@zktable/contracts

Soroban (Rust) on-chain layer for zkTable: the generic game referee contract plus the UltraHonk proof verifier it depends on.

Layout

crates/
  ultrahonk-verifier/   # pure-Rust UltraHonk verifier (BN254 host functions)
  test-utils/           # test helpers for the verifier
contracts/
  verifier/             # thin verifier wrapper contract (M0 anchor) — zktable-verifier
  referee/              # generic game referee (M2+)  [added in M2]
scripts/
  deploy_verifier.sh    # build + deploy + verify a circuit's proof on testnet

Provenance

crates/ultrahonk-verifier and contracts/verifier are vendored from yugocabrio/rs-soroban-ultrahonk (MIT). See crates/ultrahonk-verifier/VERIFIER_PROVENANCE.md. The verifier implements UltraHonk verification in Rust using Stellar's BN254 host functions (Protocol 26+). We treat it as an audited, load-bearing dependency and build the zkTable referee on top of it unchanged.

Toolchain (pinned — see repo rust-toolchain.toml)

• Rust stable (1.94+), target wasm32v1-none (soroban-sdk 26 rejects wasm32-unknown-unknown).
• soroban-sdk 26.0.1, stellar CLI 23+.
• Build with cargo +stable build --release --target wasm32v1-none. The stellar contract build wrapper may select the wrong toolchain — prefer the explicit cargo command above (already wired into pnpm build).

Verifier contract API (zktable-verifier)

__constructor(vk_bytes: Bytes)                       // VK immutable at deploy
verify_proof(public_inputs: Bytes, proof_bytes: Bytes) -> Result<(), Error>
vk_bytes() -> Bytes

PROOF_BYTES = 14592. Contract error #4 = VerificationFailed.

Reproduce M0 (proof verified on live testnet)

# 1. build the circuit artifacts (proof / vk / public_inputs)
packages/circuits/scripts/build_one.sh simple_circuit
# 2. build + deploy the verifier and verify the proof on-chain
packages/contracts/scripts/deploy_verifier.sh simple_circuit alice testnet

A valid proof returns null (Ok); a tampered proof fails with contract error #4.

Test

cargo +stable test        # native unit + Soroban-host integration tests (needs built circuit artifacts)