diff --git a/README.md b/README.md
index 724878b..43c13ae 100644
--- a/README.md
+++ b/README.md
@@ -53,6 +53,8 @@ SQLite default tersimpan di `./data/booster-role.sqlite`.
 bun run dev
 ```
 
+Saat startup, bot otomatis register slash command ke guild dari `DISCORD_GUILD_ID`. Pastikan bot di-invite dengan scope `applications.commands`.
+
 ## Testing
 
 ```bash
diff --git a/src/discord/registerCommands.test.ts b/src/discord/registerCommands.test.ts
new file mode 100644
index 0000000..f018652
--- /dev/null
+++ b/src/discord/registerCommands.test.ts
@@ -0,0 +1,26 @@
+import { describe, expect, test } from "bun:test";
+import { registerGuildCommands, type DiscordRestClient } from "./registerCommands";
+
+class FakeRestClient implements DiscordRestClient {
+  route: string | null = null;
+  body: unknown = null;
+
+  async put(route: string, input: { body: unknown }): Promise<unknown> {
+    this.route = route;
+    this.body = input.body;
+    return null;
+  }
+}
+
+describe("registerGuildCommands", () => {
+  test("registers booster role command to the configured guild", async () => {
+    const rest = new FakeRestClient();
+
+    await registerGuildCommands(rest, { clientId: "client", guildId: "guild" });
+
+    expect(rest.route).toBe("/applications/client/guilds/guild/commands");
+    expect(rest.body).toEqual([
+      expect.objectContaining({ name: "booster-role", description: "Manage your cosmetic booster role" })
+    ]);
+  });
+});
diff --git a/src/discord/registerCommands.ts b/src/discord/registerCommands.ts
new file mode 100644
index 0000000..480b716
--- /dev/null
+++ b/src/discord/registerCommands.ts
@@ -0,0 +1,22 @@
+import { REST, Routes } from "discord.js";
+import { boosterRoleCommand } from "./commands/booster-role";
+
+export type DiscordRestClient = {
+  put(route: string, input: { body: unknown }): Promise<unknown>;
+};
+
+export type RegisterCommandsConfig = {
+  clientId: string;
+  guildId: string;
+};
+
+export async function registerGuildCommands(rest: DiscordRestClient, config: RegisterCommandsConfig): Promise<void> {
+  await rest.put(Routes.applicationGuildCommands(config.clientId, config.guildId), {
+    body: [boosterRoleCommand.toJSON()]
+  });
+}
+
+export async function registerGuildCommandsWithToken(token: string, config: RegisterCommandsConfig): Promise<void> {
+  const rest = new REST({ version: "10" }).setToken(token);
+  await registerGuildCommands(rest, config);
+}
diff --git a/src/index.ts b/src/index.ts
index a6b3c84..a15298f 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,10 +1,16 @@
 import { loadConfig } from "./config";
 import { createDiscordClient } from "./discord/client";
+import { registerGuildCommandsWithToken } from "./discord/registerCommands";
 
 const config = loadConfig();
+await registerGuildCommandsWithToken(config.discordToken, {
+  clientId: config.discordClientId,
+  guildId: config.discordGuildId
+});
+
 const client = createDiscordClient();
 
-client.once("ready", () => {
+client.once("clientReady", () => {
   console.log(`Logged in as ${client.user?.tag ?? "unknown bot"}`);
 });