Design
How prices are computed
Where Brunel's prices come from, the formula for every component, the usage assumptions you can edit, currencies, environments, and what happens when a service has no official price.
Sources
| Provider | Region | Catalog currency | Source |
|---|---|---|---|
| AWS | Paris (eu-west-3) | USD, converted to EUR | AWS Price List API |
| Scaleway | Paris (fr-par) | EUR | Scaleway's public price catalog |
Catalogs are versioned by month, carry the exchange rate used, and link the official pages each price comes from. The catalog date is shown next to every price.
The formula
For each component:
monthly = hourly price × 730 h × replicas × (high availability ? HA multiplier : 1)
+ storage GB × price per GB-month
+ backup GB × backup price per GB-month
+ usage lines (requests, egress, logs, metrics…) from the assumptionsA tier's total is the sum of its components, plus its non-production environments: staging costs 0.35 × production and development 0.10 × production by default. Every term is a line in the cost breakdown.
Assumptions
Usage-based services need assumptions: requests, egress, logs, metrics. Brunel derives them from your context (peak requests per second, monthly active users, data volume) and shows every one of them. You can edit them in the costs view and the tier re-prices instantly in your browser; the saved version keeps the defaults.
| Assumption | Default |
|---|---|
| Hours per month | 730 |
| Traffic served by the CDN | 60 % |
| Log retention | 30 days |
| Custom metrics per component | 10 |
| Alarms per component | 2 |
| Trace sampling | 5 % |
| Uptime checks | every 5 minutes |
| WAF rules | 5 |
| CI builds per month × minutes per build | 60 × 8 |
| Container registry | 5 GB |
| Backup size vs. data | 50 % |
| Scheduled job duty cycle | 5 % |
| Function duration | 200 ms |
| Staging vs. production | 0.35 × |
| Development vs. production | 0.10 × |
Currencies
Designs are stored in euros. Switching to US dollars converts with the catalog's own rate, instantly and without the AI.
Components without an official price
When a service has no official price in the catalog (a third-party fallback, for example), the component says "no official price" instead of guessing, and the validator reports it as PRC-000 (info). Its cost is not included in the total.
Price watch
When providers publish new prices, a new catalog month is added and the price watch recomputes your designs. See Price watch.