Document curated data package exports

docs/internal/module.md

@@ -5,9 +5,9 @@ This document describes the module contract in `internal/module`.
 ## Purpose
 
 `internal/module` defines the shared identifiers and data envelopes used for
-prompt-facing modules. Report definitions use module IDs for composition,
+report modules. Report definitions use module IDs for composition, module
-module builders produce outputs with stanza names, prompt input packages consume
+builders produce rich outputs with stanza names, prompt input packages consume
-snapshots, and Recent Changes compares snapshot stanzas.
+runtime prompt export values, and Recent Changes compares snapshot stanzas.
 
 ## Inputs And Outputs
 
@@ -23,8 +23,38 @@ Outputs:
 - typed option structs for registered modules
 - `module.Snapshot` with schema version `weatherreporter.modules.v1`
 - ordered snapshot outputs with module ID, stanza name, and typed value
+- runtime-only prompt export values on module outputs
+- `module.Output.DataPackageValue`, which selects the prompt export value and
+  falls back to the rich value for hand-built or loaded snapshots
 - typed stanza lookup through `module.StanzaValue`
 
+## Rich Values And Prompt Exports
+
+Each `module.Output` has two value surfaces:
+
+- `Value`: the rich module value used by templates, module snapshots,
+  inspection, Recent Changes, and render contexts.
+- `PromptValue`: the runtime-only prompt export used when building Scriptorium
+  data packages.
+
+`PromptValue` is deliberately excluded from module snapshot JSON. Persisted
+module snapshots keep only the rich `value` field so inspection and
+render-context reconstruction keep the full deterministic template surface.
+
+The `internal/briefing` module registry attaches prompt export values when it
+builds module outputs. Modules without a custom exporter use default
+pass-through behavior, so their prompt value is the same as their rich value.
+Modules that need cleanup own typed prompt export structs near the module
+builder. Current custom prompt exports are:
+
+- `current_conditions`
+- `hourly_forecast`
+- `derived_daypart_summaries`
+
+Custom exporters remove template-only helpers or confusing duplicates from the
+data package without shrinking the rich module structs used by templates.
+Exporter failures include module ID and stanza context.
+
 ## Registered Module IDs
 
 The registry recognizes these IDs:
@@ -186,7 +216,7 @@ validation.
 
 ## SPC Convective Module Outputs
 
-`spc_convective_outlooks` emits a prompt-facing risk-product stanza with:
+`spc_convective_outlooks` emits a risk-product stanza with:
 
 - `checked`
 - `as_of`
@@ -221,7 +251,8 @@ meet the severity threshold.
 `module.Snapshot` values are persisted by `internal/state` as JSON. Snapshot
 validation rejects missing schema version, missing module IDs, missing stanza
 names, duplicate module outputs, and duplicate stanza names while preserving
-output order.
+output order. Snapshot JSON contains rich module values only; runtime prompt
+export values are not persisted.
 
 ## Failure Behavior
 
@@ -242,5 +273,8 @@ Inspect:
 
 - `internal/module` does not import `internal/report`.
 - Module IDs are stable strings.
-- Each emitted module output has exactly one stanza name and one typed value.
+- Each emitted module output has exactly one stanza name and one rich typed
+  value.
+- Built module outputs have a data-package value, either from a custom prompt
+  exporter or from default pass-through behavior.
 - Snapshot output order is caller-owned and preserved.

docs/internal/prompt-input.md

@@ -5,13 +5,15 @@ This document describes YAML prompt data package construction in
 
 ## Purpose
 
-`internal/promptinput` converts report metadata, an ordered module snapshot,
+`internal/promptinput` converts report metadata, ordered module outputs, Recent
-Recent Changes, and source warnings into the `data_package` file passed to
+Changes, and source warnings into the `data_package` file passed to
 Scriptorium.
 
 The persisted data package is YAML with schema version
-`weatherreporter.data_package.v2`. It is separate from the JSON module snapshot
+`weatherreporter.data_package.v3`. It is separate from the JSON module snapshot
-used for inspection and comparison.
+used for inspection and comparison. Data packages serialize each module
+output's prompt export value, not necessarily the full rich module value saved
+in the module snapshot.
 
 ## Inputs And Outputs
 
@@ -32,7 +34,7 @@ Outputs:
 The YAML shape includes:
 
 ```yaml
-schema_version: weatherreporter.data_package.v2
+schema_version: weatherreporter.data_package.v3
 run_id: <run_id>
 report:
   id: <report_id>
@@ -68,6 +70,32 @@ Prompt-facing module intervals use local `period_begins` and `period_ends`
 labels; canonical report metadata and source timestamps remain structured
 timestamps where applicable.
 
+## Module Export Boundary
+
+Data packages are curated prompt inputs. They are not full template render
+contexts and should not be treated as a dump of every field available to Go
+templates.
+
+When module outputs are built by `internal/briefing`, the registry attaches a
+runtime prompt export value. `internal/promptinput` serializes
+`output.DataPackageValue()` for each stanza. That helper prefers the runtime
+prompt export and falls back to the rich `Value` when no prompt export is set,
+which keeps loaded snapshots and hand-built tests usable.
+
+Modules without custom export policy use pass-through behavior. Modules with
+custom exports currently include:
+
+- `current_conditions`: omits lower-case condition text and duplicate
+  wind-direction text.
+- `hourly_forecast`: omits hour labels, lower-case description text, and the
+  template precipitation-mention helper while keeping forecast facts.
+- `derived_daypart_summaries`: omits deterministic sentence-construction
+  helpers while keeping daypart period, condition, temperature trend,
+  precipitation, wind, notable-condition, hazard, and alert-relevance facts.
+
+The rich module snapshot and generated-template render context still contain
+the helper fields used by deterministic Markdown templates.
+
 Daily Report, Today Report, Tomorrow Report, and Hourly Report module snapshots
 use the same package schema and categories when converted into prompt input.
 The default hourly module list places
@@ -101,8 +129,8 @@ Current categories are:
 - This package owns prompt package schema, YAML marshaling, YAML loading, and
   validation.
 - It does not fetch weather data, derive forecast summaries, execute modules,
-  find prior snapshots, compare changes, choose artifact paths, or invoke
+  choose module prompt export shapes, find prior snapshots, compare changes,
-  Scriptorium.
+  choose artifact paths, or invoke Scriptorium.
 
 ## Config Fields Used
 
@@ -142,5 +170,8 @@ Inspect:
 - Scriptorium receives structured YAML through `--input data_package=<path>`.
 - Module stanza order is deterministic within each prompt-facing category.
 - Every non-metadata module stanza has exactly one prompt-input category.
+- Data-package stanzas use curated module prompt exports when present and rich
+  values only as pass-through or fallback values.
+- Data packages are narrower than generated-template render contexts.
 - Recent Changes are provided by `internal/changes`; this package does not
   infer changes from rendered report text.

docs/operations.md

@@ -19,7 +19,7 @@ weatherreporter generate storm --start 2026-05-29T18:00 --end 2026-05-30T06:00
 ```
 
 Generation commands resolve a report period, fetch a Weather API bundle, build
-a JSON module snapshot, build a YAML prompt input data package, run
+a rich JSON module snapshot, build a curated YAML prompt input data package, run
 `scriptorium render`, and write managed artifacts under the configured
 workspace. Markdown-path reports then run `scriptorium run` directly to the
 managed Markdown report path.
@@ -287,11 +287,12 @@ weatherreporter inspect sources RUN_ID
 
 Use `inspect reports` to find RunIDs and artifact paths. Use
 `inspect metadata` to see the artifact links recorded for a run. Use
-`inspect modules` to review the persisted ordered module snapshot, and
+`inspect modules` to review the persisted ordered module snapshot with rich
-`inspect data-package` to review the structured prompt package used for
+template-facing values, and `inspect data-package` to review the curated prompt
-rendering. Use `inspect prior` to see the prior comparable snapshot selected for
+package passed to Scriptorium. Use `inspect prior` to see the prior comparable
-Recent Changes, or `null` when none exists. Use `inspect sources` to review
+snapshot selected for Recent Changes, or `null` when none exists. Use
-source provenance and warnings without dumping full weather payloads.
+`inspect sources` to review source provenance and warnings without dumping full
+weather payloads.
 
 ## Recent Changes
 

docs/roadmap/data-package-exports.md

@@ -6,8 +6,9 @@ This roadmap defines the target state for cleaning up module fields exposed in
 YAML data packages. The goal is to keep report templates composable while making
 LLM prompt inputs concise, readable, and free of template-only helper fields.
 
-This feature is not implemented yet. Current data-package behavior remains
+This feature is implemented. Current data-package behavior is documented in
-documented outside `docs/roadmap/`.
+`docs/internal/prompt-input.md`; the rich module and template boundary is
+documented in `docs/internal/module.md` and `docs/templates.md`.
 
 ## Problem
 

docs/templates.md

@@ -184,6 +184,12 @@ falls back to sorted keys for any unmatched entries.
 prompt data package. Module fields are pointers because missing-data policy may
 omit a stanza.
 
+Templates render from rich module values, not from the curated YAML data
+package. Some fields documented below are deterministic wording helpers for
+Markdown templates and are intentionally omitted from data packages passed to
+Scriptorium. The data package is a prompt input, while the render context is the
+template surface.
+
 | Variable | Type | Description |
 | --- | --- | --- |
 | `.Modules.Metadata` | *briefing.MetadataModule | Report metadata module output, when present. |
@@ -270,6 +276,40 @@ Common fields:
 | `.Modules.PrecipTiming.PrecipitationWindows[].MaxPopHourLabel` | string | Friendly hour label for the window maximum. |
 | `.Modules.PrecipTiming.ThunderMentioned` | bool | Whether thunder is mentioned in the forecast text. |
 
