diff --git a/rojo-test/serve-test-snapshots/serve_test__empty.snap b/rojo-test/serve-test-snapshots/serve_test__empty.snap
index e768d5fa..e65f8192 100644
--- a/rojo-test/serve-test-snapshots/serve_test__empty.snap
+++ b/rojo-test/serve-test-snapshots/serve_test__empty.snap
@@ -6,3 +6,4 @@ sessionId: "[session id]"
 serverVersion: 0.5.0
 protocolVersion: 3
 expectedPlaceIds: ~
+rootInstanceId: "[root id]"
diff --git a/rojo-test/src/serve_test.rs b/rojo-test/src/serve_test.rs
index 392d6f9f..e8f4cdeb 100644
--- a/rojo-test/src/serve_test.rs
+++ b/rojo-test/src/serve_test.rs
@@ -28,7 +28,8 @@ fn empty() {
         let info = session.wait_to_come_online();
 
         assert_yaml_snapshot!(info, {
-            ".sessionId" => "[session id]"
+            ".sessionId" => "[session id]",
+            ".rootInstanceId" => "[root id]"
         });
     });
 }
diff --git a/src/commands/serve.rs b/src/commands/serve.rs
index 9d6c89d5..55f187da 100644
--- a/src/commands/serve.rs
+++ b/src/commands/serve.rs
@@ -70,7 +70,7 @@ pub fn serve(options: &ServeOptions) -> Result<(), ServeError> {
     let patch_set = compute_patch_set(&snapshot, &tree, root_id);
     apply_patch_set(&mut tree, &patch_set);
 
-    let session = Arc::new(ServeSession::new(maybe_project));
+    let session = Arc::new(ServeSession::new(tree, maybe_project));
     let server = LiveServer::new(session);
 
     server.start(port);
diff --git a/src/imfs/error.rs b/src/imfs/error.rs
index 07c7a8df..0369132e 100644
--- a/src/imfs/error.rs
+++ b/src/imfs/error.rs
@@ -19,19 +19,6 @@ impl<T> FsResultExt<T> for Result<T, FsError> {
     }
 }
 
-// TODO: New error type that contains errors specific to our application,
-// wrapping io::Error either directly or through another error type that has
-// path information.
-//
-// It's possible that we should hoist up the path information one more level, or
-// destructure/restructure information to hoist the path out of FsError and just
-// embed io::Error?
-pub enum ImfsError {
-    NotFound,
-    WrongKind,
-    Io(io::Error),
-}
-
 /// A wrapper around io::Error that also attaches the path associated with the
 /// error.
 #[derive(Debug, Fail)]
diff --git a/src/project.rs b/src/project.rs
index 1b736a63..1869fe31 100644
--- a/src/project.rs
+++ b/src/project.rs
@@ -34,7 +34,7 @@ struct SourceProject {
 
 impl SourceProject {
     /// Consumes the SourceProject and yields a Project, ready for prime-time.
-    pub fn into_project(mut self, project_file_location: &Path) -> Project {
+    pub fn into_project(self, project_file_location: &Path) -> Project {
         let tree = self.tree.into_project_node(project_file_location);
 
         Project {
diff --git a/src/serve_session.rs b/src/serve_session.rs
index 2eb40af8..1396b1de 100644
--- a/src/serve_session.rs
+++ b/src/serve_session.rs
@@ -1,23 +1,29 @@
 use std::collections::HashSet;
 
-use crate::{project::Project, session_id::SessionId};
+use crate::{project::Project, session_id::SessionId, snapshot::RojoTree};
 
 /// Contains all of the state for a Rojo serve session.
 pub struct ServeSession {
     root_project: Option<Project>,
     session_id: SessionId,
+    tree: RojoTree,
 }
 
 impl ServeSession {
-    pub fn new(root_project: Option<Project>) -> ServeSession {
+    pub fn new(tree: RojoTree, root_project: Option<Project>) -> ServeSession {
         let session_id = SessionId::new();
 
         ServeSession {
             session_id,
             root_project,
+            tree,
         }
     }
 
+    pub fn tree(&self) -> &RojoTree {
+        &self.tree
+    }
+
     pub fn session_id(&self) -> SessionId {
         self.session_id
     }
diff --git a/src/snapshot_middleware/lua.rs b/src/snapshot_middleware/lua.rs
index 91b5d77d..1b71416d 100644
--- a/src/snapshot_middleware/lua.rs
+++ b/src/snapshot_middleware/lua.rs
@@ -111,10 +111,12 @@ fn snapshot_init<F: ImfsFetcher>(
     let init_path = folder_entry.path().join(init_name);
 
     if let Some(init_entry) = imfs.get(init_path).with_not_found()? {
-        if let Some(mut dir_snapshot) = SnapshotDir::from_imfs(imfs, folder_entry)? {
+        if let Some(dir_snapshot) = SnapshotDir::from_imfs(imfs, folder_entry)? {
             if let Some(mut init_snapshot) = snapshot_lua_file(imfs, &init_entry)? {
                 init_snapshot.name = dir_snapshot.name;
                 init_snapshot.children = dir_snapshot.children;
+                // TODO: Metadata
+                // TODO: Validate directory class name is "Folder"
 
                 return Ok(Some(init_snapshot));
             }
diff --git a/src/web/api.rs b/src/web/api.rs
index 759b3ea9..03962d03 100644
--- a/src/web/api.rs
+++ b/src/web/api.rs
@@ -53,11 +53,15 @@ impl ApiService {
 
     /// Get a summary of information about the server
     fn handle_api_rojo(&self) -> Response<Body> {
+        let tree = self.serve_session.tree();
+        let root_instance_id = tree.get_root_id();
+
         response_json(&ServerInfoResponse {
             server_version: SERVER_VERSION.to_owned(),
             protocol_version: PROTOCOL_VERSION,
             session_id: self.serve_session.session_id(),
-            expected_place_ids: self.serve_session.serve_place_ids().map(Clone::clone),
+            expected_place_ids: self.serve_session.serve_place_ids().cloned(),
+            root_instance_id,
         })
     }
 
diff --git a/src/web/interface.rs b/src/web/interface.rs
index 1ed2bd94..7f8d5d82 100644
--- a/src/web/interface.rs
+++ b/src/web/interface.rs
@@ -2,6 +2,7 @@
 
 use std::collections::HashSet;
 
+use rbx_dom_weak::RbxId;
 use serde::{Deserialize, Serialize};
 
 use crate::session_id::SessionId;
@@ -20,7 +21,7 @@ pub struct ServerInfoResponse {
     pub server_version: String,
     pub protocol_version: u64,
     pub expected_place_ids: Option<HashSet<u64>>,
-    // pub root_instance_id: RbxId,
+    pub root_instance_id: RbxId,
 }
 
 /// Response body from /api/read/{id}