diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Browsing/BrowseNode.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Browsing/BrowseNode.cs
new file mode 100644
index 00000000..33dbacac
--- /dev/null
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Browsing/BrowseNode.cs
@@ -0,0 +1,32 @@
+namespace ZB.MOM.WW.OtOpcUa.Commons.Browsing;
+
+/// <summary>One node in a driver-agnostic browse tree.</summary>
+/// <param name="NodeId">Stable identifier passed back to the picker on commit. For OPC UA
+/// this is the <c>nsu=...;...</c> form; for Galaxy this is the <c>tag_name</c>.</param>
+/// <param name="DisplayName">Label shown in the tree.</param>
+/// <param name="Kind">Whether this node terminates the address (Leaf) or has children
+/// (Folder). Galaxy never returns Leaves; only the attribute side-panel terminates.</param>
+/// <param name="HasChildrenHint">When true, the UI renders an expand affordance before
+/// the children have been fetched.</param>
+public sealed record BrowseNode(
+    string NodeId,
+    string DisplayName,
+    BrowseNodeKind Kind,
+    bool HasChildrenHint);
+
+/// <summary>Discriminates terminal vs. expandable nodes for UI rendering.</summary>
+public enum BrowseNodeKind
+{
+    /// <summary>Expandable — has (or may have) children. UI shows expand affordance.</summary>
+    Folder,
+    /// <summary>Terminal — commit on select.</summary>
+    Leaf,
+}
+
+/// <summary>Metadata for an attribute of a Galaxy object (or the equivalent
+/// per-driver concept). Surfaced in the picker's attribute side-panel.</summary>
+public sealed record AttributeInfo(
+    string Name,
+    string DriverDataType,
+    bool   IsArray,
+    string SecurityClass);
diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Browsing/IBrowseSession.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Browsing/IBrowseSession.cs
new file mode 100644
index 00000000..a470b7e2
--- /dev/null
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Browsing/IBrowseSession.cs
@@ -0,0 +1,29 @@
+namespace ZB.MOM.WW.OtOpcUa.Commons.Browsing;
+
+/// <summary>
+///     A live, one-level-at-a-time browse over a remote address space. Owned by the
+///     AdminUI <c>BrowseSessionRegistry</c>; disposed by the registry's TTL reaper or
+///     the picker body on close.
+/// </summary>
+public interface IBrowseSession : IAsyncDisposable
+{
+    /// <summary>Opaque token identifying this session in the registry.</summary>
+    Guid Token { get; }
+
+    /// <summary>Wall-clock time of the most recent successful call. Refreshed on
+    /// <see cref="RootAsync"/>, <see cref="ExpandAsync"/>, and
+    /// <see cref="AttributesAsync"/>; used by the reaper for idle eviction.</summary>
+    DateTime LastUsedUtc { get; }
+
+    /// <summary>Returns the top-level browse nodes.</summary>
+    Task<IReadOnlyList<BrowseNode>> RootAsync(CancellationToken cancellationToken);
+
+    /// <summary>Returns the direct children of the node identified by
+    /// <paramref name="nodeId"/>.</summary>
+    Task<IReadOnlyList<BrowseNode>> ExpandAsync(string nodeId, CancellationToken cancellationToken);
+
+    /// <summary>Returns the attributes of the node identified by <paramref name="nodeId"/>.
+    /// Empty for drivers whose tree is uniform (OPC UA Client). Galaxy uses this to populate
+    /// the attribute side-panel after the user selects an object.</summary>
+    Task<IReadOnlyList<AttributeInfo>> AttributesAsync(string nodeId, CancellationToken cancellationToken);
+}
diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Browsing/IDriverBrowser.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Browsing/IDriverBrowser.cs
new file mode 100644
index 00000000..80f80375
--- /dev/null
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Browsing/IDriverBrowser.cs
@@ -0,0 +1,19 @@
+namespace ZB.MOM.WW.OtOpcUa.Commons.Browsing;
+
+/// <summary>
+///     Per-driver factory that opens an ad-hoc browse session against the configuration
+///     supplied as JSON. Parallels <c>IDriverProbe</c> in the runtime — one implementation
+///     per driver type, registered in AdminUI DI and indexed by <see cref="DriverType"/>.
+/// </summary>
+public interface IDriverBrowser
+{
+    /// <summary>Driver type key, matching the AdminUI's persisted DriverType string
+    /// (e.g. "OpcUaClient", "Galaxy").</summary>
+    string DriverType { get; }
+
+    /// <summary>Opens a browse session against the supplied configuration.</summary>
+    /// <param name="configJson">Driver options serialized as JSON; same shape the runtime
+    /// driver would consume.</param>
+    /// <param name="cancellationToken">Cancellation for the connect phase only.</param>
+    Task<IBrowseSession> OpenAsync(string configJson, CancellationToken cancellationToken);
+}