+### Daypart Summaries
+
+Daily, Today, and Tomorrow templates should use `.Modules.Dayparts` for
+ordered daypart rendering. Each item has `Key` and `Summary`; `Summary` is a
+rich `briefing.DerivedDaypartSummaryModule`.
+
+Common rich daypart fields:
+
+| Variable | Type | Description |
+| --- | --- | --- |
+| `.Modules.Dayparts[].Summary.DisplayName` | string | Human-readable daypart label. |
+| `.Modules.Dayparts[].Summary.PeriodBegins` | string | Friendly local daypart start. |
+| `.Modules.Dayparts[].Summary.PeriodEnds` | string | Friendly local daypart end. |
+| `.Modules.Dayparts[].Summary.TempRangeF` | string | Rounded temperature range or single temperature. |
+| `.Modules.Dayparts[].Summary.TemperaturePhraseF` | string | Temperature phrase used for steady template wording. |
+| `.Modules.Dayparts[].Summary.TemperatureTrend` | string | Trend category such as `rising`, `falling`, `peaking`, or `steady`. |
+| `.Modules.Dayparts[].Summary.TemperatureStartPhraseF` | string | Starting temperature phrase for rising/falling wording. |
+| `.Modules.Dayparts[].Summary.TemperatureEndPhraseF` | string | Ending temperature phrase for rising/falling wording. |
+| `.Modules.Dayparts[].Summary.TemperaturePeakPhraseF` | string | Peak temperature phrase for peaking wording. |
+| `.Modules.Dayparts[].Summary.TemperatureSteadyPhraseF` | string | Steady temperature phrase. |
+| `.Modules.Dayparts[].Summary.MaxPopPercent` | *int | Highest precipitation probability in the daypart. |
+| `.Modules.Dayparts[].Summary.MaxPopTime` | string | Friendly local time for the highest precipitation probability. |
+| `.Modules.Dayparts[].Summary.MaxPopTimeLabel` | string | Clock-style label for deterministic precipitation timing text. |
+| `.Modules.Dayparts[].Summary.MentionPrecipitation` | bool | True when precipitation probability should be mentioned by the template. |
+| `.Modules.Dayparts[].Summary.DominantCondition` | string | Dominant condition text. |
+| `.Modules.Dayparts[].Summary.DominantConditionLower` | string | Lower-case condition text for inline sentences. |
+| `.Modules.Dayparts[].Summary.DominantConditionDisplay` | string | Display-case condition text for bullet starts. |
+| `.Modules.Dayparts[].Summary.NotableConditions` | []string | Notable condition labels retained for the daypart. |
+
+Template-only daypart helpers such as `TemperaturePhraseF`,
+`DominantConditionLower`, `DominantConditionDisplay`, and `MaxPopTimeLabel`
+remain available here even though they are not serialized into data-package
+YAML.
+
 ### Alert Digest
 
 | Variable | Type | Description |

internal/app/app_test.go

@@ -162,6 +162,16 @@ func TestGenerateReportWritesReportAndPreflight(t *testing.T) {
 	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))
 	}
+	for _, want := range []string{`"condition_text_lower"`, `"hour_label"`, `"text_description_lower"`, `"mention_precipitation"`} {
+		if !strings.Contains(string(snapshotData), want) {
+			t.Fatalf("module snapshot missing rich helper field %q:\n%s", want, string(snapshotData))
+		}
+	}
+	for _, want := range []string{`"temperature_phrase_f"`, `"dominant_condition_lower"`, `"dominant_condition_display"`, `"max_pop_time_label"`} {
+		if !strings.Contains(string(snapshotData), want) {
+			t.Fatalf("module snapshot missing rich daypart helper field %q:\n%s", want, string(snapshotData))
+		}
+	}
 	data, err := os.ReadFile(result.DataPackagePath)
 	if err != nil {
 		t.Fatalf("read data package: %v", err)
@@ -169,7 +179,7 @@ func TestGenerateReportWritesReportAndPreflight(t *testing.T) {
 	if !strings.HasSuffix(result.DataPackagePath, ".data_package.yaml") {
 		t.Fatalf("DataPackagePath = %q, want YAML data package path", result.DataPackagePath)
 	}
-	if !strings.Contains(string(data), "schema_version: weatherreporter.data_package.v2") ||
+	if !strings.Contains(string(data), "schema_version: weatherreporter.data_package.v3") ||
 		!strings.Contains(string(data), "recent_changes:") ||
 		!strings.Contains(string(data), "applicable_risk_products:") ||
 		!strings.Contains(string(data), "derived_summaries:") ||
@@ -222,6 +232,11 @@ func TestGenerateReportWritesReportAndPreflight(t *testing.T) {
 	if !ok || current["condition_text"] != "Clear" {
 		t.Fatalf("data package current conditions = %#v, want current conditions", savedDataPackage.Briefing.Values["current_conditions"])
 	}
+	for _, omitted := range []string{"condition_text_lower", "wind_direction_text"} {
+		if _, ok := current[omitted]; ok {
+			t.Fatalf("data package current conditions contains helper field %q: %#v", omitted, current)
+		}
+	}
 	narrative, ok := savedDataPackage.Briefing.Values["narrative_forecast"].(map[string]any)
 	if !ok || narrative["product"] != "narrative" || !strings.Contains(string(data), "Morning storms, then partly sunny.") {
 		t.Fatalf("data package narrative forecast = %#v, want narrative forecast", savedDataPackage.Briefing.Values["narrative_forecast"])
@@ -230,6 +245,35 @@ func TestGenerateReportWritesReportAndPreflight(t *testing.T) {
 	if !ok || hourly["product"] != "hourly" || !strings.Contains(string(data), "Showers and thunderstorms") {
 		t.Fatalf("data package hourly forecast = %#v, want hourly forecast", savedDataPackage.Briefing.Values["hourly_forecast"])
 	}
+	periods, ok := hourly["periods"].([]any)
+	if !ok || len(periods) == 0 {
+		t.Fatalf("data package hourly periods = %#v, want prompt period rows", hourly["periods"])
+	}
+	firstPeriod, ok := periods[0].(map[string]any)
+	if !ok {
+		t.Fatalf("data package hourly first period = %#v, want mapping", periods[0])
+	}
+	for _, omitted := range []string{"hour_label", "text_description_lower", "mention_precipitation"} {
+		if _, ok := firstPeriod[omitted]; ok {
+			t.Fatalf("data package hourly period contains helper field %q: %#v", omitted, firstPeriod)
+		}
+	}
+	dayparts, ok := savedDataPackage.Briefing.Values["derived_daypart_summaries"].(map[string]any)
+	if !ok {
+		t.Fatalf("data package daypart summaries = %#v, want daypart map", savedDataPackage.Briefing.Values["derived_daypart_summaries"])
+	}
+	morning, ok := dayparts["morning"].(map[string]any)
+	if !ok {
+		t.Fatalf("data package morning daypart = %#v, want daypart map", dayparts["morning"])
+	}
+	if morning["max_pop_time"] != "6:00 AM" {
+		t.Fatalf("data package morning max_pop_time = %#v, want friendly label", morning["max_pop_time"])
+	}
+	for _, omitted := range []string{"temperature_phrase_f", "dominant_condition_lower", "dominant_condition_display", "max_pop_time_label"} {
+		if _, ok := morning[omitted]; ok {
+			t.Fatalf("data package morning daypart contains helper field %q: %#v", omitted, morning)
+		}
+	}
 	story, ok := savedDataPackage.Briefing.Values["weather_story"].(map[string]any)
 	if !ok || story["title"] != "Several Chances for Rain Through Monday" {
 		t.Fatalf("data package weather story = %#v, want weather story title", savedDataPackage.Briefing.Values["weather_story"])
@@ -265,6 +309,80 @@ func TestGenerateReportWritesReportAndPreflight(t *testing.T) {
 	}
 }
 
+func TestGeneratedTemplateReportsUseRichArtifactsAndCuratedDataPackages(t *testing.T) {
+	server := dailyBundleServer(t)
+	tests := []struct {
+		name   string
+		kind   ReportKind
+		date   time.Time
+		now    time.Time
+		prompt string
+	}{
+		{
+			name:   "today",
+			kind:   ReportToday,
+			date:   mustParse("2026-05-29T12:00:00-05:00"),
+			now:    mustParse("2026-05-29T05:00:00-05:00"),
+			prompt: "weather.today_generated_text",
+		},
+		{
+			name:   "tomorrow",
+			kind:   ReportTomorrow,
+			now:    mustParse("2026-05-29T18:00:00-05:00"),
+			prompt: "weather.tomorrow_generated_text",
+		},
+		{
+			name:   "daily",
+			kind:   ReportDaily,
+			date:   mustParse("2026-05-29T12:00:00-05:00"),
+			now:    mustParse("2026-05-29T05:00:00-05:00"),
+			prompt: "weather.daily_generated_text",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cfg := dailyTestConfig(t, server)
+			cfg.Workspace.Root = t.TempDir()
+			resolved, err := ResolveGenerate(GenerateRequest{
+				Config: cfg,
+				Report: tt.kind,
+				Date:   tt.date,
+			}, tt.now)
+			if err != nil {
+				t.Fatalf("ResolveGenerate() error = %v", err)
+			}
+			renderer := &recordingRenderer{
+				renderResult:        &scriptorium.RenderResult{ExitCode: 0},
+				structuredRunResult: &scriptorium.StructuredRunResult{ExitCode: 0},
+			}
+
+			result, err := GenerateReport(context.Background(), ReportRequest{
+				Config:   cfg,
+				Resolved: resolved,
+				Renderer: renderer,
+			})
+			if err != nil {
+				t.Fatalf("GenerateReport() error = %v", err)
+			}
+			if renderer.renderCalls != 1 || renderer.structuredRunCalls != 1 || renderer.runCalls != 0 {
+				t.Fatalf("renderer calls render=%d structured=%d run=%d, want generated-template workflow", renderer.renderCalls, renderer.structuredRunCalls, renderer.runCalls)
+			}
+			if renderer.renderRequest.PromptID != tt.prompt || renderer.structuredRunRequest.PromptID != tt.prompt {
+				t.Fatalf("prompt IDs render=%q structured=%q, want %q", renderer.renderRequest.PromptID, renderer.structuredRunRequest.PromptID, tt.prompt)
+			}
+			if renderer.renderRequest.DataPackagePath != result.DataPackagePath {
+				t.Fatalf("render DataPackagePath = %q, want managed path %q", renderer.renderRequest.DataPackagePath, result.DataPackagePath)
+			}
+			if renderer.structuredRunRequest.DataPackagePath != result.DataPackagePath {
+				t.Fatalf("structured run DataPackagePath = %q, want managed path %q", renderer.structuredRunRequest.DataPackagePath, result.DataPackagePath)
+			}
+			assertRichPromptHelperArtifacts(t, result)
+			assertCuratedPromptDataPackage(t, result)
+		})
+	}
+}
+
 func TestGenerateReportIncludesSPCConvectivePromptStanzas(t *testing.T) {
 	server := dailyBundleServerWithConvectiveResponse(t, qualifyingConvectiveOutlooksResponse)
 	cfg := dailyTestConfig(t, server)
@@ -2611,6 +2729,98 @@ func readDataPackageForTest(t *testing.T, result *ReportResult) []byte {
 	return data
 }
 
