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OpenAB Gemini

Open Agent Broker — a lightweight Rust harness that bridges Discord to any ACP-compatible coding CLI (Claude Code, Codex, Gemini, Kiro, Cursor) over stdio JSON-RPC. This template deploys the Gemini variant. Source: https://github.com/openabdev/openab

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Deployed23 times
PublisherzeaburZeabur
Created2026-04-20
SourceView Source
Minimum2 Cores4 GB
Recommended4 Cores8 GB
Tags
AIDeveloper ToolsDiscord

Services

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openab

ghcr.io/openabdev/openab-gemini:0.8.3-beta.4

OpenAB Gemini

OpenAB is a lightweight, open-source Rust harness that bridges Discord to any Agent Client Protocol-compatible coding CLI over stdio JSON-RPC.

This template deploys the Gemini variant (openab-gemini) which uses gemini --acp as the agent backend.

Important Notes

  • Image tag: This template uses a pinned version (0.8.3-beta.4). To upgrade, change the image tag in Zeabur Dashboard -> Service -> Settings. Available tags: GitHub Packages.
  • Persistent storage: /home/node is mounted as a persistent volume. Plugins, settings, config, and credentials survive restarts.
  • Config ownership: The container starts as root and switches to node user (uid 1000) before running openab. If you encounter permission issues, restart the service -- ownership is fixed automatically on boot.

Setup

1. Get a Discord Bot Token

  1. Go to https://discord.com/developers/applications and click New Application
  2. Navigate to Bot tab -> click Reset Token -> copy the token
  3. On the same page, scroll down and enable Message Content Intent under Privileged Gateway Intents
  4. Go to OAuth2 -> URL Generator -> check scope bot -> check permissions: Send Messages, Send Messages in Threads, Create Public Threads, Read Message History, Add Reactions, Manage Messages
  5. Copy the generated URL and open it in your browser to invite the bot to your server

2. Authenticate

Quickest: fill in the GEMINI_API_KEY template variable at deploy time and you're done.

Otherwise: after deployment, open Zeabur Dashboard → Service → Exec and run:

runuser -u node -- gemini

Follow the on-screen prompts to pick and complete an auth method. Credentials are saved on the persistent volume; new conversations apply the new auth automatically — no restart needed.

Wiring API keys to the agent: openab spawns the agent with env_clear(), so the GEMINI_API_KEY path requires an env allowlist. After first boot edit /home/node/.config/openab/config.toml and add under [agent]:

[agent]
inherit_env = ["GEMINI_API_KEY", "GOOGLE_API_KEY", "GOOGLE_GENERATIVE_AI_API_KEY"]

Interactive login needs no edit — credentials live in ~/.gemini/.

3. Get Discord Channel IDs

  1. Open Discord -> go to User Settings (gear icon) -> Advanced -> enable Developer Mode
  2. Right-click the channel where you want the bot to respond -> Copy Channel ID
  3. For multiple channels, separate IDs with commas: 123456789012345678,234567890123456789

4. Deploy

Fill in the template variables and click deploy. The service connects to Discord automatically.

Add Messaging Platforms (Telegram / LINE / Feishu / Google Chat / MS Teams)

To bridge Telegram, LINE, Feishu/Lark, Google Chat, or MS Teams, deploy the OpenAB Gateway template into the same Zeabur project. Then add these environment variables to this service:

  • GATEWAY_URL = ws://openab-gateway:8080/ws
  • GATEWAY_PLATFORM = one of telegram, line, feishu, googlechat, teams

Restart the service. The startup script auto-injects the [gateway] block into config.toml.

Usage

  • @mention the bot in an allowed channel to start a conversation
  • OpenAB creates a thread for multi-turn conversations -- no @mention needed for follow-ups
  • Each thread maps to a persistent Gemini session (24h TTL)

Customization

FileDescription
/home/node/.config/openab/config.tomlOpenAB config (sessions, reactions, STT, etc.)

config.toml is created from a built-in template on first boot. After that, edit the file directly -- environment variables are only used for initial setup. To reset to defaults, delete the file and restart: rm /home/node/.config/openab/config.toml

For config options, see the OpenAB documentation.

Webhook / Bot Integration

By default, openab ignores messages from other bots and webhooks. To allow webhook-triggered messages (e.g. automated testing or CI pipelines), add the following to your config.toml:

[discord]
allow_bot_messages = "mentions"

With this setting, openab responds to any bot or webhook message that @mentions it. To restrict to a specific webhook, also add:

trusted_bot_ids = ["YOUR_WEBHOOK_USER_ID"]

The webhook user ID is the numeric ID in the webhook URL: https://discord.com/api/webhooks/<ID>/...

Disabling

Leave Discord Bot Token empty. The service sleeps instead of crashing.