Add transcript line workflow rules

MeetingAssistant/Recording/ITranscriptStore.cs

@@ -14,11 +14,30 @@ public interface ITranscriptStore
         return CreateSessionAsync(cancellationToken);
     }
 
-    Task AppendAsync(TranscriptSession session, TranscriptionSegment segment, CancellationToken cancellationToken);
+    Task AppendAsync(TranscriptSession session, TranscriptionSegment segment, CancellationToken cancellationToken)
+    {
+        return AppendLineAsync(
+            session,
+            TranscriptLineFormatter.Format(segment).Line,
+            cancellationToken);
+    }
+
+    Task AppendLineAsync(TranscriptSession session, string line, CancellationToken cancellationToken);
 
     Task ReplaceAsync(
         TranscriptSession session,
         IReadOnlyList<TranscriptionSegment> replacementSegments,
+        CancellationToken cancellationToken)
+    {
+        return ReplaceLinesAsync(
+            session,
+            replacementSegments.Select(segment => TranscriptLineFormatter.Format(segment).Line).ToList(),
+            cancellationToken);
+    }
+
+    Task ReplaceLinesAsync(
+        TranscriptSession session,
+        IReadOnlyList<string> replacementLines,
         CancellationToken cancellationToken);
 
     Task UpdateMetadataAsync(
@@ -29,3 +48,26 @@ public interface ITranscriptStore
 }
 
 public sealed record TranscriptSession(string TranscriptPath);
+
+public static class TranscriptLineFormatter
+{
+    public static FormattedTranscriptLine Format(TranscriptionSegment segment)
+    {
+        var speaker = NormalizeSpeaker(segment.Speaker);
+        return new FormattedTranscriptLine(
+            $"[{segment.Start:hh\\:mm\\:ss}] {speaker}: {segment.Text}",
+            speaker);
+    }
+
+    public static string FormatSegmentLine(TranscriptionSegment segment)
+    {
+        return Format(segment).Line;
+    }
+
+    public static string NormalizeSpeaker(string? speaker)
+    {
+        return string.IsNullOrWhiteSpace(speaker) ? "Unknown" : speaker;
+    }
+}
+
+public sealed record FormattedTranscriptLine(string Line, string Speaker);

MeetingAssistant/Recording/MeetingRecordingCoordinator.cs

@@ -433,7 +433,7 @@ public sealed class MeetingRecordingCoordinator
                     "System",
                     $"Transcription profile changed to {targetProfile.Name}.");
                 run.AddLiveSegment(marker);
-                await transcriptStore.AppendAsync(run.Session, marker, cancellationToken);
+                await AppendTranscriptSegmentAsync(run, marker, cancellationToken);
 
                 run.ReplacePipeline(pipeline, pipelineOptions, targetProfile.Options, targetProfile.Name);
                 run.AddLiveTranscriptTask(Task.Run(
@@ -598,10 +598,48 @@ public sealed class MeetingRecordingCoordinator
 
             var relabeledSegment = run.Relabel(segment);
             run.AddLiveSegment(relabeledSegment);
-            await transcriptStore.AppendAsync(run.Session, relabeledSegment, cancellationToken);
+            await AppendTranscriptSegmentAsync(run, relabeledSegment, cancellationToken);
         }
     }
 