+func assertRichPromptHelperArtifacts(t *testing.T, result *ReportResult) {
+	t.Helper()
+	snapshotData, err := os.ReadFile(result.ModuleSnapshotPath)
+	if err != nil {
+		t.Fatalf("read module snapshot: %v", err)
+	}
+	for _, want := range []string{
+		`"condition_text_lower"`,
+		`"hour_label"`,
+		`"text_description_lower"`,
+		`"mention_precipitation"`,
+		`"temperature_phrase_f"`,
+		`"dominant_condition_lower"`,
+		`"dominant_condition_display"`,
+		`"max_pop_time_label"`,
+	} {
+		if !strings.Contains(string(snapshotData), want) {
+			t.Fatalf("module snapshot missing rich helper field %q:\n%s", want, string(snapshotData))
+		}
+	}
+
+	renderContext, err := os.ReadFile(result.RenderContextPath)
+	if err != nil {
+		t.Fatalf("read render context: %v", err)
+	}
+	for _, want := range []string{
+		`"condition_text_lower"`,
+		`"hour_label"`,
+		`"text_description_lower"`,
+		`"mention_precipitation"`,
+		`"temperature_phrase_f"`,
+		`"dominant_condition_lower"`,
+		`"dominant_condition_display"`,
+		`"max_pop_time_label"`,
+	} {
+		if !strings.Contains(string(renderContext), want) {
+			t.Fatalf("render context missing rich helper field %q:\n%s", want, string(renderContext))
+		}
+	}
+}
+
+func assertCuratedPromptDataPackage(t *testing.T, result *ReportResult) {
+	t.Helper()
+	data := readDataPackageForTest(t, result)
+	pkg, err := promptinput.LoadYAML(data)
+	if err != nil {
+		t.Fatalf("decode data package: %v", err)
+	}
+
+	current, ok := pkg.Briefing.Values["current_conditions"].(map[string]any)
+	if !ok {
+		t.Fatalf("current_conditions = %#v, want prompt map", pkg.Briefing.Values["current_conditions"])
+	}
+	assertMapOmitsKeys(t, "current_conditions", current, "condition_text_lower", "wind_direction_text")
+
+	hourly, ok := pkg.Briefing.Values["hourly_forecast"].(map[string]any)
+	if !ok {
+		t.Fatalf("hourly_forecast = %#v, want prompt map", pkg.Briefing.Values["hourly_forecast"])
+	}
+	periods, ok := hourly["periods"].([]any)
+	if !ok || len(periods) == 0 {
+		t.Fatalf("hourly_forecast.periods = %#v, want prompt periods", hourly["periods"])
+	}
+	firstPeriod, ok := periods[0].(map[string]any)
+	if !ok {
+		t.Fatalf("hourly first period = %#v, want prompt map", periods[0])
+	}
+	assertMapOmitsKeys(t, "hourly_forecast.periods[0]", firstPeriod, "hour_label", "text_description_lower", "mention_precipitation")
+
+	dayparts, ok := pkg.Briefing.Values["derived_daypart_summaries"].(map[string]any)
+	if !ok {
+		t.Fatalf("derived_daypart_summaries = %#v, want prompt map", pkg.Briefing.Values["derived_daypart_summaries"])
+	}
+	morning, ok := dayparts["morning"].(map[string]any)
+	if !ok {
+		t.Fatalf("derived_daypart_summaries.morning = %#v, want prompt map", dayparts["morning"])
+	}
+	if morning["max_pop_time"] != "6:00 AM" {
+		t.Fatalf("derived_daypart_summaries.morning.max_pop_time = %#v, want friendly label", morning["max_pop_time"])
+	}
+	assertMapOmitsKeys(t, "derived_daypart_summaries.morning", morning, "temperature_phrase_f", "dominant_condition_lower", "dominant_condition_display", "max_pop_time_label")
+}
+
+func assertMapOmitsKeys(t *testing.T, name string, value map[string]any, keys ...string) {
+	t.Helper()
+	for _, key := range keys {
+		if _, ok := value[key]; ok {
+			t.Fatalf("%s contains helper field %q: %#v", name, key, value)
+		}
+	}
+}
+
 func assertNoStaleModuleIntervalKeys(t *testing.T, values map[string]any) {
 	t.Helper()
 	for name, value := range values {

internal/briefing/base_modules_test.go

@@ -89,6 +89,48 @@ func TestHourlyForecastModuleUsesValidPeriodHourlyPeriods(t *testing.T) {
 	}
 }
 
+func TestHourlyForecastPromptExportOmitsTemplateHelpers(t *testing.T) {
+	registry := MustDefaultModuleRegistry()
+	ctx := testModuleContext()
+
+	output, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.HourlyForecast})
+	if err != nil {
+		t.Fatalf("BuildModule() error = %v", err)
+	}
+	richText := mustMarshalModuleJSON(t, output.Value)
+	for _, field := range []string{"hour_label", "text_description_lower", "mention_precipitation"} {
+		if !strings.Contains(richText, field) {
+			t.Fatalf("rich hourly json = %s, want helper field %s", richText, field)
+		}
+	}
+
+	prompt := moduleDataPackageValue[HourlyForecastPromptExport](t, output)
+	if prompt.Product != "hourly" || prompt.SourceLocationID != "test-grid" || len(prompt.Periods) != 1 {
+		t.Fatalf("hourly prompt export = %#v, want hourly metadata and one period", prompt)
+	}
+	period := prompt.Periods[0]
+	if period.PeriodBegins != "2026-05-29 at 8:00 AM" || period.PeriodEnds != "2026-05-29 at 9:00 AM" || period.TextDescription != "Showers likely." {
+		t.Fatalf("hourly prompt period = %#v, want factual period fields", period)
+	}
+	if period.TemperatureF == nil || *period.TemperatureF != 76 || period.WindSpeedMph == nil || *period.WindSpeedMph != 14 || period.ProbabilityOfPrecipitationPercent == nil || *period.ProbabilityOfPrecipitationPercent != 70 {
+		t.Fatalf("hourly prompt period = %#v, want temperature, wind, and precip fields", period)
+	}
+	if period.WindDirection != "S" || period.RelativeHumidityPercent == nil || *period.RelativeHumidityPercent != 66 {
+		t.Fatalf("hourly prompt period = %#v, want wind direction and humidity", period)
+	}
+	promptText := mustMarshalModuleJSON(t, output.DataPackageValue())
+	for _, field := range []string{"period_begins", "period_ends", "text_description", "temperature_f", "wind_direction", "probability_of_precipitation_percent", "relative_humidity_percent"} {
+		if !strings.Contains(promptText, field) {
+			t.Fatalf("hourly prompt json = %s, want field %s", promptText, field)
+		}
+	}
+	for _, field := range []string{"hour_label", "text_description_lower", "mention_precipitation"} {
+		if strings.Contains(promptText, field) {
+			t.Fatalf("hourly prompt json = %s, want omitted helper field %s", promptText, field)
+		}
+	}
+}
+
 func TestHourlyForecastPrecipMentionThreshold(t *testing.T) {
 	periods := []weatherdata.ForecastPeriod{
 		{StartTime: mustParseModuleTime("2026-05-29T08:00:00-05:00"), ProbabilityOfPrecipitationPercent: floatPtr(19)},
@@ -260,6 +302,44 @@ func TestCurrentConditionsModuleUsesSnakeCaseUnitFields(t *testing.T) {
 	}
 }
 
+func TestCurrentConditionsPromptExportOmitsTemplateHelpers(t *testing.T) {
+	registry := MustDefaultModuleRegistry()
+	ctx := testModuleContext()
+
+	output, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.CurrentConditions})
+	if err != nil {
+		t.Fatalf("BuildModule() error = %v", err)
+	}
+	richText := mustMarshalModuleJSON(t, output.Value)
+	for _, field := range []string{"condition_text_lower", "wind_direction_text"} {
+		if !strings.Contains(richText, field) {
+			t.Fatalf("rich current conditions json = %s, want helper field %s", richText, field)
+		}
+	}
+
+	prompt := moduleDataPackageValue[CurrentConditionsPromptExport](t, output)
+	if prompt.ConditionText != "Partly cloudy" || prompt.TemperatureF == nil || *prompt.TemperatureF != 74 {
+		t.Fatalf("current prompt export = %#v, want condition text and temperature", prompt)
+	}
+	if prompt.ApparentTemperatureF == nil || *prompt.ApparentTemperatureF != 76 || prompt.RelativeHumidityPercent == nil || *prompt.RelativeHumidityPercent != 71 || prompt.WindSpeedMph == nil || *prompt.WindSpeedMph != 8 {
+		t.Fatalf("current prompt export = %#v, want apparent temperature, humidity, and wind speed", prompt)
+	}
+	if prompt.WindDirection != "S" {
+		t.Fatalf("current prompt wind direction = %q, want S", prompt.WindDirection)
+	}
+	promptText := mustMarshalModuleJSON(t, output.DataPackageValue())
+	for _, field := range []string{"condition_text", "temperature_f", "apparent_temperature_f", "relative_humidity_percent", "wind_speed_mph", "wind_direction"} {
+		if !strings.Contains(promptText, field) {
+			t.Fatalf("current prompt json = %s, want field %s", promptText, field)
+		}
+	}
+	for _, field := range []string{"condition_text_lower", "wind_direction_text"} {
+		if strings.Contains(promptText, field) {
+			t.Fatalf("current prompt json = %s, want omitted helper field %s", promptText, field)
+		}
+	}
+}
+
 func TestAlertDigestDistinguishesCheckedEmptyAndMissing(t *testing.T) {
 	registry := MustDefaultModuleRegistry()
 	ctx := testModuleContext()
@@ -563,6 +643,28 @@ func moduleValue[T any](t *testing.T, output *module.Output) T {
 	return value
 }
 
+func moduleDataPackageValue[T any](t *testing.T, output *module.Output) T {
+	t.Helper()
+	var value T
+	data, err := json.Marshal(output.DataPackageValue())
+	if err != nil {
+		t.Fatalf("marshal module data package value: %v", err)
+	}
+	if err := json.Unmarshal(data, &value); err != nil {
+		t.Fatalf("decode module data package value: %v", err)
+	}
+	return value
+}
+
+func mustMarshalModuleJSON(t *testing.T, value any) string {
+	t.Helper()
+	data, err := json.Marshal(value)
+	if err != nil {
+		t.Fatalf("marshal module value: %v", err)
+	}
+	return string(data)
+}
+
 func mustParseModuleTime(value string) time.Time {
 	parsed, err := time.Parse(time.RFC3339, value)
 	if err != nil {

internal/briefing/current_conditions_module.go

@@ -23,6 +23,21 @@ type CurrentConditionsModule struct {
 	WindDirectionText       string `json:"wind_direction_text,omitempty"`
 }
 
+type CurrentConditionsPromptExport struct {
+	ConditionText           string `json:"condition_text,omitempty"`
+	IsDay                   *bool  `json:"is_day,omitempty"`
+	TemperatureC            *int   `json:"temperature_c,omitempty"`
+	TemperatureF            *int   `json:"temperature_f,omitempty"`
+	ApparentTemperatureC    *int   `json:"apparent_temperature_c,omitempty"`
+	ApparentTemperatureF    *int   `json:"apparent_temperature_f,omitempty"`
+	DewpointC               *int   `json:"dewpoint_c,omitempty"`
+	DewpointF               *int   `json:"dewpoint_f,omitempty"`
+	RelativeHumidityPercent *int   `json:"relative_humidity_percent,omitempty"`
+	WindSpeedKmh            *int   `json:"wind_speed_kmh,omitempty"`
+	WindSpeedMph            *int   `json:"wind_speed_mph,omitempty"`
+	WindDirection           string `json:"wind_direction,omitempty"`
+}
+
 func buildCurrentConditionsModule(ctx ModuleContext, _ any) (*module.Output, error) {
 	current := ctx.Collected.Current
 	if current == nil {
@@ -50,6 +65,27 @@ func buildCurrentConditionsModule(ctx ModuleContext, _ any) (*module.Output, err
 	return &module.Output{ID: module.CurrentConditions, StanzaName: "current_conditions", Value: value}, nil
 }
 
