From 21b7f5daa5bd606364281a98ddfb6383ac645d3c Mon Sep 17 00:00:00 2001
From: Masami <masami-agent@users.noreply.github.com>
Date: Tue, 14 Apr 2026 12:22:13 +0000
Subject: [PATCH] fix: improve gateway intents and auth error messages

Catch DisallowedGatewayIntents and InvalidAuthentication errors from
Discord gateway with actionable error messages instead of cryptic
serenity errors.

Add prerequisites section to README documenting required Discord
Developer Portal settings.

Closes #116
---
 README.md   | 13 +++++++++++++
 src/main.rs | 21 ++++++++++++++++++++-
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 71981c70..c705dc48 100644
--- a/README.md
+++ b/README.md
@@ -44,6 +44,19 @@ A lightweight, secure, cloud-native ACP harness that bridges **Discord, Slack**,
 
 ## Quick Start
 
+### Prerequisites
+
+Before running openab, enable these in the [Discord Developer Portal](https://discord.com/developers/applications):
+
+1. **Bot → Privileged Gateway Intents**:
+   - ✅ Message Content Intent
+   - ✅ Server Members Intent
+2. **OAuth2 → URL Generator → Bot Permissions**:
+   - Send Messages, Embed Links, Attach Files
+   - Read Message History, Add Reactions
+
+See [docs/discord.md](docs/discord.md) for a detailed step-by-step guide.
+
 ### 1. Create a Bot
 
 <details>
diff --git a/src/main.rs b/src/main.rs
index 5e94dcdd..6d5c3135 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -16,6 +16,7 @@ mod gateway;
 
 use adapter::AdapterRouter;
 use clap::Parser;
+use serenity::gateway::GatewayError;
 use serenity::prelude::*;
 use std::collections::HashSet;
 use std::path::PathBuf;
@@ -336,7 +337,25 @@ async fn main() -> anyhow::Result<()> {
         });
 
         info!("discord bot running");
-        client.start().await?;
+        match client.start().await {
+            Err(serenity::Error::Gateway(GatewayError::DisallowedGatewayIntents)) => {
+                error!(
+                    "Discord rejected privileged intents. \
+                     Enable MESSAGE CONTENT INTENT at: \
+                     https://discord.com/developers/applications → Bot → Privileged Gateway Intents"
+                );
+                std::process::exit(1);
+            }
+            Err(serenity::Error::Gateway(GatewayError::InvalidAuthentication)) => {
+                error!(
+                    "Discord rejected bot token. \
+                     Verify your bot_token in config.toml is correct and has not been reset."
+                );
+                std::process::exit(1);
+            }
+            Err(e) => return Err(e.into()),
+            Ok(_) => {}
+        }
     } else {
         // No Discord — wait for SIGINT or SIGTERM
         info!("running without discord, press ctrl+c to stop");