The repo README is the clearest direct primary source for what Proof of SQL claims to be: a high-performance ZK prover for SQL queries over untampered data, positioned as faster and more query-specific than generic zkVM-style approaches for structured analytics.
Current Space and Time technical docs make the reusable mechanism more legible than the parent company homepage alone. They explicitly describe the query lifecycle: SQL AST parsing, witness-column generation, homomorphic commitments, polynomial constraints, multilinear sum-check proving, and verifier-contract checking.
The current docs also make the control-plane split legible: a developer compiles a proof plan, sends it through QueryRouter with payment / callback metadata, and then consumes proven result bytes inside a callback, rather than directly embedding heavy computation into the calling contract.
The technical docs claim that one proof covers both data-integrity and query-correctness guarantees, which is the strongest reason to catalog this as a distinct proving layer rather than leaving it folded into the broader Space and Time chain entry.
No standalone Proof of SQL whitepaper surfaced in this pass; the broader Space and Time whitepaper appears to be the nearest canonical paper, while the repo README and docs remain the best source of current operational detail.