+func exportCurrentConditionsPromptValue(value any) (any, error) {
+	rich, ok := value.(CurrentConditionsModule)
+	if !ok {
+		return nil, unexpectedPromptExportValue(value, CurrentConditionsModule{})
+	}
+	return CurrentConditionsPromptExport{
+		ConditionText:           rich.ConditionText,
+		IsDay:                   copyBool(rich.IsDay),
+		TemperatureC:            copyInt(rich.TemperatureC),
+		TemperatureF:            copyInt(rich.TemperatureF),
+		ApparentTemperatureC:    copyInt(rich.ApparentTemperatureC),
+		ApparentTemperatureF:    copyInt(rich.ApparentTemperatureF),
+		DewpointC:               copyInt(rich.DewpointC),
+		DewpointF:               copyInt(rich.DewpointF),
+		RelativeHumidityPercent: copyInt(rich.RelativeHumidityPercent),
+		WindSpeedKmh:            copyInt(rich.WindSpeedKmh),
+		WindSpeedMph:            copyInt(rich.WindSpeedMph),
+		WindDirection:           rich.WindDirection,
+	}, nil
+}
+
 func (v CurrentConditionsModule) isEmpty() bool {
 	return v.ConditionText == "" &&
 		v.ConditionTextLower == "" &&

internal/briefing/derived_daypart_summaries_module.go

@@ -44,6 +44,34 @@ type DerivedDaypartSummaryModule struct {
 	RelevantAlertCount       int      `json:"relevant_alert_count,omitempty"`
 }
 
+type DerivedDaypartSummaryPromptExport struct {
+	Date                     string   `json:"date,omitempty"`
+	DisplayName              string   `json:"display_name,omitempty"`
+	PeriodBegins             string   `json:"period_begins,omitempty"`
+	PeriodEnds               string   `json:"period_ends,omitempty"`
+	TempRangeF               string   `json:"temp_range_f,omitempty"`
+	ApparentTempRangeF       string   `json:"apparent_temp_range_f,omitempty"`
+	MaxPopPercent            *int     `json:"max_pop_percent,omitempty"`
+	MaxPopTime               string   `json:"max_pop_time,omitempty"`
+	MentionPrecipitation     bool     `json:"mention_precipitation,omitempty"`
+	MaxWindGustMph           *int     `json:"max_wind_gust_mph,omitempty"`
+	MaxWindGustTime          string   `json:"max_wind_gust_time,omitempty"`
+	DominantCondition        string   `json:"dominant_condition,omitempty"`
+	TemperatureTrend         string   `json:"temperature_trend,omitempty"`
+	TemperatureStartPhraseF  string   `json:"temperature_start_phrase_f,omitempty"`
+	TemperatureEndPhraseF    string   `json:"temperature_end_phrase_f,omitempty"`
+	TemperaturePeakPhraseF   string   `json:"temperature_peak_phrase_f,omitempty"`
+	TemperatureSteadyPhraseF string   `json:"temperature_steady_phrase_f,omitempty"`
+	NotableConditions        []string `json:"notable_conditions,omitempty"`
+	Snow                     bool     `json:"snow,omitempty"`
+	Ice                      bool     `json:"ice,omitempty"`
+	Fog                      bool     `json:"fog,omitempty"`
+	Heat                     bool     `json:"heat,omitempty"`
+	Cold                     bool     `json:"cold,omitempty"`
+	Wind                     bool     `json:"wind,omitempty"`
+	RelevantAlertCount       int      `json:"relevant_alert_count,omitempty"`
+}
+
 func buildDerivedDaypartSummariesModule(ctx ModuleContext, _ any) (*module.Output, error) {
 	if len(ctx.Derived.DaypartSummaries) == 0 {
 		return nil, fmt.Errorf("daypart summary facts are required")
@@ -57,6 +85,52 @@ func buildDerivedDaypartSummariesModule(ctx ModuleContext, _ any) (*module.Outpu
 	return &module.Output{ID: module.DerivedDaypartSummaries, StanzaName: "derived_daypart_summaries", Value: value}, nil
 }
 
+func exportDerivedDaypartSummariesPromptValue(value any) (any, error) {
+	rich, ok := value.(map[string]DerivedDaypartSummaryModule)
+	if !ok {
+		return nil, unexpectedPromptExportValue(value, map[string]DerivedDaypartSummaryModule{})
+	}
+	out := make(map[string]DerivedDaypartSummaryPromptExport, len(rich))
+	for key, daypart := range rich {
+		out[key] = derivedDaypartSummaryPromptValue(daypart)
+	}
+	return out, nil
+}
+
+func derivedDaypartSummaryPromptValue(rich DerivedDaypartSummaryModule) DerivedDaypartSummaryPromptExport {
+	maxPopTime := rich.MaxPopTime
+	if rich.MaxPopTimeLabel != "" {
+		maxPopTime = rich.MaxPopTimeLabel
+	}
+	return DerivedDaypartSummaryPromptExport{
+		Date:                     rich.Date,
+		DisplayName:              rich.DisplayName,
+		PeriodBegins:             rich.PeriodBegins,
+		PeriodEnds:               rich.PeriodEnds,
+		TempRangeF:               rich.TempRangeF,
+		ApparentTempRangeF:       rich.ApparentTempRangeF,
+		MaxPopPercent:            copyInt(rich.MaxPopPercent),
+		MaxPopTime:               maxPopTime,
+		MentionPrecipitation:     rich.MentionPrecipitation,
+		MaxWindGustMph:           copyInt(rich.MaxWindGustMph),
+		MaxWindGustTime:          rich.MaxWindGustTime,
+		DominantCondition:        rich.DominantCondition,
+		TemperatureTrend:         rich.TemperatureTrend,
+		TemperatureStartPhraseF:  rich.TemperatureStartPhraseF,
+		TemperatureEndPhraseF:    rich.TemperatureEndPhraseF,
+		TemperaturePeakPhraseF:   rich.TemperaturePeakPhraseF,
+		TemperatureSteadyPhraseF: rich.TemperatureSteadyPhraseF,
+		NotableConditions:        append([]string(nil), rich.NotableConditions...),
+		Snow:                     rich.Snow,
+		Ice:                      rich.Ice,
+		Fog:                      rich.Fog,
+		Heat:                     rich.Heat,
+		Cold:                     rich.Cold,
+		Wind:                     rich.Wind,
+		RelevantAlertCount:       rich.RelevantAlertCount,
+	}
+}
+
 func derivedDaypartSummaryValue(daypart forecast.DaypartSummary, timezone string) DerivedDaypartSummaryModule {
 	temperature := daypartTemperatureDisplay(daypart)
 	value := DerivedDaypartSummaryModule{

internal/briefing/derived_modules_test.go

@@ -201,6 +201,126 @@ func TestDerivedDaypartSummariesExposeConfiguredKeysAndHazards(t *testing.T) {
 	}
 }
 
+func TestDerivedDaypartSummariesPromptExportOmitsTemplateHelpers(t *testing.T) {
+	registry := MustDefaultModuleRegistry()
+	ctx := derivedModuleContext(report.Daily)
+
+	output, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.DerivedDaypartSummaries})
+	if err != nil {
+		t.Fatalf("BuildModule() error = %v", err)
+	}
+	richText := mustMarshalModuleJSON(t, output.Value)
+	for _, field := range []string{"temperature_phrase_f", "dominant_condition_lower", "dominant_condition_display", "max_pop_time_label"} {
+		if !strings.Contains(richText, field) {
+			t.Fatalf("rich daypart json = %s, want helper field %s", richText, field)
+		}
+	}
+
+	prompt := moduleDataPackageValue[map[string]DerivedDaypartSummaryPromptExport](t, output)
+	morning, ok := prompt["morning"]
+	if !ok {
+		t.Fatalf("daypart prompt keys = %#v, want morning", prompt)
+	}
+	if morning.Date != "2026-05-29" || morning.DisplayName != "Morning" || morning.PeriodBegins != "2026-05-29 at 6:00 AM" || morning.PeriodEnds != "2026-05-29 at 12:00 PM" {
+		t.Fatalf("morning prompt period = %#v, want date/display/period labels", morning)
+	}
+	if morning.TempRangeF != "58" || morning.MaxPopPercent == nil || *morning.MaxPopPercent != 60 || morning.MaxPopTime != "6:00 AM" || !morning.MentionPrecipitation {
+		t.Fatalf("morning prompt precip/temp = %#v, want factual prompt fields with friendly max pop time", morning)
+	}
+	if morning.DominantCondition != "Showers" || morning.TemperatureTrend != "steady" || morning.TemperatureSteadyPhraseF != "upper 50s" {
+		t.Fatalf("morning prompt condition/trend = %#v, want condition and trend fields", morning)
+	}
+	if len(morning.NotableConditions) == 0 || morning.NotableConditions[0] != "Showers" {
+		t.Fatalf("morning prompt notable conditions = %#v, want copied conditions", morning.NotableConditions)
+	}
+	afternoon := prompt["afternoon"]
+	if !afternoon.Heat || !afternoon.Wind || afternoon.MaxWindGustMph == nil || *afternoon.MaxWindGustMph != 42 || afternoon.RelevantAlertCount != 1 {
+		t.Fatalf("afternoon prompt = %#v, want hazard, wind, and alert fields", afternoon)
+	}
+
+	promptText := mustMarshalModuleJSON(t, output.DataPackageValue())
+	for _, field := range []string{"date", "display_name", "period_begins", "period_ends", "temp_range_f", "max_pop_percent", "max_pop_time", "mention_precipitation", "max_wind_gust_mph", "dominant_condition", "temperature_trend", "temperature_steady_phrase_f", "notable_conditions", "relevant_alert_count"} {
+		if !strings.Contains(promptText, field) {
+			t.Fatalf("daypart prompt json = %s, want field %s", promptText, field)
+		}
+	}
+	for _, field := range []string{"temperature_phrase_f", "dominant_condition_lower", "dominant_condition_display", "max_pop_time_label"} {
+		if strings.Contains(promptText, field) {
+			t.Fatalf("daypart prompt json = %s, want omitted helper field %s", promptText, field)
+		}
+	}
+}
+
+func TestDerivedDaypartPromptExportTemperatureTrends(t *testing.T) {
+	tests := []struct {
+		name       string
+		temps      []float64
+		wantTrend  string
+		wantStart  string
+		wantEnd    string
+		wantPeak   string
+		wantSteady string
+	}{
+		{
+			name:      "rising",
+			temps:     []float64{58, 68},
+			wantTrend: "rising",
+			wantStart: "upper 50s",
+			wantEnd:   "upper 60s",
+		},
+		{
+			name:      "falling",
+			temps:     []float64{65, 58},
+			wantTrend: "falling",
+			wantStart: "mid 60s",
+			wantEnd:   "upper 50s",
+		},
+		{
+			name:      "peaking",
+			temps:     []float64{62, 78, 65},
+			wantTrend: "peaking",
+			wantPeak:  "upper 70s",
+		},
+		{
+			name:       "steady",
+			temps:      []float64{77, 78},
+			wantTrend:  "steady",
+			wantSteady: "upper 70s",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			rich := derivedDaypartSummaryValue(derivedDaypartWithTemperatures(test.name, "2026-05-29T12:00:00-05:00", "sunny", test.temps...), "America/Chicago")
+			prompt := derivedDaypartSummaryPromptValue(rich)
+			if prompt.TemperatureTrend != test.wantTrend ||
+				prompt.TemperatureStartPhraseF != test.wantStart ||
+				prompt.TemperatureEndPhraseF != test.wantEnd ||
+				prompt.TemperaturePeakPhraseF != test.wantPeak ||
+				prompt.TemperatureSteadyPhraseF != test.wantSteady {
+				t.Fatalf("prompt temperature presentation = %#v", prompt)
+			}
+		})
+	}
+}
+
+func TestDerivedDaypartPromptExportMaxPopTimeFallback(t *testing.T) {
+	withLabel := derivedDaypartSummaryPromptValue(DerivedDaypartSummaryModule{
+		MaxPopTime:      "6 AM",
+		MaxPopTimeLabel: "6:00 AM",
+	})
+	if withLabel.MaxPopTime != "6:00 AM" {
+		t.Fatalf("MaxPopTime with label = %q, want friendly label", withLabel.MaxPopTime)
+	}
+
+	withoutLabel := derivedDaypartSummaryPromptValue(DerivedDaypartSummaryModule{
+		MaxPopTime: "6 AM",
+	})
+	if withoutLabel.MaxPopTime != "6 AM" {
+		t.Fatalf("MaxPopTime without label = %q, want fallback time", withoutLabel.MaxPopTime)
+	}
+}
+
 func TestDerivedDaypartTemperaturePresentationFields(t *testing.T) {
 	tests := []struct {
 		name       string

