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Architecture

Kurabase combines a relational execution layer with canonical EVM state.

REST request
  -> relational execution
     -> read: current projection snapshot
     -> write: deterministic WritePlan
        -> verified identity + RLS checks
        -> gateway-attested account transaction
        -> Privy / ZeroDev user operation
        -> canonical chain state

Reads​

The gateway may maintain a relational projection for joins, CTEs, views, aggregates, and window functions. The projection is rebuildable. A normal read must not intentionally return an older projection when the current chain head is known.

Writes​

For a production application write, the gateway constructs a deterministic WritePlan, validates the caller's identity and applicable relational policy, and signs a five-minute GatewayPlan attestation. The attestation binds the gateway delegation epoch, the exact account, identity context, current revision, every encoded operation, a nonce, and expiry. It also binds the digest of the exact authenticated session. This makes an individual session revocation invalidate a pending plan before execution.

The gateway returns calldata for executeGatewayPlan; it does not submit that calldata. Privy sends it from the user's connected external wallet or embedded wallet, normally through a ZeroDev smart account. The contract requires msg.sender to equal the account named in the attestation, so the gateway EOA cannot replay its own signature as a user write. A user-approved, scoped ZeroDev session key may send the same call only through that account.

KURA_AA_ENABLED defaults to true for a gateway deployment. A new local kura start instance begins with direct commits so SQL-first development works without an account provider. Configure a public Privy App ID in Dashboard Authentication to switch that local instance to account-owned plans immediately. The local operator stores only public provider IDs; Privy verification secrets, sponsor credentials and session keys remain outside the gateway/Dashboard boundary. See Privy and account abstraction for the execution and credential boundary.

SQL semantics​

ISO SQL:2023 is a semantic reference, with necessary PostgreSQL and Supabase-style extensions. It is not a claim of complete standards conformance.

Representative expected coverage includes relational queries, mutations, constraints, RLS, returning and upsert, selected views, and SQL-language RPC. Unsupported behavior returns an explicit error. There is no PostgreSQL wire protocol.