+    private async Task AppendTranscriptSegmentAsync(
+        RecordingRun run,
+        TranscriptionSegment segment,
+        CancellationToken cancellationToken)
+    {
+        var line = await TransformTranscriptLineAsync(run, segment, cancellationToken);
+        await transcriptStore.AppendLineAsync(run.Session, line, cancellationToken);
+    }
+
+    private async Task ReplaceTranscriptSegmentsAsync(
+        RecordingRun run,
+        IReadOnlyList<TranscriptionSegment> segments,
+        CancellationToken cancellationToken)
+    {
+        var lines = new List<string>(segments.Count);
+        foreach (var segment in segments)
+        {
+            lines.Add(await TransformTranscriptLineAsync(run, segment, cancellationToken));
+        }
+
+        await transcriptStore.ReplaceLinesAsync(run.Session, lines, cancellationToken);
+    }
+
+    private async Task<string> TransformTranscriptLineAsync(
+        RecordingRun run,
+        TranscriptionSegment segment,
+        CancellationToken cancellationToken)
+    {
+        var formatted = TranscriptLineFormatter.Format(segment);
+        return await meetingWorkflowEngine.TransformTranscriptLineAsync(
+            MeetingWorkflowEvent.TranscriptLine(
+                run.Artifacts,
+                formatted.Line,
+                formatted.Speaker),
+            run.Options,
+            cancellationToken);
+    }
+
     private async Task RunInactivitySafeguardAsync(RecordingRun run)
     {
         var safeguardOptions = run.Options.Recording.InactivitySafeguard;
@@ -778,8 +816,8 @@ public sealed class MeetingRecordingCoordinator
                 cancellationToken);
             if (run.AddSpeakerMappings(result.SpeakerMappings))
             {
-                await transcriptStore.ReplaceAsync(
-                    run.Session,
+                await ReplaceTranscriptSegmentsAsync(
+                    run,
                     run.GetRelabeledLiveSegmentsSnapshot(),
                     cancellationToken);
             }
@@ -995,7 +1033,7 @@ public sealed class MeetingRecordingCoordinator
                 liveSegments.Count,
                 liveSamples.Count,
                 liveMappings.Count);
-            await transcriptStore.ReplaceAsync(run.Session, liveSegments, cancellationToken);
+            await ReplaceTranscriptSegmentsAsync(run, liveSegments, cancellationToken);
             return;
         }
 
@@ -1040,7 +1078,7 @@ public sealed class MeetingRecordingCoordinator
             finishedSpeakerResult.Segments.Count,
             samples.Count,
             knownSpeakerMappings.Count);
-        await transcriptStore.ReplaceAsync(run.Session, finishedSpeakerResult.Segments, cancellationToken);
+        await ReplaceTranscriptSegmentsAsync(run, finishedSpeakerResult.Segments, cancellationToken);
     }
 
     private async Task<SpeakerIdentificationResult> IdentifyFinishedSpeakersForTranscriptAsync(
@@ -1177,7 +1215,7 @@ public sealed class MeetingRecordingCoordinator
                 run.MeetingNotePath,
                 run.Options,
                 cancellationToken);
-            await transcriptStore.ReplaceAsync(run.Session, result.Segments, cancellationToken);
+            await ReplaceTranscriptSegmentsAsync(run, result.Segments, cancellationToken);
         }
         catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
         {

MeetingAssistant/Recording/VaultTranscriptStore.cs

@@ -35,14 +35,14 @@ public sealed class VaultTranscriptStore : ITranscriptStore
         return new TranscriptSession(path);
     }
 
-    public Task AppendAsync(TranscriptSession session, TranscriptionSegment segment, CancellationToken cancellationToken)
+    public Task AppendLineAsync(TranscriptSession session, string line, CancellationToken cancellationToken)
     {
-        return AppendToBodyAsync(session.TranscriptPath, FormatSegment(segment), cancellationToken);
+        return AppendToBodyAsync(session.TranscriptPath, line + Environment.NewLine, cancellationToken);
     }
 