internal/briefing/hourly_forecast_module.go

@@ -20,6 +20,15 @@ type HourlyForecastModule struct {
 	Periods          []HourlyForecastPeriod `json:"periods,omitempty"`
 }
 
+type HourlyForecastPromptExport struct {
+	Product          string                       `json:"product,omitempty"`
+	IssuedAt         time.Time                    `json:"issued_at,omitempty"`
+	UpdatedAt        *time.Time                   `json:"updated_at,omitempty"`
+	SourceLocation   string                       `json:"source_location,omitempty"`
+	SourceLocationID string                       `json:"source_location_id,omitempty"`
+	Periods          []HourlyForecastPromptPeriod `json:"periods,omitempty"`
+}
+
 type HourlyForecastPeriod struct {
 	HourLabel                         string   `json:"hour_label,omitempty"`
 	PeriodBegins                      string   `json:"period_begins,omitempty"`
@@ -59,6 +68,42 @@ type HourlyForecastPeriod struct {
 	RelativeHumidityPercent           *float64 `json:"relative_humidity_percent,omitempty"`
 }
 
+type HourlyForecastPromptPeriod struct {
+	PeriodBegins                      string   `json:"period_begins,omitempty"`
+	PeriodEnds                        string   `json:"period_ends,omitempty"`
+	Name                              string   `json:"name,omitempty"`
+	IsDay                             *bool    `json:"is_day,omitempty"`
+	ConditionCode                     *int     `json:"condition_code,omitempty"`
+	TextDescription                   string   `json:"text_description,omitempty"`
+	TemperatureC                      *float64 `json:"temperature_c,omitempty"`
+	TemperatureF                      *float64 `json:"temperature_f,omitempty"`
+	TemperatureCMin                   *float64 `json:"temperature_c_min,omitempty"`
+	TemperatureFMin                   *float64 `json:"temperature_f_min,omitempty"`
+	TemperatureCMax                   *float64 `json:"temperature_c_max,omitempty"`
+	TemperatureFMax                   *float64 `json:"temperature_f_max,omitempty"`
+	DewpointC                         *float64 `json:"dewpoint_c,omitempty"`
+	DewpointF                         *float64 `json:"dewpoint_f,omitempty"`
+	WindSpeedKmh                      *float64 `json:"wind_speed_kmh,omitempty"`
+	WindSpeedMph                      *float64 `json:"wind_speed_mph,omitempty"`
+	WindGustKmh                       *float64 `json:"wind_gust_kmh,omitempty"`
+	WindGustMph                       *float64 `json:"wind_gust_mph,omitempty"`
+	WindDirection                     string   `json:"wind_direction,omitempty"`
+	BarometricPressurePa              *float64 `json:"barometric_pressure_pa,omitempty"`
+	BarometricPressureInHg            *float64 `json:"barometric_pressure_in_hg,omitempty"`
+	VisibilityMeters                  *float64 `json:"visibility_meters,omitempty"`
+	VisibilityMiles                   *float64 `json:"visibility_miles,omitempty"`
+	ApparentTemperatureC              *float64 `json:"apparent_temperature_c,omitempty"`
+	ApparentTemperatureF              *float64 `json:"apparent_temperature_f,omitempty"`
+	CloudCoverPercent                 *float64 `json:"cloud_cover_percent,omitempty"`
+	ProbabilityOfPrecipitationPercent *float64 `json:"probability_of_precipitation_percent,omitempty"`
+	PrecipitationAmountMm             *float64 `json:"precipitation_amount_mm,omitempty"`
+	PrecipitationAmountIn             *float64 `json:"precipitation_amount_in,omitempty"`
+	SnowfallDepthMM                   *float64 `json:"snowfall_depth_mm,omitempty"`
+	SnowfallDepthIn                   *float64 `json:"snowfall_depth_in,omitempty"`
+	UVIndex                           *float64 `json:"uv_index,omitempty"`
+	RelativeHumidityPercent           *float64 `json:"relative_humidity_percent,omitempty"`
+}
+
 func buildHourlyForecastModule(ctx ModuleContext, _ any) (*module.Output, error) {
 	hourly := ctx.Collected.Hourly
 	if hourly == nil || len(ctx.Derived.ValidPeriodHourlyPeriods) == 0 {
@@ -78,6 +123,66 @@ func buildHourlyForecastModule(ctx ModuleContext, _ any) (*module.Output, error)
 	return &module.Output{ID: module.HourlyForecast, StanzaName: "hourly_forecast", Value: value}, nil
 }
 
+func exportHourlyForecastPromptValue(value any) (any, error) {
+	rich, ok := value.(HourlyForecastModule)
+	if !ok {
+		return nil, unexpectedPromptExportValue(value, HourlyForecastModule{})
+	}
+	return HourlyForecastPromptExport{
+		Product:          rich.Product,
+		IssuedAt:         rich.IssuedAt,
+		UpdatedAt:        copyTime(rich.UpdatedAt),
+		SourceLocation:   rich.SourceLocation,
+		SourceLocationID: rich.SourceLocationID,
+		Periods:          hourlyForecastPromptPeriods(rich.Periods),
+	}, nil
+}
+
+func hourlyForecastPromptPeriods(periods []HourlyForecastPeriod) []HourlyForecastPromptPeriod {
+	if len(periods) == 0 {
+		return nil
+	}
+	out := make([]HourlyForecastPromptPeriod, 0, len(periods))
+	for _, period := range periods {
+		out = append(out, HourlyForecastPromptPeriod{
+			PeriodBegins:                      period.PeriodBegins,
+			PeriodEnds:                        period.PeriodEnds,
+			Name:                              period.Name,
+			IsDay:                             copyBool(period.IsDay),
+			ConditionCode:                     copyInt(period.ConditionCode),
+			TextDescription:                   period.TextDescription,
+			TemperatureC:                      copyFloat(period.TemperatureC),
+			TemperatureF:                      copyFloat(period.TemperatureF),
+			TemperatureCMin:                   copyFloat(period.TemperatureCMin),
+			TemperatureFMin:                   copyFloat(period.TemperatureFMin),
+			TemperatureCMax:                   copyFloat(period.TemperatureCMax),
+			TemperatureFMax:                   copyFloat(period.TemperatureFMax),
+			DewpointC:                         copyFloat(period.DewpointC),
+			DewpointF:                         copyFloat(period.DewpointF),
+			WindSpeedKmh:                      copyFloat(period.WindSpeedKmh),
+			WindSpeedMph:                      copyFloat(period.WindSpeedMph),
+			WindGustKmh:                       copyFloat(period.WindGustKmh),
+			WindGustMph:                       copyFloat(period.WindGustMph),
+			WindDirection:                     period.WindDirection,
+			BarometricPressurePa:              copyFloat(period.BarometricPressurePa),
+			BarometricPressureInHg:            copyFloat(period.BarometricPressureInHg),
+			VisibilityMeters:                  copyFloat(period.VisibilityMeters),
+			VisibilityMiles:                   copyFloat(period.VisibilityMiles),
+			ApparentTemperatureC:              copyFloat(period.ApparentTemperatureC),
+			ApparentTemperatureF:              copyFloat(period.ApparentTemperatureF),
+			CloudCoverPercent:                 copyFloat(period.CloudCoverPercent),
+			ProbabilityOfPrecipitationPercent: copyFloat(period.ProbabilityOfPrecipitationPercent),
+			PrecipitationAmountMm:             copyFloat(period.PrecipitationAmountMm),
+			PrecipitationAmountIn:             copyFloat(period.PrecipitationAmountIn),
+			SnowfallDepthMM:                   copyFloat(period.SnowfallDepthMM),
+			SnowfallDepthIn:                   copyFloat(period.SnowfallDepthIn),
+			UVIndex:                           copyFloat(period.UVIndex),
+			RelativeHumidityPercent:           copyFloat(period.RelativeHumidityPercent),
+		})
+	}
+	return out
+}
+
 func hourlyForecastPeriods(periods []weatherdata.ForecastPeriod, timezone string) []HourlyForecastPeriod {
 	return hourlyForecastPeriodsWithPrecipMentionThreshold(periods, timezone, DefaultHourlyForecastPrecipMentionProbabilityThreshold)
 }

internal/briefing/modules.go

@@ -21,6 +21,8 @@ type ModuleContext struct {
 
 type ModuleBuilder func(ModuleContext, any) (*module.Output, error)
 
+type ModulePromptExporter func(value any) (any, error)
+
 type ModuleDefinition struct {
 	ID                module.ID
 	StanzaName        string
@@ -31,12 +33,17 @@ type ModuleDefinition struct {
 	MissingData       module.MissingDataBehavior
 	AllowDuplicate    bool
 	Builder           ModuleBuilder
+	PromptExporter    ModulePromptExporter
 }
 
 type ModuleRegistry struct {
 	definitions map[module.ID]ModuleDefinition
 }
 
+func unexpectedPromptExportValue(got any, want any) error {
+	return fmt.Errorf("value has type %T, want %T", got, want)
+}
+
 func DefaultModuleRegistry() (ModuleRegistry, error) {
 	return NewModuleRegistry(defaultModuleDefinitions())
 }
@@ -130,6 +137,15 @@ func (r ModuleRegistry) BuildModule(ctx ModuleContext, item module.ConfigItem) (
 	if output.StanzaName != definition.StanzaName {
 		return nil, fmt.Errorf("module %q produced stanza %q, want %q", definition.ID, output.StanzaName, definition.StanzaName)
 	}
+	if definition.PromptExporter == nil {
+		output.PromptValue = output.Value
+		return output, nil
+	}
+	promptValue, err := definition.PromptExporter(output.Value)
+	if err != nil {
+		return nil, fmt.Errorf("module %q stanza %q prompt export: %w", definition.ID, definition.StanzaName, err)
+	}
+	output.PromptValue = promptValue
 	return output, nil
 }
 
