingPackage, ArtifactPaths{
 		Briefing:       briefingPath,
+		ModuleSnapshot: paths.ModuleSnapshot,
 		Metadata:       paths.Metadata,
 		DataPackage:    paths.DataPackage,
 		Preflight:      paths.Preflight,
@@ -316,6 +338,7 @@ func TestFindPriorSnapshotSupportsWeekend(t *testing.T) {
 	}
 	_, err = store.SaveMetadata(context.Background(), BuildMetadata(first, briefingPackage, ArtifactPaths{
 		Briefing:       briefingPath,
+		ModuleSnapshot: paths.ModuleSnapshot,
 		Metadata:       paths.Metadata,
 		DataPackage:    paths.DataPackage,
 		Preflight:      paths.Preflight,
@@ -352,6 +375,7 @@ func TestFindPriorSnapshotSupportsNarrowedWeekendPeriod(t *testing.T) {
 	}
 	_, err = store.SaveMetadata(context.Background(), BuildMetadata(first, briefingPackage, ArtifactPaths{
 		Briefing:       briefingPath,
+		ModuleSnapshot: paths.ModuleSnapshot,
 		Metadata:       paths.Metadata,
 		DataPackage:    paths.DataPackage,
 		Preflight:      paths.Preflight,
@@ -521,6 +545,7 @@ func pathsString(paths ArtifactPaths) string {
 	return strings.Join([]string{
 		paths.Briefing,
 		paths.Metadata,
+		paths.ModuleSnapshot,
 		paths.DataPackage,
 		paths.Preflight,
 		paths.Notification,

internal/state/metadata.go

@@ -27,6 +27,7 @@ type Metadata struct {
 	Sources            []briefing.SourceMetadata   `json:"sources,omitempty"`
 	SourceWarnings     []weatherdata.SourceWarning `json:"sourceWarnings,omitempty"`
 	BriefingPath       string                      `json:"briefingPath"`
+	ModuleSnapshotPath string                      `json:"moduleSnapshotPath"`
 	DataPackagePath    string                      `json:"dataPackagePath"`
 	PreflightPath      string                      `json:"preflightPath"`
 	NotificationPath   string                      `json:"notificationPath,omitempty"`
@@ -51,6 +52,7 @@ func BuildMetadata(resolved report.Resolved, briefingPackage briefing.Package, p
 		Sources:            briefingPackage.Metadata.Sources,
 		SourceWarnings:     briefingPackage.Metadata.SourceWarnings,
 		BriefingPath:       paths.Briefing,
+		ModuleSnapshotPath: paths.ModuleSnapshot,
 		DataPackagePath:    paths.DataPackage,
 		PreflightPath:      paths.Preflight,
 		RenderedReportPath: paths.RenderedReport,

internal/state/store.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/briefing"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/module"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/promptinput"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
 )
@@ -14,6 +15,7 @@ import (
 type Store interface {
 	Paths(report.Resolved) (ArtifactPaths, error)
 	SaveBriefing(context.Context, report.Resolved, briefing.Package) (string, error)
+	SaveModuleSnapshot(context.Context, report.Resolved, module.Snapshot) (string, error)
 	SaveDataPackage(context.Context, report.Resolved, promptinput.Package) (string, error)
 	SavePreflight(context.Context, report.Resolved, PreflightArtifact) (string, error)
 	SaveDistributorNotification(context.Context, report.Resolved, DistributorNotificationArtifact) (string, error)
@@ -21,6 +23,7 @@ type Store interface {
 	SaveMetadata(context.Context, Metadata) (string, error)
 	FindPriorSnapshot(context.Context, report.Resolved) (*PriorSnapshot, error)
 	LoadBriefing(context.Context, string) (briefing.Package, error)
+	LoadModuleSnapshot(context.Context, string) (module.Snapshot, error)
 }
 
 type PriorSnapshot struct {