-    public Task ReplaceAsync(
+    public Task ReplaceLinesAsync(
         TranscriptSession session,
-        IReadOnlyList<TranscriptionSegment> replacementSegments,
+        IReadOnlyList<string> replacementLines,
         CancellationToken cancellationToken)
     {
         var existing = File.Exists(session.TranscriptPath)
@@ -52,7 +52,7 @@ public sealed class VaultTranscriptStore : ITranscriptStore
         var body = "# Meeting Transcript"
             + Environment.NewLine
             + Environment.NewLine
-            + string.Concat(replacementSegments.Select(FormatSegment));
+            + string.Concat(replacementLines.Select(line => line + Environment.NewLine));
         var content = string.IsNullOrWhiteSpace(frontmatter)
             ? body
             : "---" + Environment.NewLine + frontmatter + Environment.NewLine + "---" + Environment.NewLine + Environment.NewLine + body;
@@ -80,12 +80,6 @@ public sealed class VaultTranscriptStore : ITranscriptStore
             cancellationToken);
     }
 
-    private static string FormatSegment(TranscriptionSegment segment)
-    {
-        var speaker = string.IsNullOrWhiteSpace(segment.Speaker) ? "Unknown" : segment.Speaker;
-        return $"[{segment.Start:hh\\:mm\\:ss}] {speaker}: {segment.Text}{Environment.NewLine}";
-    }
-
     private static async Task AppendToBodyAsync(
         string path,
         string text,

MeetingAssistant/Workflow/MeetingWorkflowEngine.cs

@@ -12,6 +12,11 @@ public interface IMeetingWorkflowEngine
         MeetingWorkflowEvent workflowEvent,
         MeetingAssistantOptions options,
         CancellationToken cancellationToken);
+
+    Task<string> TransformTranscriptLineAsync(
+        MeetingWorkflowEvent workflowEvent,
+        MeetingAssistantOptions options,
+        CancellationToken cancellationToken);
 }
 
 public sealed class NoopMeetingWorkflowEngine : IMeetingWorkflowEngine
@@ -25,6 +30,14 @@ public sealed class NoopMeetingWorkflowEngine : IMeetingWorkflowEngine
     {
         return Task.CompletedTask;
     }
+
+    public Task<string> TransformTranscriptLineAsync(
+        MeetingWorkflowEvent workflowEvent,
+        MeetingAssistantOptions options,
+        CancellationToken cancellationToken)
+    {
+        return Task.FromResult(workflowEvent.TranscriptLineText ?? "");
+    }
 }
 
 public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
@@ -39,7 +52,9 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
         "event.type",
         "state.from",
         "state.to",
-        "speaker.name"
+        "speaker.name",
+        "transcript.line",
+        "transcript.speaker"
     ];
 
     private readonly IMeetingWorkflowRulesProvider rulesProvider;
@@ -64,11 +79,35 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
         MeetingWorkflowEvent workflowEvent,
         MeetingAssistantOptions options,
         CancellationToken cancellationToken)
+    {
+        _ = await RunCoreAsync(workflowEvent, options, cancellationToken);
+    }
+
+    public async Task<string> TransformTranscriptLineAsync(
+        MeetingWorkflowEvent workflowEvent,
+        MeetingAssistantOptions options,
+        CancellationToken cancellationToken)
+    {
+        if (workflowEvent.Type != MeetingWorkflowEventType.TranscriptLine)
+        {
+            throw new ArgumentException("Workflow event must be a transcript line event.", nameof(workflowEvent));
+        }
+
+        return await RunCoreAsync(workflowEvent, options, cancellationToken)
+            ?? workflowEvent.TranscriptLineText
+            ?? "";
+    }
+
+    private async Task<string?> RunCoreAsync(
+        MeetingWorkflowEvent workflowEvent,
+        MeetingAssistantOptions options,
+        CancellationToken cancellationToken)
     {
         var rules = await rulesProvider.GetRulesAsync(options, cancellationToken);
+        var context = new MeetingWorkflowExecutionContext(workflowEvent);
         if (rules.Count == 0)
         {
-            return;
+            return context.TranscriptLine;
         }
 
