Does Sentō need a pay-per-token API key?

No. Sentō authenticates using the same Claude Code OAuth token you already sign in with on your machine, and that token is tied to your Claude Pro or Max subscription, not to a pay-as-you-go Anthropic Console key. Every message your agent sends counts against your subscription, not a separate metered invoice. If you prefer to run on a pay-per-token API key instead, Sentō supports that too.

How much does it cost to run a Sentō agent 24/7?

Zero extra on top of the Claude subscription you're already paying for. A Pro plan is enough for a daily-driver agent; Max unlocks heavier 24/7 workloads. Sentō also routes everything through Claude Code, which means you get Claude Code's own context and caching optimizations, so the same token goes further than it would through a raw API call. You never see a separate token bill.

How long does setup take?

About five minutes. Run `npx sentoagent init`, answer a few questions about model, channel, and bot token, and the agent launches and comes online on Discord, Telegram, Slack, or iMessage.

What makes Sentō self-healing?

Every agent runs under a Guardian + Watchdog pair. Guardian restarts the agent process if it crashes; Watchdog watches Guardian. If the agent goes down, it's back up before you notice, and you can fix anything right from Discord without SSH'ing in.

Can two Sentō agents talk to each other?

Yes. Sentō is the first framework with built-in, secure agent-to-agent messaging. Every message is HMAC-SHA256 signed, pairing requires mutual consent on both sides, and rate limiting is on by default.

Which messaging platforms are supported?

Discord, Telegram, Slack, and iMessage out of the box. You can run on a VPS, inside Docker, or directly on macOS.

Is Sentō open source?

Yes, MIT licensed. The source lives at github.com/sentoagent/sento and the package at npmjs.com/package/sentoagent.

Discord channel

Discord is the most common channel for Sentō. It's the recommended starting point for new agents.

Create the bot

Go to discord.com/developers/applications
New Application → name it (anything — the actual agent name is set later in sento init)
Bot tab → Reset Token → copy. Save it in your password manager.
Privileged Gateway Intents: enable Message Content Intent and Server Members Intent.
OAuth2 → URL Generator: scope bot, permissions: View Channels, Send Messages, Send Messages in Threads, Read Message History, Attach Files, Add Reactions. Copy the generated URL, open it in your browser, add the bot to your server.

Find your Server ID

Discord → Settings → Advanced → Developer Mode ON
Right-click your server name → Copy Server ID

You'll paste both the token and the server ID during sento init.

Access control

Sentō's Discord plugin honors an access.json file at ~/.claude/channels/discord/access.json:

{
  "dmPolicy": "allowlist",
  "allowFrom": [],
  "groups": {
    "<server-id-or-channel-id>": { "requireMention": false, "allowFrom": [] }
  }
}

dmPolicy: pairing (default — reply to unknown senders with a 5-char code, wait for owner approval), allowlist (only reply to listed user IDs), open, or disabled.
groups: per-server or per-channel policy. requireMention: true means the bot only responds when @mentioned.

Full discussion: Access control concepts.

Common gotchas

Bot shows offline: run sento restart, wait 30 seconds. If still offline, check sento logs -n 50 for auth errors.
"Message Content Intent" error: you didn't enable the intent at the Developer Portal. Go back and toggle it on.
Agent doesn't respond: the bot doesn't have View Channel + Send Messages permission in that specific channel. Right-click channel → Edit Channel → Permissions → add the bot role.

Multi-server + multi-channel

The Discord plugin supports multiple servers and per-channel rules. Add more entries to groups in access.json — no sento command needed, the plugin re-reads the file on every incoming message.