Add roadmap

Author: ZIJ

AGENTS.md

@@ -623,14 +623,38 @@ fly secrets list -a catty-api
 
 ---
 
-## Future Milestones
-
-### Milestone 2: Billing & Quotas
-- Add usage tracking per user
-- Implement billing via Stripe
-- Add session time limits and quotas
-
-### Milestone 3: Enhanced Features
+## Roadmap
+
+### Custom Domain
+Move to own domain (e.g., `api.catty.sh`) so no Fly URLs are exposed to users:
+- Register domain
+- Configure Fly custom domains for both `catty-api` and `catty-exec`
+- Update CLI default API URL
+- Update WebSocket connect URLs returned by API
+
+### Usage Metering & Billing
+Track per-user token usage and implement billing:
+- **Token tracking**: Intercept/proxy Anthropic API calls to count tokens per user, or use Anthropic's usage API if available
+- **Database**: Supabase for users, sessions, and usage records
+- **Pricing model**: Free tier (e.g., X tokens/month) + flat subscription (~$25/mo for unlimited or higher cap)
+- **Goal**: Cheaper than running Claude Code locally with your own API key
+- **Billing integration**: Stripe for payment processing (simple checkout, no metered billing complexity initially)
+
+### Multi-Key API Pool
+Handle load spikes by rotating through multiple Anthropic API keys:
+- Store keys in database (Supabase)
+- Round-robin or least-recently-used selection when spawning sessions
+- Key health tracking (rate limits, errors)
+- Admin interface to add/remove keys
+
+### Database Backend (Supabase)
+Replace in-memory session storage with persistent database:
+- **Users table**: id, email, workos_id, created_at, subscription_status
+- **Sessions table**: id, user_id, machine_id, created_at, ended_at, tokens_used
+- **API keys table**: id, key (encrypted), is_active, usage_count, last_used_at
+- **Usage table**: user_id, date, tokens_in, tokens_out
+
+### Future Enhancements
 - Session resume (reconnect to existing session)
 - Download workspace changes back to local
 - Multiple concurrent sessions per user

README.md

@@ -72,6 +72,13 @@ Maximum upload size: 100MB
 
 **Files not appearing**: Check that your workspace is under 100MB and files aren't gitignored.
 
+## Roadmap
+
+- **Custom domain** - Move away from *.fly.dev URLs
+- **Usage metering & billing** - Track per-user token usage, free tier + subscription ($25/mo target)
+- **Multi-key support** - Pool of API keys for handling load spikes
+- **Database backend** - Persistent storage for users, sessions, and usage (Supabase)
+
 ## Development
 
 See [AGENTS.md](AGENTS.md) for architecture details, deployment instructions, and contribution guidelines.