         var meeting = await meetingNoteStore.ReadAsync(
@@ -79,7 +118,7 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
         foreach (var rule in rules)
         {
             if (!MatchesTrigger(rule, workflowEvent) ||
-                !EvaluateConditions(rule.If, meeting, workflowEvent))
+                !EvaluateConditions(rule.If, meeting, context))
             {
                 continue;
             }
@@ -88,16 +127,16 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
                 "Applying meeting workflow rule {RuleName} for event {EventType}",
                 rule.Name,
                 workflowEvent.Type);
-            var model = CreateTemplateModel(meeting, workflowEvent);
+            var model = CreateTemplateModel(meeting, context);
             foreach (var step in rule.Steps)
             {
                 noteChanged |= await ApplyStepAsync(
                     step,
                     meeting,
-                    workflowEvent,
+                    context,
                     model,
                     cancellationToken);
-                model = CreateTemplateModel(meeting, workflowEvent);
+                model = CreateTemplateModel(meeting, context);
             }
         }
 
@@ -109,6 +148,8 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
                 saved,
                 cancellationToken);
         }
+
+        return context.TranscriptLine;
     }
 
     private static bool MatchesTrigger(
@@ -151,41 +192,51 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
                         StringComparison.OrdinalIgnoreCase));
         }
 
+        if (trigger.TranscriptLine is not null)
+        {
+            return workflowEvent.Type == MeetingWorkflowEventType.TranscriptLine &&
+                (string.IsNullOrWhiteSpace(trigger.TranscriptLine.Speaker) ||
+                    string.Equals(
+                        trigger.TranscriptLine.Speaker.Trim(),
+                        workflowEvent.SpeakerName,
+                        StringComparison.OrdinalIgnoreCase));
+        }
+
         return false;
     }
 
     private bool EvaluateConditions(
         IReadOnlyList<MeetingWorkflowCondition> conditions,
         MeetingNote meeting,
-        MeetingWorkflowEvent workflowEvent)
+        MeetingWorkflowExecutionContext context)
     {
         return conditions.Count == 0 ||
-            conditions.All(condition => EvaluateCondition(condition, meeting, workflowEvent));
+            conditions.All(condition => EvaluateCondition(condition, meeting, context));
     }
 
     private bool EvaluateCondition(
         MeetingWorkflowCondition condition,
         MeetingNote meeting,
-        MeetingWorkflowEvent workflowEvent)
+        MeetingWorkflowExecutionContext context)
     {
         if (!string.IsNullOrWhiteSpace(condition.Condition))
         {
-            return EvaluateExpression(condition.Condition, meeting, workflowEvent);
+            return EvaluateExpression(condition.Condition, meeting, context);
         }
 
         if (condition.And is { Count: > 0 })
         {
-            return condition.And.All(child => EvaluateCondition(child, meeting, workflowEvent));
+            return condition.And.All(child => EvaluateCondition(child, meeting, context));
         }
 
         if (condition.Or is { Count: > 0 })
         {
-            return condition.Or.Any(child => EvaluateCondition(child, meeting, workflowEvent));
+            return condition.Or.Any(child => EvaluateCondition(child, meeting, context));
         }
 
         if (condition.Not is not null)
         {
-            return !EvaluateCondition(condition.Not, meeting, workflowEvent);
+            return !EvaluateCondition(condition.Not, meeting, context);
         }
 
