ADR-0010: Slack as Hermes Messaging Gateway
Slack is the current messaging gateway for the Hermes Agent. The gateway history:
- Telegram was the original plan — rejected because Telegram requires a €1.39 SMS verification fee for new accounts in France (violates free-tier budget + sovereignty).
- Discord was chosen as the day-one gateway (free, email-only signup, clean bot API, good markdown). This was the gateway from initial deployment until May 2026.
- Slack replaced Discord in May 2026 when Discord API keys were retired. Slack offers equivalent functionality: free tier, email signup, mobile + desktop apps, native Hermes support, and good markdown rendering.
Signal was previously considered but rejected for bot setup complexity (requires signal-cli + Java). WhatsApp was rejected due to Meta ownership (sovereignty concern).
Considered Options (at time of original decision)
Section titled “Considered Options (at time of original decision)”| Option | Cost | Signup | Markdown | Bot setup | Sovereignty |
|---|---|---|---|---|---|
| Discord ✅ (original) | Free | Email only | ✅ Good | Simple | US company |
| Slack ✅ (current) | Free tier | ✅ Good | Simple | US company | |
| Telegram | €1.39 (FR, new accounts) | Phone + fee | 🟡 Partial | Simple | EU-founded |
| Signal | Free | Phone (OK) | ❌ None | Complex (signal-cli) | Best |
| Free | Phone (OK) | ❌ None | Simple | Meta-owned ❌ |
Consequences
Section titled “Consequences”- All docs previously referencing “Discord” or “Telegram” for Hermes gateway now use “Slack”
hermes-gatewaysystemd service config uses Slack token- Health Dashboard alerts (Uptime Kuma) route via Slack
- Djuly access: Slack account (email signup, no barrier)
- Discord is fully deprecated — API keys removed, gateway disabled