@@ -269,6 +285,7 @@ func defaultModuleDefinitions() []ModuleDefinition {
 			SupportedReports:  allReports,
 			MissingData:       module.MissingDataOmit,
 			Builder:           buildCurrentConditionsModule,
+			PromptExporter:    exportCurrentConditionsPromptValue,
 		},
 		{
 			ID:                module.NarrativeForecast,
@@ -289,6 +306,7 @@ func defaultModuleDefinitions() []ModuleDefinition {
 			SupportedReports:  []report.ID{report.Daily, report.Today, report.Tomorrow, report.Hourly},
 			MissingData:       module.MissingDataOmit,
 			Builder:           buildHourlyForecastModule,
+			PromptExporter:    exportHourlyForecastPromptValue,
 		},
 		{
 			ID:               module.DerivedDailySummary,
@@ -307,6 +325,7 @@ func defaultModuleDefinitions() []ModuleDefinition {
 			SupportedReports: daypartReports,
 			MissingData:      module.MissingDataError,
 			Builder:          buildDerivedDaypartSummariesModule,
+			PromptExporter:   exportDerivedDaypartSummariesPromptValue,
 		},
 		{
 			ID:               module.PrecipTiming,

internal/briefing/modules_test.go

@@ -1,6 +1,8 @@
 package briefing
 
 import (
+	"encoding/json"
+	"errors"
 	"strings"
 	"testing"
 
@@ -40,6 +42,9 @@ func TestDefaultReportModulesBuildSnapshots(t *testing.T) {
 					t.Fatalf("BuildModule(%s) error = %v", item.ID, err)
 				}
 				if output != nil {
+					if output.DataPackageValue() == nil {
+						t.Fatalf("BuildModule(%s) data package value = nil", item.ID)
+					}
 					outputs = append(outputs, *output)
 				}
 			}
@@ -54,6 +59,210 @@ func TestDefaultReportModulesBuildSnapshots(t *testing.T) {
 	}
 }
 
+func TestDefaultModuleDefinitionsDeclarePromptExportPolicy(t *testing.T) {
+	customExporters := map[module.ID]struct{}{
+		module.CurrentConditions:       {},
+		module.HourlyForecast:          {},
+		module.DerivedDaypartSummaries: {},
+	}
+	passThroughExporters := map[module.ID]struct{}{
+		module.Metadata:                {},
+		module.NarrativeForecast:       {},
+		module.DerivedDailySummary:     {},
+		module.PrecipTiming:            {},
+		module.AlertDigest:             {},
+		module.SPCConvectiveOutlooks:   {},
+		module.AreaForecastDiscussion:  {},
+		module.SPCConvectiveDiscussion: {},
+		module.WeatherStory:            {},
+		module.OutdoorWindows:          {},
+		module.TodayPlanning:           {},
+		module.TomorrowPlanning:        {},
+		module.DailyPlanning:           {},
+	}
+
+	for _, definition := range defaultModuleDefinitions() {
+		_, custom := customExporters[definition.ID]
+		_, passThrough := passThroughExporters[definition.ID]
+		if custom == passThrough {
+			t.Fatalf("module %q exporter policy custom=%v passThrough=%v, want exactly one policy", definition.ID, custom, passThrough)
+		}
+		if custom && definition.PromptExporter == nil {
+			t.Fatalf("module %q PromptExporter = nil, want custom prompt exporter", definition.ID)
+		}
+		if passThrough && definition.PromptExporter != nil {
+			t.Fatalf("module %q PromptExporter is set, want default pass-through", definition.ID)
+		}
+	}
+}
+
+func TestModuleRegistryAddsPassThroughPromptValue(t *testing.T) {
+	registry, err := NewModuleRegistry([]ModuleDefinition{
+		{
+			ID:         module.Metadata,
+			StanzaName: "metadata",
+			Builder: func(ModuleContext, any) (*module.Output, error) {
+				return &module.Output{
+					ID:         module.Metadata,
+					StanzaName: "metadata",
+					Value:      testRegistryValue{Message: "rich"},
+				}, nil
+			},
+		},
+	})
+	if err != nil {
+		t.Fatalf("NewModuleRegistry() error = %v", err)
+	}
+
+	output, err := registry.BuildModule(testRegistryModuleContext(), module.ConfigItem{ID: module.Metadata})
+	if err != nil {
+		t.Fatalf("BuildModule() error = %v", err)
+	}
+	if output == nil {
+		t.Fatal("BuildModule() output = nil, want output")
+	}
+	if output.PromptValue != output.Value {
+		t.Fatalf("PromptValue = %#v, want pass-through rich value %#v", output.PromptValue, output.Value)
+	}
+	if output.DataPackageValue() != output.Value {
+		t.Fatalf("DataPackageValue() = %#v, want rich value", output.DataPackageValue())
+	}
+}
+
+func TestModuleRegistryAddsCustomPromptValue(t *testing.T) {
+	registry, err := NewModuleRegistry([]ModuleDefinition{
+		{
+			ID:         module.Metadata,
+			StanzaName: "metadata",
+			Builder: func(ModuleContext, any) (*module.Output, error) {
+				return &module.Output{
+					ID:         module.Metadata,
+					StanzaName: "metadata",
+					Value:      testRegistryValue{Message: "rich"},
+				}, nil
+			},
+			PromptExporter: func(value any) (any, error) {
+				rich, ok := value.(testRegistryValue)
+				if !ok {
+					return nil, errors.New("unexpected rich value type")
+				}
+				return testRegistryValue{Message: rich.Message + " prompt"}, nil
+			},
+		},
+	})
+	if err != nil {
+		t.Fatalf("NewModuleRegistry() error = %v", err)
+	}
+
+	output, err := registry.BuildModule(testRegistryModuleContext(), module.ConfigItem{ID: module.Metadata})
+	if err != nil {
+		t.Fatalf("BuildModule() error = %v", err)
+	}
+	got, ok := output.PromptValue.(testRegistryValue)
+	if !ok {
+		t.Fatalf("PromptValue type = %T, want testRegistryValue", output.PromptValue)
+	}
+	if got.Message != "rich prompt" {
+		t.Fatalf("PromptValue = %#v, want custom prompt value", got)
+	}
+	if output.DataPackageValue() != output.PromptValue {
+		t.Fatalf("DataPackageValue() = %#v, want custom prompt value", output.DataPackageValue())
+	}
+	if output.Value.(testRegistryValue).Message != "rich" {
+		t.Fatalf("Value = %#v, want rich value unchanged", output.Value)
+	}
+}
+
+func TestModuleRegistryWrapsPromptExporterErrors(t *testing.T) {
+	registry, err := NewModuleRegistry([]ModuleDefinition{
+		{
+			ID:         module.Metadata,
+			StanzaName: "metadata",
+			Builder: func(ModuleContext, any) (*module.Output, error) {
+				return &module.Output{ID: module.Metadata, StanzaName: "metadata", Value: testRegistryValue{Message: "rich"}}, nil
+			},
+			PromptExporter: func(any) (any, error) {
+				return nil, errors.New("unsupported value")
+			},
+		},
+	})
+	if err != nil {
+		t.Fatalf("NewModuleRegistry() error = %v", err)
+	}
+
+	_, err = registry.BuildModule(testRegistryModuleContext(), module.ConfigItem{ID: module.Metadata})
+	if err == nil ||
+		!strings.Contains(err.Error(), `module "metadata" stanza "metadata" prompt export`) ||
+		!strings.Contains(err.Error(), "unsupported value") {
+		t.Fatalf("BuildModule() error = %v, want wrapped exporter error", err)
+	}
+}
+
+func TestModuleRegistryValidatesOutputBeforePromptExport(t *testing.T) {
+	called := false
+	registry, err := NewModuleRegistry([]ModuleDefinition{
+		{
+			ID:         module.Metadata,
+			StanzaName: "metadata",
+			Builder: func(ModuleContext, any) (*module.Output, error) {
+				return &module.Output{ID: module.CurrentConditions, StanzaName: "metadata", Value: testRegistryValue{Message: "rich"}}, nil
+			},
+			PromptExporter: func(any) (any, error) {
+				called = true
+				return testRegistryValue{Message: "prompt"}, nil
+			},
+		},
+	})
+	if err != nil {
+		t.Fatalf("NewModuleRegistry() error = %v", err)
+	}
+
+	_, err = registry.BuildModule(testRegistryModuleContext(), module.ConfigItem{ID: module.Metadata})
+	if err == nil || !strings.Contains(err.Error(), `module "metadata" produced output id "current_conditions"`) {
+		t.Fatalf("BuildModule() error = %v, want output id validation error", err)
+	}
+	if called {
+		t.Fatal("PromptExporter called before output validation")
+	}
+}
+
+func TestModuleRegistryPromptValueIsNotPersistedInSnapshotJSON(t *testing.T) {
+	registry, err := NewModuleRegistry([]ModuleDefinition{
+		{
+			ID:         module.Metadata,
+			StanzaName: "metadata",
+			Builder: func(ModuleContext, any) (*module.Output, error) {
+				return &module.Output{ID: module.Metadata, StanzaName: "metadata", Value: testRegistryValue{Message: "rich"}}, nil
+			},
+			PromptExporter: func(any) (any, error) {
+				return testRegistryValue{Message: "prompt-only"}, nil
+			},
+		},
+	})
+	if err != nil {
+		t.Fatalf("NewModuleRegistry() error = %v", err)
+	}
+	output, err := registry.BuildModule(testRegistryModuleContext(), module.ConfigItem{ID: module.Metadata})
+	if err != nil {
+		t.Fatalf("BuildModule() error = %v", err)
+	}
+	snapshot, err := module.NewSnapshot([]module.Output{*output})
+	if err != nil {
+		t.Fatalf("NewSnapshot() error = %v", err)
+	}
+	data, err := json.Marshal(snapshot)
+	if err != nil {
+		t.Fatalf("Marshal() error = %v", err)
+	}
+	text := string(data)
+	if !strings.Contains(text, `"message":"rich"`) {
+		t.Fatalf("snapshot JSON missing rich value: %s", text)
+	}
+	if strings.Contains(text, "prompt-only") || strings.Contains(text, "promptValue") || strings.Contains(text, "PromptValue") {
+		t.Fatalf("snapshot JSON includes runtime-only prompt value: %s", text)
+	}
+}
+
 func TestHourlyDefaultModuleOptions(t *testing.T) {
 	definition := report.DefaultRegistry().MustLookup(report.Hourly)
 	var found bool
@@ -250,3 +459,15 @@ func TestSPCConvectiveOutlookDerivedRequirementAvailability(t *testing.T) {
 func noopModuleBuilder(ModuleContext, any) (*module.Output, error) {
 	return &module.Output{ID: module.Metadata, StanzaName: "metadata", Value: struct{}{}}, nil
 }
+
+type testRegistryValue struct {
+	Message string `json:"message"`
+}
+
+func testRegistryModuleContext() ModuleContext {
+	return ModuleContext{
+		Resolved: report.Resolved{
+			Definition: report.DefaultRegistry().MustLookup(report.Daily),
+		},
+	}
+}