         return true;
@@ -194,10 +245,10 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
     private bool EvaluateExpression(
         string expressionText,
         MeetingNote meeting,
-        MeetingWorkflowEvent workflowEvent)
+        MeetingWorkflowExecutionContext context)
     {
         var expression = new Expression(PrepareExpression(expressionText));
-        foreach (var (name, value) in BuildParameters(meeting, workflowEvent))
+        foreach (var (name, value) in BuildParameters(meeting, context))
         {
             expression.Parameters[name] = value;
         }
@@ -219,7 +270,7 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
     private async Task<bool> ApplyStepAsync(
         MeetingWorkflowStep step,
         MeetingNote meeting,
-        MeetingWorkflowEvent workflowEvent,
+        MeetingWorkflowExecutionContext context,
         MeetingWorkflowTemplateModel model,
         CancellationToken cancellationToken)
     {
@@ -232,14 +283,17 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
                 return RemoveValue(meeting.Frontmatter.Attendees, value);
             case "add_project":
                 return AddUnique(meeting.Frontmatter.Projects, value, static project => project.Trim());
-            case "set_property":
-                return SetProperty(meeting, step.Property ?? step.Name, value);
             case "add_context":
                 await meetingArtifactStore.AppendAssistantContextAsync(
-                    workflowEvent.Artifacts,
+                    context.Event.Artifacts,
                     value,
                     cancellationToken);
                 return false;
+            case "set_property" when IsTranscriptLineProperty(step.Property ?? step.Name):
+                SetTranscriptLine(context, value);
+                return false;
+            case "set_property":
+                return SetProperty(meeting, step.Property ?? step.Name, value);
             default:
                 throw new InvalidOperationException($"Unknown meeting workflow step '{step.Uses}'.");
         }
@@ -272,6 +326,28 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
         throw new InvalidOperationException($"Unsupported meeting workflow property '{property}'.");
     }
 
+    private static void SetTranscriptLine(
+        MeetingWorkflowExecutionContext context,
+        string value)
+    {
+        if (context.Event.Type != MeetingWorkflowEventType.TranscriptLine)
+        {
+            throw new InvalidOperationException("The transcript.line property can only be set during transcript_line events.");
+        }
+
+        if (string.Equals(context.TranscriptLine, value, StringComparison.Ordinal))
+        {
+            return;
+        }
+
+        context.TranscriptLine = value;
+    }
+
+    private static bool IsTranscriptLineProperty(string? property)
+    {
+        return string.Equals(property?.Trim(), "transcript.line", StringComparison.OrdinalIgnoreCase);
+    }
+
     private static bool AddUnique(
         List<string> values,
         string value,
@@ -338,8 +414,9 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
 
     private static IReadOnlyDictionary<string, object?> BuildParameters(
         MeetingNote meeting,
-        MeetingWorkflowEvent workflowEvent)
+        MeetingWorkflowExecutionContext context)
     {
+        var workflowEvent = context.Event;
         return new Dictionary<string, object?>(StringComparer.OrdinalIgnoreCase)
         {
             ["meeting.attendees.count"] = meeting.Frontmatter.Attendees.Count,
@@ -350,14 +427,17 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
             ["event.type"] = workflowEvent.Type.ToString(),
             ["state.from"] = workflowEvent.FromState is { } from ? MeetingWorkflowStateNames.ToRuleName(from) : "",
             ["state.to"] = workflowEvent.ToState is { } to ? MeetingWorkflowStateNames.ToRuleName(to) : "",
-            ["speaker.name"] = workflowEvent.SpeakerName
+            ["speaker.name"] = workflowEvent.SpeakerName,
+            ["transcript.line"] = context.TranscriptLine ?? "",
+            ["transcript.speaker"] = workflowEvent.SpeakerName ?? ""
         };
     }
 
     private static MeetingWorkflowTemplateModel CreateTemplateModel(
         MeetingNote meeting,
-        MeetingWorkflowEvent workflowEvent)
+        MeetingWorkflowExecutionContext context)
     {
+        var workflowEvent = context.Event;
         return new MeetingWorkflowTemplateModel(
             new MeetingWorkflowMeetingModel(
                 meeting.Frontmatter.Title,
@@ -370,6 +450,22 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
                 workflowEvent.ToState is { } to ? MeetingWorkflowStateNames.ToRuleName(to) : null),
             string.IsNullOrWhiteSpace(workflowEvent.SpeakerName)
                 ? null
-                : new MeetingWorkflowSpeakerModel(workflowEvent.SpeakerName));
+                : new MeetingWorkflowSpeakerModel(workflowEvent.SpeakerName),
+            new MeetingWorkflowTranscriptModel(
+                context.TranscriptLine ?? "",
+                workflowEvent.SpeakerName ?? ""));
+    }
+
+    private sealed class MeetingWorkflowExecutionContext
+    {
+        public MeetingWorkflowExecutionContext(MeetingWorkflowEvent workflowEvent)
+        {
+            Event = workflowEvent;
+            TranscriptLine = workflowEvent.TranscriptLineText;
+        }
+
+        public MeetingWorkflowEvent Event { get; }
+
+        public string? TranscriptLine { get; set; }
     }
 }

