diff --git a/src/dotnet/QuantEngine.Application/Services/JsonSeedIngestionService.cs b/src/dotnet/QuantEngine.Application/Services/JsonSeedIngestionService.cs
new file mode 100644
index 00000000..f3c65e94
--- /dev/null
+++ b/src/dotnet/QuantEngine.Application/Services/JsonSeedIngestionService.cs
@@ -0,0 +1,69 @@
+using System.Text.Json;
+using QuantEngine.Core.Interfaces;
+
+namespace QuantEngine.Application.Services;
+
+/// <summary>
+/// JSON-first seed ingestion path. XLSX conversion remains an external
+/// preparation step; the runtime application only reads canonical JSON and
+/// persists normalized snapshots to PostgreSQL.
+/// </summary>
+public sealed class JsonSeedIngestionService
+{
+    private readonly GatherTradingDataParser _parser;
+    private readonly ICollectionRepository _repository;
+    private readonly ILogger<JsonSeedIngestionService> _logger;
+
+    public JsonSeedIngestionService(
+        GatherTradingDataParser parser,
+        ICollectionRepository repository,
+        ILogger<JsonSeedIngestionService> logger)
+    {
+        _parser = parser;
+        _repository = repository;
+        _logger = logger;
+    }
+
+    public async Task<CollectionRunResult> IngestAsync(string jsonPath, string runId)
+    {
+        var startedAt = DateTimeOffset.UtcNow;
+        var rows = _parser.ParseGatherTradingData(jsonPath);
+        await _repository.SaveRunAsync(new CollectionRunRecord(
+            runId, "RUNNING", startedAt.ToString("O"), null, rows.Count, 0));
+
+        var errors = 0;
+        foreach (var row in rows)
+        {
+            if (!row.TryGetValue("Ticker", out var tickerValue) || string.IsNullOrWhiteSpace(tickerValue?.ToString()))
+            {
+                errors++;
+                continue;
+            }
+
+            var ticker = tickerValue.ToString()!;
+            await _repository.SaveSnapshotAsync(new CollectionSnapshotRecord(
+                runId,
+                "data_feed",
+                ticker,
+                "json_seed",
+                JsonSerializer.Serialize(row),
+                startedAt.ToString("O")));
+        }
+
+        var finishedAt = DateTimeOffset.UtcNow;
+        var status = rows.Count > 0 && errors == 0 ? "COMPLETED" : "COMPLETED_WITH_ERRORS";
+        await _repository.UpdateRunStatusAsync(runId, status, finishedAt.ToString("O"), rows.Count - errors, errors);
+        _logger.LogInformation("JSON seed ingestion {RunId} completed: {Snapshots} snapshots, {Errors} errors", runId, rows.Count - errors, errors);
+
+        return new CollectionRunResult
+        {
+            RunId = runId,
+            Status = status,
+            StartedAt = startedAt.ToString("O"),
+            FinishedAt = finishedAt.ToString("O"),
+            SuccessCount = rows.Count - errors,
+            ErrorCount = errors,
+            Rows = rows
+        };
+    }
+}
diff --git a/src/dotnet/QuantEngine.Web/Program.cs b/src/dotnet/QuantEngine.Web/Program.cs
index ec2b9ce7..77b95202 100644
--- a/src/dotnet/QuantEngine.Web/Program.cs
+++ b/src/dotnet/QuantEngine.Web/Program.cs
@@ -100,6 +100,8 @@ try
     builder.Services.AddScoped<ILearningDatasetReader, LearningDatasetReader>();
     builder.Services.AddScoped<DecisionLearningService>();
     builder.Services.AddScoped<LearningDatasetService>();
+    builder.Services.AddSingleton<GatherTradingDataParser>();
+    builder.Services.AddScoped<JsonSeedIngestionService>();
     builder.Services.AddScoped<IPostgresqlHistorySnapshotReader, PostgresqlHistorySnapshotReader>();
     builder.Services.AddScoped<HistoryIngestionService>();
     builder.Services.AddScoped<ICollectionRepository, CollectionRepository>();