internal/cli/root_test.go

@@ -540,7 +540,7 @@ func TestRunGenerateDailyWritesMarkdownReport(t *testing.T) {
 	if err != nil {
 		t.Fatalf("read managed data package: %v", err)
 	}
-	if !strings.Contains(string(data), "schema_version: weatherreporter.data_package.v2") || !strings.Contains(string(data), "id: daily") {
+	if !strings.Contains(string(data), "schema_version: weatherreporter.data_package.v3") || !strings.Contains(string(data), "id: daily") {
 		t.Fatalf("data package output missing expected content:\n%s", string(data))
 	}
 	if !strings.Contains(string(data), "location:") ||

internal/generatedtext/render_context_test.go

@@ -44,12 +44,18 @@ func TestBuildHourlyRenderContext(t *testing.T) {
 	if ctx.Modules.CurrentConditions == nil || ctx.Modules.CurrentConditions.ConditionText != "Partly cloudy" || ctx.Modules.CurrentConditions.TemperatureF == nil || *ctx.Modules.CurrentConditions.TemperatureF != 74 {
 		t.Fatalf("Modules.CurrentConditions = %#v, want structured current conditions", ctx.Modules.CurrentConditions)
 	}
+	if ctx.Modules.CurrentConditions.ConditionTextLower != "partly cloudy" || ctx.Modules.CurrentConditions.WindDirectionText != "south" {
+		t.Fatalf("Modules.CurrentConditions helpers = %#v, want rich template helper fields", ctx.Modules.CurrentConditions)
+	}
 	if ctx.Modules.HourlyForecast == nil || len(ctx.Modules.HourlyForecast.Periods) != 2 {
 		t.Fatalf("Modules.HourlyForecast = %#v, want 2 periods", ctx.Modules.HourlyForecast)
 	}
 	if period := ctx.Modules.HourlyForecast.Periods[1]; period.PeriodBegins != "2026-05-29 at 10:00 AM" || period.TextDescription != "Showers" || period.ProbabilityOfPrecipitationPercent == nil || *period.ProbabilityOfPrecipitationPercent != 70 {
 		t.Fatalf("Modules.HourlyForecast.Periods[1] = %#v, want 10 AM showers row", period)
 	}
+	if period := ctx.Modules.HourlyForecast.Periods[1]; period.HourLabel != "10:00 AM" || period.TextDescriptionLower != "showers" || !period.MentionPrecipitation {
+		t.Fatalf("Modules.HourlyForecast.Periods[1] helpers = %#v, want rich template helper fields", period)
+	}
 	if ctx.Modules.PrecipTiming == nil || ctx.Modules.PrecipTiming.MaxPopPercent == nil || *ctx.Modules.PrecipTiming.MaxPopPercent != 70 {
 		t.Fatalf("Modules.PrecipTiming = %#v, want max pop", ctx.Modules.PrecipTiming)
 	}
@@ -178,6 +184,12 @@ func TestBuildTodayRenderContext(t *testing.T) {
 	if len(ctx.Modules.Dayparts) != 2 || ctx.Modules.Dayparts[0].Key != "morning" || ctx.Modules.Dayparts[1].Key != "afternoon" {
 		t.Fatalf("Modules.Dayparts = %#v, want configured order", ctx.Modules.Dayparts)
 	}
+	if morning := (*ctx.Modules.DerivedDaypartSummaries)["morning"]; morning.DominantConditionDisplay == "" || morning.DominantConditionLower == "" || morning.TemperatureSteadyPhraseF == "" {
+		t.Fatalf("today rich morning daypart helpers = %#v, want render-context helper fields", morning)
+	}
+	if afternoon := (*ctx.Modules.DerivedDaypartSummaries)["afternoon"]; afternoon.MaxPopTimeLabel != "3:00 PM" {
+		t.Fatalf("today rich afternoon daypart = %#v, want max pop time label helper", afternoon)
+	}
 	if ctx.Modules.PrecipTiming == nil || len(ctx.Modules.PrecipTiming.PrecipitationWindows) != 1 {
 		t.Fatalf("Modules.PrecipTiming = %#v, want precipitation window", ctx.Modules.PrecipTiming)
 	}
@@ -305,6 +317,12 @@ func TestBuildDailyRenderContext(t *testing.T) {
 	if len(ctx.Modules.Dayparts) != 3 || ctx.Modules.Dayparts[0].Key != "morning" || ctx.Modules.Dayparts[1].Key != "afternoon" || ctx.Modules.Dayparts[2].Key != "evening" {
 		t.Fatalf("Modules.Dayparts = %#v, want derived order followed by remaining keys", ctx.Modules.Dayparts)
 	}
+	if morning := (*ctx.Modules.DerivedDaypartSummaries)["morning"]; morning.DominantConditionDisplay == "" || morning.DominantConditionLower == "" || morning.TemperatureSteadyPhraseF == "" {
+		t.Fatalf("daily rich morning daypart helpers = %#v, want render-context helper fields", morning)
+	}
+	if afternoon := (*ctx.Modules.DerivedDaypartSummaries)["afternoon"]; afternoon.MaxPopTimeLabel != "3:00 PM" {
+		t.Fatalf("daily rich afternoon daypart = %#v, want max pop time label helper", afternoon)
+	}
 	if ctx.Modules.PrecipTiming == nil || len(ctx.Modules.PrecipTiming.PrecipitationWindows) != 1 {
 		t.Fatalf("Modules.PrecipTiming = %#v, want precipitation window", ctx.Modules.PrecipTiming)
 	}
@@ -428,6 +446,12 @@ func TestBuildTomorrowRenderContext(t *testing.T) {
 	if len(ctx.Modules.Dayparts) != 2 || ctx.Modules.Dayparts[0].Key != "morning" || ctx.Modules.Dayparts[1].Key != "afternoon" {
 		t.Fatalf("Modules.Dayparts = %#v, want configured order", ctx.Modules.Dayparts)
 	}
+	if morning := (*ctx.Modules.DerivedDaypartSummaries)["morning"]; morning.DominantConditionDisplay == "" || morning.DominantConditionLower == "" || morning.TemperatureSteadyPhraseF == "" {
+		t.Fatalf("tomorrow rich morning daypart helpers = %#v, want render-context helper fields", morning)
+	}
+	if afternoon := (*ctx.Modules.DerivedDaypartSummaries)["afternoon"]; afternoon.MaxPopTimeLabel != "3:00 PM" {
+		t.Fatalf("tomorrow rich afternoon daypart = %#v, want max pop time label helper", afternoon)
+	}
 	if ctx.Modules.PrecipTiming == nil || len(ctx.Modules.PrecipTiming.PrecipitationWindows) != 1 {
 		t.Fatalf("Modules.PrecipTiming = %#v, want precipitation window", ctx.Modules.PrecipTiming)
 	}

internal/module/module.go

@@ -35,9 +35,10 @@ type ConfigItem struct {
 }
 
 type Output struct {
-	ID         ID     `json:"id"`
+	ID          ID     `json:"id"`
-	StanzaName string `json:"stanzaName"`
+	StanzaName  string `json:"stanzaName"`
-	Value      any    `json:"value"`
+	Value       any    `json:"value"`
+	PromptValue any    `json:"-" yaml:"-"`
 }
 
 type Snapshot struct {
@@ -45,6 +46,13 @@ type Snapshot struct {
 	Outputs       []Output `json:"outputs"`
 }
 
+func (o Output) DataPackageValue() any {
+	if o.PromptValue != nil {
+		return o.PromptValue
+	}
+	return o.Value
+}
+
 func NewSnapshot(outputs []Output) (Snapshot, error) {
 	snapshot := Snapshot{
 		SchemaVersion: SnapshotSchemaVersion,

internal/module/module_test.go

@@ -13,7 +13,12 @@ type testStanza struct {
 
 func TestSnapshotPreservesOutputOrderAndJSON(t *testing.T) {
 	snapshot, err := NewSnapshot([]Output{
-		{ID: Metadata, StanzaName: "metadata", Value: testStanza{Message: "first", Count: 1}},
+		{
+			ID:          Metadata,
+			StanzaName:  "metadata",
+			Value:       testStanza{Message: "first", Count: 1},
+			PromptValue: testStanza{Message: "prompt-only", Count: 10},
+		},
 		{ID: AlertDigest, StanzaName: "alert_digest", Value: testStanza{Message: "second", Count: 2}},
 	})
 	if err != nil {
@@ -35,6 +40,26 @@ func TestSnapshotPreservesOutputOrderAndJSON(t *testing.T) {
 	if got != want {
 		t.Fatalf("json = %s, want %s", got, want)
 	}
+	if strings.Contains(got, "PromptValue") || strings.Contains(got, "promptValue") || strings.Contains(got, "prompt-only") {
+		t.Fatalf("json includes runtime-only prompt value: %s", got)
+	}
+}
+
+func TestOutputDataPackageValue(t *testing.T) {
+	output := Output{
+		ID:          Metadata,
+		StanzaName:  "metadata",
+		Value:       testStanza{Message: "rich", Count: 1},
+		PromptValue: testStanza{Message: "prompt", Count: 2},
+	}
+	if got := output.DataPackageValue(); got != output.PromptValue {
+		t.Fatalf("DataPackageValue() = %#v, want prompt value", got)
+	}
+
+	output.PromptValue = nil
+	if got := output.DataPackageValue(); got != output.Value {
+		t.Fatalf("DataPackageValue() = %#v, want rich value fallback", got)
+	}
 }
 
 func TestSnapshotRejectsDuplicateOutputs(t *testing.T) {
@@ -57,7 +82,12 @@ func TestSnapshotRejectsDuplicateOutputs(t *testing.T) {
 
 func TestStanzaValueDecodesTypedOutput(t *testing.T) {
 	snapshot, err := NewSnapshot([]Output{
-		{ID: Metadata, StanzaName: "metadata", Value: testStanza{Message: "available", Count: 3}},
+		{
+			ID:          Metadata,
+			StanzaName:  "metadata",
+			Value:       testStanza{Message: "available", Count: 3},
+			PromptValue: testStanza{Message: "prompt-only", Count: 99},
+		},
 	})
 	if err != nil {
 		t.Fatalf("NewSnapshot() error = %v", err)

internal/promptinput/package.go

@@ -16,7 +16,7 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
-const SchemaVersion = "weatherreporter.data_package.v2"
+const SchemaVersion = "weatherreporter.data_package.v3"
 
 const (
 	metadataStanza                 = "metadata"
@@ -133,7 +133,7 @@ func stanzasFromSnapshot(snapshot module.Snapshot) BriefingStanzas {
 	order := make([]string, 0, len(snapshot.Outputs))
 	for _, output := range snapshot.Outputs {
 		order = append(order, output.StanzaName)
-		values[output.StanzaName] = output.Value
+		values[output.StanzaName] = output.DataPackageValue()
 	}
 	return BriefingStanzas{Order: order, Values: values}
 }

internal/promptinput/package_test.go

@@ -126,6 +126,44 @@ func TestBuildUsesNamedSnapshotStanzas(t *testing.T) {
 	}
 }
 