MeetingAssistant/Workflow/MeetingWorkflowEvent.cs

@@ -6,7 +6,8 @@ public enum MeetingWorkflowEventType
 {
     Created,
     StateTransition,
-    SpeakerIdentified
+    SpeakerIdentified,
+    TranscriptLine
 }
 
 public sealed record MeetingWorkflowEvent(
@@ -14,7 +15,8 @@ public sealed record MeetingWorkflowEvent(
     MeetingSessionArtifacts Artifacts,
     AssistantContextState? FromState = null,
     AssistantContextState? ToState = null,
-    string? SpeakerName = null)
+    string? SpeakerName = null,
+    string? TranscriptLineText = null)
 {
     public static MeetingWorkflowEvent Created(MeetingSessionArtifacts artifacts)
     {
@@ -35,4 +37,16 @@ public sealed record MeetingWorkflowEvent(
     {
         return new MeetingWorkflowEvent(MeetingWorkflowEventType.SpeakerIdentified, artifacts, SpeakerName: speakerName);
     }
+
+    public static MeetingWorkflowEvent TranscriptLine(
+        MeetingSessionArtifacts artifacts,
+        string line,
+        string speakerName)
+    {
+        return new MeetingWorkflowEvent(
+            MeetingWorkflowEventType.TranscriptLine,
+            artifacts,
+            SpeakerName: speakerName,
+            TranscriptLineText: line);
+    }
 }

MeetingAssistant/Workflow/MeetingWorkflowModels.cs

@@ -34,6 +34,9 @@ public sealed class MeetingWorkflowTrigger
 
     [YamlMember(Alias = "speaker_identified")]
     public MeetingWorkflowSpeakerIdentifiedTrigger? SpeakerIdentified { get; set; }
+
+    [YamlMember(Alias = "transcript_line")]
+    public MeetingWorkflowTranscriptLineTrigger? TranscriptLine { get; set; }
 }
 
 public sealed class MeetingWorkflowStateTransitionTrigger
@@ -51,6 +54,12 @@ public sealed class MeetingWorkflowSpeakerIdentifiedTrigger
     public string? Name { get; set; }
 }
 
+public sealed class MeetingWorkflowTranscriptLineTrigger
+{
+    [YamlMember(Alias = "speaker")]
+    public string? Speaker { get; set; }
+}
+
 public sealed class MeetingWorkflowCondition
 {
     [YamlMember(Alias = "condition")]
@@ -84,7 +93,8 @@ public sealed class MeetingWorkflowStep
 public sealed record MeetingWorkflowTemplateModel(
     MeetingWorkflowMeetingModel Meeting,
     MeetingWorkflowEventModel Event,
-    MeetingWorkflowSpeakerModel? Speaker);
+    MeetingWorkflowSpeakerModel? Speaker,
+    MeetingWorkflowTranscriptModel? Transcript);
 
 public sealed record MeetingWorkflowMeetingModel(
     string Title,
@@ -99,6 +109,8 @@ public sealed record MeetingWorkflowEventModel(
 
 public sealed record MeetingWorkflowSpeakerModel(string Name);
 
+public sealed record MeetingWorkflowTranscriptModel(string Line, string Speaker);
+
 internal static class MeetingWorkflowStateNames
 {
     public static string ToRuleName(AssistantContextState state)

