diff --git a/src/hooks/comment_storage.rs b/src/hooks/comment_storage.rs
new file mode 100644
index 0000000..8bf4a56
--- /dev/null
+++ b/src/hooks/comment_storage.rs
@@ -0,0 +1,188 @@
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+
+const AUTHOR_KEY: &str = "yggdrasil-comment-author";
+const PENDING_KEY: &str = "yggdrasil-pending-comments";
+const TTL_DAYS: i64 = 7;
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct AuthorInfo {
+    pub name: String,
+    pub email: String,
+    #[serde(default)]
+    pub url: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct PendingComment {
+    pub id: i64,
+    pub parent_id: Option<i64>,
+    pub depth: i32,
+    pub author_name: String,
+    pub author_url: Option<String>,
+    pub avatar_url: String,
+    pub content_md: String,
+    pub created_at: String,
+    pub stored_at: String,
+}
+
+type PendingMap = std::collections::HashMap<String, Vec<PendingComment>>;
+
+fn read_storage(key: &str) -> Option<String> {
+    #[cfg(target_arch = "wasm32")]
+    {
+        let window = web_sys::window()?;
+        let storage = window.local_storage().ok()??;
+        storage.get_item(key).ok()?
+    }
+    #[cfg(not(target_arch = "wasm32"))]
+    {
+        None
+    }
+}
+
+fn write_storage(key: &str, value: &str) {
+    #[cfg(target_arch = "wasm32")]
+    {
+        if let Some(window) = web_sys::window() {
+            if let Ok(Some(storage)) = window.local_storage() {
+                let _ = storage.set_item(key, value);
+            }
+        }
+    }
+}
+
+fn now_iso() -> String {
+    Utc::now().to_rfc3339()
+}
+
+fn is_expired(stored_at: &str) -> bool {
+    let Ok(dt) = DateTime::parse_from_rfc3339(stored_at) else {
+        return true;
+    };
+    let Ok(now) = DateTime::parse_from_rfc3339(&now_iso()) else {
+        return false;
+    };
+    (now - dt).num_days() > TTL_DAYS
+}
+
+pub fn save_author(name: &str, email: &str, url: &str) {
+    let info = AuthorInfo {
+        name: name.to_string(),
+        email: email.to_string(),
+        url: url.to_string(),
+    };
+    if let Ok(json) = serde_json::to_string(&info) {
+        write_storage(AUTHOR_KEY, &json);
+    }
+}
+
+pub fn load_author() -> Option<AuthorInfo> {
+    let json = read_storage(AUTHOR_KEY)?;
+    serde_json::from_str(&json).ok()
+}
+
+pub fn save_pending_comment(post_id: i32, comment: PendingComment) {
+    let mut map: PendingMap = load_all_pending();
+    let key = post_id.to_string();
+    let list = map.entry(key).or_default();
+
+    if list.iter().any(|c| c.id == comment.id) {
+        return;
+    }
+    list.push(comment);
+
+    if let Ok(json) = serde_json::to_string(&map) {
+        write_storage(PENDING_KEY, &json);
+    }
+}
+
+pub fn load_pending_comments(post_id: i32) -> Vec<PendingComment> {
+    let mut map = load_all_pending();
+    let key = post_id.to_string();
+
+    let comments = map.remove(&key).unwrap_or_default();
+    let non_expired: Vec<PendingComment> = comments
+        .into_iter()
+        .filter(|c| !is_expired(&c.stored_at))
+        .collect();
+
+    if !non_expired.is_empty() {
+        map.insert(key, non_expired.clone());
+    }
+    if let Ok(json) = serde_json::to_string(&map) {
+        write_storage(PENDING_KEY, &json);
+    }
+
+    non_expired
+}
+
+pub fn remove_pending_ids(post_id: i32, ids: &[i64]) {
+    let mut map = load_all_pending();
+    let key = post_id.to_string();
+
+    let should_remove = if let Some(comments) = map.get_mut(&key) {
+        comments.retain(|c| !ids.contains(&c.id));
+        comments.is_empty()
+    } else {
+        false
+    };
+    if should_remove {
+        map.remove(&key);
+    }
+
+    if let Ok(json) = serde_json::to_string(&map) {
+        write_storage(PENDING_KEY, &json);
+    }
+}
+
+pub fn prune_all_expired() {
+    let mut map = load_all_pending();
+    let mut changed = false;
+
+    let keys: Vec<String> = map.keys().cloned().collect();
+    for key in keys {
+        let should_remove = if let Some(comments) = map.get_mut(&key) {
+            let before = comments.len();
+            comments.retain(|c| !is_expired(&c.stored_at));
+            if comments.len() != before {
+                changed = true;
+            }
+            comments.is_empty()
+        } else {
+            false
+        };
+        if should_remove {
+            map.remove(&key);
+            changed = true;
+        }
+    }
+
+    if changed {
+        if let Ok(json) = serde_json::to_string(&map) {
+            write_storage(PENDING_KEY, &json);
+        }
+    }
+}
+
+fn load_all_pending() -> PendingMap {
+    let json = match read_storage(PENDING_KEY) {
+        Some(j) => j,
+        None => return PendingMap::new(),
+    };
+    serde_json::from_str(&json).unwrap_or_default()
+}
+
+pub fn escape_html(input: &str) -> String {
+    input
+        .replace('&', "&amp;")
+        .replace('<', "&lt;")
+        .replace('>', "&gt;")
+        .replace('"', "&quot;")
+        .replace('\'', "&#39;")
+}
+
+pub fn render_pending_content(md: &str) -> String {
+    let escaped = escape_html(md);
+    escaped.replace('\n', "<br>")
+}
diff --git a/src/hooks/mod.rs b/src/hooks/mod.rs
index 5d29053..247a499 100644
--- a/src/hooks/mod.rs
+++ b/src/hooks/mod.rs
@@ -1 +1,2 @@
 pub mod delayed_loading;
+pub mod comment_storage;