+func TestBuildUsesPromptValuesFromSnapshot(t *testing.T) {
+	req := validBuildRequest(t)
+	req.Modules = snapshotWithOutputs(t,
+		module.Output{
+			ID:          module.Metadata,
+			StanzaName:  "metadata",
+			Value:       map[string]string{"run_id": "rich"},
+			PromptValue: map[string]string{"run_id": "prompt"},
+		},
+		module.Output{
+			ID:          module.CurrentConditions,
+			StanzaName:  "current_conditions",
+			Value:       map[string]string{"condition_text": "Rich conditions"},
+			PromptValue: map[string]string{"condition_text": "Prompt conditions"},
+		},
+		module.Output{
+			ID:         module.AlertDigest,
+			StanzaName: "alert_digest",
+			Value:      map[string]bool{"checked": true},
+		},
+	)
+
+	pkg, err := Build(req)
+	if err != nil {
+		t.Fatalf("Build() error = %v", err)
+	}
+
+	if got := pkg.Briefing.Values["metadata"].(map[string]string)["run_id"]; got != "prompt" {
+		t.Fatalf("metadata.run_id = %q, want prompt value", got)
+	}
+	if got := pkg.Briefing.Values["current_conditions"].(map[string]string)["condition_text"]; got != "Prompt conditions" {
+		t.Fatalf("current_conditions.condition_text = %q, want prompt value", got)
+	}
+	if got := pkg.Briefing.Values["alert_digest"].(map[string]bool)["checked"]; !got {
+		t.Fatalf("alert_digest.checked = %v, want rich value fallback", got)
+	}
+}
+
 func TestMarshalYAMLIsDeterministicAndGroupsNamedStanzas(t *testing.T) {
 	pkg, err := Build(validBuildRequest(t))
 	if err != nil {
@@ -143,7 +181,7 @@ func TestMarshalYAMLIsDeterministicAndGroupsNamedStanzas(t *testing.T) {
 	if string(first) != string(second) {
 		t.Fatalf("YAML output changed between marshals:\n%s\n---\n%s", string(first), string(second))
 	}
-	if !strings.Contains(string(first), "schema_version: weatherreporter.data_package.v2") ||
+	if !strings.Contains(string(first), "schema_version: weatherreporter.data_package.v3") ||
 		!strings.Contains(string(first), "briefing:\n") ||
 		!strings.Contains(string(first), "  applicable_risk_products:\n") ||
 		!strings.Contains(string(first), "  derived_summaries:\n") ||
@@ -251,7 +289,7 @@ func TestMarshalYAMLRejectsUncategorizedStanza(t *testing.T) {
 
 func TestLoadYAMLRejectsMisplacedStanza(t *testing.T) {
 	data := []byte(`
-schema_version: weatherreporter.data_package.v2
+schema_version: weatherreporter.data_package.v3
 run_id: 20260529T100000Z_daily
 report:
   id: daily
@@ -278,6 +316,23 @@ recent_changes:
 	}
 }
 
+func TestLoadYAMLRejectsOldSchemaVersion(t *testing.T) {
+	pkg, err := Build(validBuildRequest(t))
+	if err != nil {
+		t.Fatalf("Build() error = %v", err)
+	}
+	data, err := MarshalYAML(pkg)
+	if err != nil {
+		t.Fatalf("MarshalYAML() error = %v", err)
+	}
+	data = []byte(strings.Replace(string(data), "weatherreporter.data_package.v3", "weatherreporter.data_package.v2", 1))
+
+	_, err = LoadYAML(data)
+	if err == nil || !strings.Contains(err.Error(), "schemaVersion must be weatherreporter.data_package.v3") {
+		t.Fatalf("LoadYAML() error = %v, want current schema version error", err)
+	}
+}
+
 func validBuildRequest(t *testing.T) BuildRequest {
 	t.Helper()
 	generatedAt := time.Date(2026, 5, 29, 10, 0, 0, 0, time.UTC)

internal/reporttemplate/reporttemplate_test.go

@@ -578,6 +578,84 @@ func TestRenderToday(t *testing.T) {
 	}
 }
 
+func TestRenderDaypartTemplatesUseRichHelperFields(t *testing.T) {
+	tests := []struct {
+		name     string
+		template string
+		context  any
+		want     []string
+	}{
+		{
+			name:     "daily",
+			template: "daily",
+			context: testDailyRenderContext{
+				Report:        testDailyReportContext{Title: "Daily", ForecastDateLabel: "Monday, June 15, 2026"},
+				GeneratedText: testDailyGeneratedText{Summary: "Daily summary."},
+				Modules: testDailyModules{Dayparts: []testDailyDaypart{
+					{Key: "morning", Summary: testDaypartSummary{
+						DisplayName:              "Morning",
+						DominantConditionDisplay: "Showers",
+						TemperaturePhraseF:       "upper 60s",
+					}},
+				}},
+			},
+			want: []string{"- **Morning:** Showers, with temperatures in the upper 60s."},
+		},
+		{
+			name:     "today",
+			template: "today",
+			context: testTodayRenderContext{
+				Report:        testTodayReportContext{Title: "Today", ForecastDateLabel: "Monday, June 15, 2026"},
+				GeneratedText: testTomorrowGeneratedText{Summary: "Today summary."},
+				Modules: testTodayModules{Dayparts: []testTomorrowDaypart{
+					{Key: "afternoon", Summary: testDaypartSummary{
+						DisplayName:              "Afternoon",
+						DominantConditionDisplay: "Storms",
+						TemperaturePeakPhraseF:   "low 80s",
+						TemperatureTrend:         "peaking",
+						MaxPopPercent:            intPtr(70),
+						MentionPrecipitation:     true,
+					}},
+				}},
+			},
+			want: []string{"- **Afternoon:** Storms, with temperatures peaking in the low 80s. Chance of precipitation is 70%."},
+		},
+		{
+			name:     "tomorrow",
+			template: "tomorrow",
+			context: testTomorrowRenderContext{
+				Report:        testTomorrowReportContext{Title: "Tomorrow", ForecastDateLabel: "Tuesday, June 16, 2026"},
+				GeneratedText: testTomorrowGeneratedText{Summary: "Tomorrow summary."},
+				Modules: testTomorrowModules{Dayparts: []testTomorrowDaypart{
+					{Key: "morning", Summary: testDaypartSummary{
+						DisplayName:              "Morning",
+						DominantConditionDisplay: "Clear",
+						TemperatureStartPhraseF:  "upper 50s",
+						TemperatureEndPhraseF:    "upper 60s",
+						TemperatureTrend:         "rising",
+					}},
+				}},
+			},
+			want: []string{"- **Morning:** Clear, with temperatures rising from the upper 50s to the upper 60s."},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			rendered, err := Render(tt.template, tt.context)
+			if err != nil {
+				t.Fatalf("Render() error = %v", err)
+			}
+			text := string(rendered)
+			for _, want := range tt.want {
+				if !strings.Contains(text, want) {
+					t.Fatalf("rendered template missing %q:\n%s", want, text)
+				}
+			}
+		})
+	}
+}
+
 func TestRenderTomorrowOmitsPrecipitationTimingWithoutWindows(t *testing.T) {
 	rendered, err := Render("tomorrow", testTomorrowRenderContext{
 		Report: testTomorrowReportContext{

internal/state/filesystem_test.go

@@ -114,7 +114,12 @@ func TestSaveArtifactsAndMetadataRoundTrip(t *testing.T) {
 	store := newTestStore(t)
 	resolved := resolveDailyAt(t, "2026-05-29T05:00:00-05:00")
 	briefingMetadata := stateBriefingMetadata(resolved)
-	snapshot, err := module.NewSnapshot([]module.Output{{ID: module.Metadata, StanzaName: "metadata", Value: map[string]string{"run_id": resolved.Metadata().RunID}}})
+	snapshot, err := module.NewSnapshot([]module.Output{{
+		ID:          module.Metadata,
+		StanzaName:  "metadata",
+		Value:       map[string]string{"run_id": resolved.Metadata().RunID},
+		PromptValue: map[string]string{"prompt_run_id": resolved.Metadata().RunID},
+	}})
 	if err != nil {
 		t.Fatalf("NewSnapshot() error = %v", err)
 	}
@@ -220,6 +225,16 @@ func TestSaveArtifactsAndMetadataRoundTrip(t *testing.T) {
 	if loadedSnapshot.SchemaVersion != module.SnapshotSchemaVersion || len(loadedSnapshot.Outputs) != 1 {
 		t.Fatalf("loaded module snapshot = %#v, want one metadata output", loadedSnapshot)
 	}
+	if loadedSnapshot.Outputs[0].PromptValue != nil {
+		t.Fatalf("loaded module snapshot PromptValue = %#v, want omitted runtime value", loadedSnapshot.Outputs[0].PromptValue)
+	}
+	snapshotData, err := os.ReadFile(moduleSnapshotPath)
+	if err != nil {
+		t.Fatalf("read module snapshot: %v", err)
+	}
+	if strings.Contains(string(snapshotData), "prompt_run_id") || strings.Contains(string(snapshotData), "promptValue") || strings.Contains(string(snapshotData), "PromptValue") {
+		t.Fatalf("module snapshot JSON includes runtime-only prompt value:\n%s", string(snapshotData))
+	}
 	loadedDataPackage, err := store.LoadDataPackage(context.Background(), dataPackagePath)
 	if err != nil {
 		t.Fatalf("LoadDataPackage() error = %v", err)
@@ -227,6 +242,10 @@ func TestSaveArtifactsAndMetadataRoundTrip(t *testing.T) {
 	if loadedDataPackage.SchemaVersion != promptinput.SchemaVersion || loadedDataPackage.Briefing.Order[0] != "metadata" {
 		t.Fatalf("loaded data package = %#v, want YAML package with metadata stanza", loadedDataPackage)
 	}
+	metadataStanza, ok := loadedDataPackage.Briefing.Values["metadata"].(map[string]any)
+	if !ok || metadataStanza["prompt_run_id"] != resolved.Metadata().RunID {
+		t.Fatalf("loaded data package metadata = %#v, want runtime prompt value", loadedDataPackage.Briefing.Values["metadata"])
+	}
 	var decoded Metadata
 	data, err := os.ReadFile(metadataPath)
 	if err != nil {