Guarantees

Write Durability

Every write is committed to a WAL (Write-Ahead Log) entry in R2 before acknowledging. R2 provides 11 nines of durability — your data is safe.

Read Consistency

BudgetVec provides eventual consistency for reads after writes. In practice, writes are visible within 1–2 seconds as the Pufferfish cache warms.

Multi-Tenant Isolation

Each tenant's data is completely isolated at the storage layer via R2 key prefixing. There is no shared state between tenants — a bug or overload in one tenant cannot affect another.

Availability

Cloudflare Workers run across 300+ data centers. BudgetVec inherits this availability profile, targeting 99.9% uptime for Scale plans and 99.99% for Enterprise.