MeetingAssistant/Workflow/MeetingWorkflowRulesValidator.cs

@@ -4,11 +4,11 @@ namespace MeetingAssistant.Workflow;
 
 internal static class MeetingWorkflowRulesValidator
 {
-    private static readonly string[] SupportedTriggerKeys = ["created", "state_transition", "speaker_identified"];
+    private static readonly string[] SupportedTriggerKeys = ["created", "state_transition", "speaker_identified", "transcript_line"];
     private static readonly string[] SupportedConditionKeys = ["condition", "and", "or", "not"];
     private static readonly string[] SupportedStepUses =
         ["add_attendee", "remove_attendee", "add_project", "set_property", "add_context"];
-    private static readonly string[] SupportedSetPropertyNames = ["title", "meeting.title"];
+    private static readonly string[] SupportedSetPropertyNames = ["title", "meeting.title", "transcript.line"];
 
     public static async Task<IReadOnlyList<string>> ValidateAsync(MeetingWorkflowRulesFile rulesFile)
     {
@@ -43,6 +43,7 @@ internal static class MeetingWorkflowRulesValidator
             {
                 await ValidateStepAsync(
                     rule.Steps[stepIndex],
+                    rule,
                     ruleName,
                     stepIndex,
                     errors,
@@ -63,7 +64,8 @@ internal static class MeetingWorkflowRulesValidator
         var configuredCount = CountConfigured(
             trigger.Created is not null,
             trigger.StateTransition is not null,
-            trigger.SpeakerIdentified is not null);
+            trigger.SpeakerIdentified is not null,
+            trigger.TranscriptLine is not null);
         if (configuredCount == 0)
         {
             errors.Add($"{ruleName} on[{triggerIndex + 1}] must contain one supported trigger: {JoinAllowed(SupportedTriggerKeys)}.");
@@ -120,6 +122,7 @@ internal static class MeetingWorkflowRulesValidator
 
     private static async Task ValidateStepAsync(
         MeetingWorkflowStep step,
+        MeetingWorkflowRule rule,
         string ruleName,
         int stepIndex,
         List<string> errors,
@@ -151,6 +154,11 @@ internal static class MeetingWorkflowRulesValidator
             {
                 errors.Add($"{stepPath} uses unsupported property '{property}'. Supported properties: {JoinAllowed(SupportedSetPropertyNames)}.");
             }
+            else if (string.Equals(property.Trim(), "transcript.line", StringComparison.OrdinalIgnoreCase) &&
+                !HasTranscriptLineTrigger(rule))
+            {
+                errors.Add($"{stepPath} can set 'transcript.line' only on rules with a transcript_line trigger.");
+            }
         }
 
         if (step.Value is { } value &&
@@ -174,6 +182,11 @@ internal static class MeetingWorkflowRulesValidator
             : $"rule '{rule.Name}'";
     }
 
+    private static bool HasTranscriptLineTrigger(MeetingWorkflowRule rule)
+    {
+        return rule.On.Any(static trigger => trigger.TranscriptLine is not null);
+    }
+
     private static int CountConfigured(params bool[] values)
     {
         return values.Count(static value => value);
@@ -196,7 +209,10 @@ internal static class MeetingWorkflowRulesValidator
                 MeetingWorkflowEventType.StateTransition.ToString(),
                 MeetingWorkflowStateNames.ToRuleName(AssistantContextState.CollectingMetadata),
                 MeetingWorkflowStateNames.ToRuleName(AssistantContextState.Transcribing)),
-            new MeetingWorkflowSpeakerModel("Ada Lovelace"));
+            new MeetingWorkflowSpeakerModel("Ada Lovelace"),
+            new MeetingWorkflowTranscriptModel(
+                "[00:00:01] Ada Lovelace: Validation line.",
+                "Ada Lovelace"));
     }
 
     private static string FormatRazorValidationMessage(Exception exception)