Skip to main contentBult.ai offers flexible compute sizes to match your app’s needs, billed per minute. Free tier includes XS, S, and M; Pro plan (September 2025) unlocks L to 3XL. Configure in Canvas UI’s “General” tab in “Edit Service”:
| Size | vCPU | RAM | Price (Monthly) | Tier | Use Case |
|---|
| XS | 0.1 | 256 MB | $2.7 | Basic/Pro | Prototypes |
| S | 0.25 | 512 MB | $5.4 | Basic/Pro | Small Apps |
| M | 0.5 | 1 GB | $12 | Basic/Pro | Web Apps |
| L | 1 | 2 GB | $24 | Pro | APIs |
| XL | 2 | 4 GB | $48 | Pro | Databases |
| 2XL | 4 | 8 GB | $96 | Pro | High-traffic |
| 3XL | 8 | 16 GB | $192 | Pro | Enterprise-scale apps |
- Instances: Free tier supports 1–2 instances per service; Pro allows up to 10.
- Scaling: Auto-scaling available with Pro plan. Manual scaling in Canvas UI.
- Usage: Monitor CPU/RAM in app.bult.ai/usage. Example: XS at 21.12 hours costs $0.03 (CPU) + $0.04 (RAM).
- Limits: Free tier caps at 0.5 vCPU, 1GB RAM total. Pro supports up to 8 vCPU, 16GB RAM.
- Optimization: Start with XS for prototypes. Upgrade to M/L for production to avoid “Out of capacity” errors.
Example: Deploy an Express.js app with XS compute:
- Select “GitHub Repository” in Canvas UI.
- Set compute to XS (0.1 vCPU, 0.25 GB RAM).
- Deploy and monitor costs in app.bult.ai/usage.
