diff --git a/cove-tui/src/chat/tree/blocks.rs b/cove-tui/src/chat/tree/blocks.rs
index 7cd46fd..6b5a221 100644
--- a/cove-tui/src/chat/tree/blocks.rs
+++ b/cove-tui/src/chat/tree/blocks.rs
@@ -1,3 +1,5 @@
+//! Intermediate representation of messages as blocks of lines.
+
 use std::collections::VecDeque;
 
 use chrono::{DateTime, Utc};
diff --git a/cove-tui/src/chat/tree/layout.rs b/cove-tui/src/chat/tree/layout.rs
index 8cc9f81..55b4a84 100644
--- a/cove-tui/src/chat/tree/layout.rs
+++ b/cove-tui/src/chat/tree/layout.rs
@@ -1,3 +1,5 @@
+//! Arranging messages as blocks.
+
 use toss::frame::{Frame, Size};
 
 use crate::chat::Cursor;
diff --git a/cove-tui/src/chat/tree/render.rs b/cove-tui/src/chat/tree/render.rs
index f464ecb..5ce35fa 100644
--- a/cove-tui/src/chat/tree/render.rs
+++ b/cove-tui/src/chat/tree/render.rs
@@ -1,3 +1,5 @@
+//! Rendering blocks to a [`Frame`].
+
 use chrono::{DateTime, Utc};
 use crossterm::style::ContentStyle;
 use toss::frame::{Frame, Pos, Size};
diff --git a/cove-tui/src/chat/tree/util.rs b/cove-tui/src/chat/tree/util.rs
index c028fcb..f1e7482 100644
--- a/cove-tui/src/chat/tree/util.rs
+++ b/cove-tui/src/chat/tree/util.rs
@@ -1,3 +1,5 @@
+//! Constants and helper functions.
+
 use crossterm::style::{ContentStyle, Stylize};
 use toss::frame::Frame;