diff --git a/src/ScadaLink.Commons/Interfaces/Transport/IAuditCorrelationContext.cs b/src/ScadaLink.Commons/Interfaces/Transport/IAuditCorrelationContext.cs
new file mode 100644
index 0000000..f042822
--- /dev/null
+++ b/src/ScadaLink.Commons/Interfaces/Transport/IAuditCorrelationContext.cs
@@ -0,0 +1,11 @@
+namespace ScadaLink.Commons.Interfaces.Transport;
+
+/// <summary>
+/// Scoped service the bundle importer sets to thread a BundleImportId through to
+/// the audit log entries emitted by the audited repository methods invoked during
+/// ApplyAsync. AuditService reads this and stamps every AuditLogEntry it writes.
+/// </summary>
+public interface IAuditCorrelationContext
+{
+    Guid? BundleImportId { get; set; }
+}
diff --git a/src/ScadaLink.Commons/Interfaces/Transport/IBundleExporter.cs b/src/ScadaLink.Commons/Interfaces/Transport/IBundleExporter.cs
new file mode 100644
index 0000000..e5b0684
--- /dev/null
+++ b/src/ScadaLink.Commons/Interfaces/Transport/IBundleExporter.cs
@@ -0,0 +1,13 @@
+using ScadaLink.Commons.Types.Transport;
+
+namespace ScadaLink.Commons.Interfaces.Transport;
+
+public interface IBundleExporter
+{
+    Task<Stream> ExportAsync(
+        ExportSelection selection,
+        string user,
+        string sourceEnvironment,
+        string? passphrase,
+        CancellationToken cancellationToken = default);
+}
diff --git a/src/ScadaLink.Commons/Interfaces/Transport/IBundleImporter.cs b/src/ScadaLink.Commons/Interfaces/Transport/IBundleImporter.cs
new file mode 100644
index 0000000..d259d39
--- /dev/null
+++ b/src/ScadaLink.Commons/Interfaces/Transport/IBundleImporter.cs
@@ -0,0 +1,14 @@
+using ScadaLink.Commons.Types.Transport;
+
+namespace ScadaLink.Commons.Interfaces.Transport;
+
+public interface IBundleImporter
+{
+    Task<BundleSession> LoadAsync(Stream bundleStream, string? passphrase, CancellationToken ct = default);
+    Task<ImportPreview> PreviewAsync(Guid sessionId, CancellationToken ct = default);
+    Task<ImportResult> ApplyAsync(
+        Guid sessionId,
+        IReadOnlyList<ImportResolution> resolutions,
+        string user,
+        CancellationToken ct = default);
+}
diff --git a/src/ScadaLink.Commons/Interfaces/Transport/IBundleSessionStore.cs b/src/ScadaLink.Commons/Interfaces/Transport/IBundleSessionStore.cs
new file mode 100644
index 0000000..0f8a178
--- /dev/null
+++ b/src/ScadaLink.Commons/Interfaces/Transport/IBundleSessionStore.cs
@@ -0,0 +1,11 @@
+using ScadaLink.Commons.Types.Transport;
+
+namespace ScadaLink.Commons.Interfaces.Transport;
+
+public interface IBundleSessionStore
+{
+    BundleSession Open(BundleSession session);
+    BundleSession? Get(Guid sessionId);
+    void Remove(Guid sessionId);
+    void EvictExpired();
+}
diff --git a/src/ScadaLink.Commons/Types/Transport/BundleSession.cs b/src/ScadaLink.Commons/Types/Transport/BundleSession.cs
new file mode 100644
index 0000000..b495c0e
--- /dev/null
+++ b/src/ScadaLink.Commons/Types/Transport/BundleSession.cs
@@ -0,0 +1,11 @@
+namespace ScadaLink.Commons.Types.Transport;
+
+public sealed class BundleSession
+{
+    public Guid SessionId { get; init; }
+    public BundleManifest Manifest { get; init; } = null!;
+    public byte[] DecryptedContent { get; init; } = Array.Empty<byte>();
+    public DateTimeOffset ExpiresAt { get; init; }
+    public int FailedUnlockAttempts { get; set; }
+    public bool Locked => FailedUnlockAttempts >= 3;
+}
diff --git a/src/ScadaLink.Commons/Types/Transport/ExportSelection.cs b/src/ScadaLink.Commons/Types/Transport/ExportSelection.cs
new file mode 100644
index 0000000..0c7ce1b
--- /dev/null
+++ b/src/ScadaLink.Commons/Types/Transport/ExportSelection.cs
@@ -0,0 +1,12 @@
+namespace ScadaLink.Commons.Types.Transport;
+
+public sealed record ExportSelection(
+    IReadOnlyList<int> TemplateIds,
+    IReadOnlyList<int> SharedScriptIds,
+    IReadOnlyList<int> ExternalSystemIds,
+    IReadOnlyList<int> DatabaseConnectionIds,
+    IReadOnlyList<int> NotificationListIds,
+    IReadOnlyList<int> SmtpConfigurationIds,
+    IReadOnlyList<int> ApiKeyIds,
+    IReadOnlyList<int> ApiMethodIds,
+    bool IncludeDependencies);
diff --git a/src/ScadaLink.Commons/Types/Transport/ImportPreview.cs b/src/ScadaLink.Commons/Types/Transport/ImportPreview.cs
new file mode 100644
index 0000000..1ee54b6
--- /dev/null
+++ b/src/ScadaLink.Commons/Types/Transport/ImportPreview.cs
@@ -0,0 +1,16 @@
+namespace ScadaLink.Commons.Types.Transport;
+
+public enum ConflictKind { Identical, Modified, New, Blocker }
+
+public sealed record ImportPreviewItem(
+    string EntityType,
+    string Name,
+    int? ExistingVersion,
+    int? IncomingVersion,
+    ConflictKind Kind,
+    string? FieldDiffJson,
+    string? BlockerReason);
+
+public sealed record ImportPreview(
+    Guid SessionId,
+    IReadOnlyList<ImportPreviewItem> Items);
diff --git a/src/ScadaLink.Commons/Types/Transport/ImportResolution.cs b/src/ScadaLink.Commons/Types/Transport/ImportResolution.cs
new file mode 100644
index 0000000..5d3958c
--- /dev/null
+++ b/src/ScadaLink.Commons/Types/Transport/ImportResolution.cs
@@ -0,0 +1,9 @@
+namespace ScadaLink.Commons.Types.Transport;
+
+public enum ResolutionAction { Add, Overwrite, Skip, Rename }
+
+public sealed record ImportResolution(
+    string EntityType,
+    string Name,
+    ResolutionAction Action,
+    string? RenameTo);
diff --git a/src/ScadaLink.Commons/Types/Transport/ImportResult.cs b/src/ScadaLink.Commons/Types/Transport/ImportResult.cs
new file mode 100644
index 0000000..34db172
--- /dev/null
+++ b/src/ScadaLink.Commons/Types/Transport/ImportResult.cs
@@ -0,0 +1,10 @@
+namespace ScadaLink.Commons.Types.Transport;
+
+public sealed record ImportResult(
+    Guid BundleImportId,
+    int Added,
+    int Overwritten,
+    int Skipped,
+    int Renamed,
+    IReadOnlyList<int> StaleInstanceIds,
+    string AuditEventCorrelation);