diff --git a/README.md b/README.md
index fd94106c..9cccbbc9 100644
--- a/README.md
+++ b/README.md
@@ -228,6 +228,7 @@ OmegaBot is online
 │   │   ├── discord
 │   │   │   ├── commandLoader.ts
 │   │   │   ├── commandMeta.ts
+│   │   │   ├── cooldowns.ts
 │   │   │   ├── fetchChannelMessages.ts
 │   │   │   └── interactionHandler.ts
 │   │   ├── faq
diff --git a/src/services/discord/cooldowns.ts b/src/services/discord/cooldowns.ts
new file mode 100644
index 00000000..0e059c08
--- /dev/null
+++ b/src/services/discord/cooldowns.ts
@@ -0,0 +1,41 @@
+// src/services/discord/cooldowns.ts
+
+/**
+ * In-memory cooldown store.
+ *
+ * Key format: `${userId}:${commandName}`
+ * Value: timestamp (ms) when the command can be used again
+ */
+const cooldowns = new Map<string, number>();
+
+function makeKey(userId: string, commandName: string): string {
+  return `${userId}:${commandName}`;
+}
+
+/**
+ * Returns remaining cooldown time in milliseconds.
+ * Returns 0 if no cooldown is active.
+ */
+export function getCooldownRemainingMs(userId: string, commandName: string): number {
+  const key = makeKey(userId, commandName);
+  const expiresAt = cooldowns.get(key);
+
+  if (!expiresAt) return 0;
+
+  const remaining = expiresAt - Date.now();
+  return remaining > 0 ? remaining : 0;
+}
+
+/**
+ * Sets a cooldown for a user + command.
+ */
+export function setCooldown(
+  userId: string,
+  commandName: string,
+  durationMs: number,
+): void {
+  if (durationMs <= 0) return;
+
+  const key = makeKey(userId, commandName);
+  cooldowns.set(key, Date.now() + durationMs);
+}
diff --git a/src/services/discord/interactionHandler.ts b/src/services/discord/interactionHandler.ts
index 0808bd00..75571a4d 100644
--- a/src/services/discord/interactionHandler.ts
+++ b/src/services/discord/interactionHandler.ts
@@ -17,6 +17,23 @@
 import type { Interaction, ChatInputCommandInteraction } from "discord.js";
 import type { CommandClient } from "./commandLoader.js";
 import { logger } from "../../utils/logger.js";
+import { getCooldownRemainingMs, setCooldown } from "./cooldowns.js";
+
+/**
+ * Per-command cooldown durations (ms).
+ *
+ * Keep this list small and focused:
+ * - Only expensive commands should be throttled (LLM calls, external APIs).
+ * - Defaults to 0 (no cooldown) for commands not listed here.
+ *
+ * Adjust as needed.
+ */
+const COOLDOWN_MS: Record<string, number> = {
+  summary: 30_000,
+  // github lookups (example)
+  // gh: 5_000,
+  // pr: 5_000,
+};
 
 /**
  * Handle a single Discord interaction.
@@ -73,6 +90,31 @@ export async function handleInteraction(
     return;
   }
 
+  /**
+   * Cooldowns (per-user, per-command)
+   *
+   * Cooldown is enforced here so every command benefits consistently.
+   * We set cooldown BEFORE execution to prevent spam even if the command fails.
+   */
+  const userId = interaction.user.id;
+  const commandName = interaction.commandName;
+
+  const remainingMs = getCooldownRemainingMs(userId, commandName);
+  if (remainingMs > 0) {
+    const seconds = Math.ceil(remainingMs / 1000);
+
+    await interaction.reply({
+      content: `⏳ That command is on cooldown. Try again in ${seconds}s.`,
+      ephemeral: true,
+    });
+    return;
+  }
+
+  const durationMs = COOLDOWN_MS[commandName] ?? 0;
+  if (durationMs > 0) {
+    setCooldown(userId, commandName, durationMs);
+  }
+
   /**
    * Execute the command safely.
    *