Current status

The multisig-DA PoC implementation is complete enough to run the full native bridge round trip locally with real OCaml-produced commits. It has not yet been promoted to a persistent live Sepolia deployment.

Working today

• The OCaml committer exports the real wrap proof and verifier index, full Pickles statement skeleton, zkApp statement, account-update body preimage, actions, source outer state, and archived native-withdrawal preimages.
• SP1 performs accumulator checking, deferred-value reconstruction, wrap public-input reconstruction, and outer Kimchi verification through the o1 Pickles verifier path.
• Settlement receipts bind all eight outer-state fields, outer action state and length, synchronized outer checkpoint, slot range, Ethereum domain, batch number, and verification-key identifier.
• The V2 settlement receipt binds exact inner actions to a depth-16 Keccak tree.
• Finalized native ETH deposit logs are converted into exact five-field outer Witness actions by the bridge guest.
• Solidity verifies state continuity, records synchronized checkpoints, enforces withdrawal delay, and releases native ETH with an ordinary Merkle proof.
• The gateway implements the sequencer's Mina GraphQL subset, persists proof jobs, gates paid requests on approval, waits for consensus finality, and rolls its virtual Mina view back on Ethereum reorgs.
• A fresh gateway database rebuilds deposits, accepted bridge transitions, settlements, claims, the virtual outer account/action sequence, and settled withdrawal leaves from finalized Ethereum calldata/events plus canonical archive preimages; it does not require the original local proof jobs.
• Public browser APIs expose deployment config, resumable deposit state, and precision-safe withdrawal proofs. Finalized deposits can be queued automatically without an operator API call.
• @zeko-labs/eth-bridge-sdk owns Ethereum wallet operations and composes the existing bridge SDK for sequencer-side deposit finalization and withdrawal requests. The Actions services consume the gateway's Mina archive shape.
• bridge-ui/ is a standalone React application for the four browser-owned operations: ETH deposit, Zeko deposit finalization, Zeko withdrawal request, and Ethereum claim. It uses injected Ethereum wallets and Auro, with the PoC signing domain fixed to Mina testnet.
• explorer-ui/ is a standalone React explorer for L2 blocks, transactions, accounts, SP1/Ethereum settlements, deposits, withdrawals, and canonical claims. The gateway joins a read-only OCaml archive view with its existing Ethereum and bridge indexes.
• Pending native withdrawal requests are classified in L2 transaction lists and detail pages before their next settlement, and browser activity survives reloads without relying on wallet/UI memory as protocol state.
• The machine-local delivery workflow generates separated retained identities, builds digest-pinned gateway/Zeko/DA images, deploys only behind an explicit Sepolia deployment confirmation, materializes runtime files, and preflights the complete contract role/vkey/source identity.

Verified local checkpoint

The July 15, 2026 retained-identity round trip used a genuine two-commit OCaml export with DA quorum 2 of 3 and Mina signing domain testnet. Its verifier index SHA-256 is a9bca935bad09638d2e335a7cfc4ecc110389d15c033db6b0413593ca9193c74. It locked 10 ETH and claimed 5 ETH after the deposit-synchronizing and withdrawal-bearing settlements. The browser-readiness path submitted the deposit and claim through @zeko-labs/eth-bridge-sdk, automatically queued the finalized deposit, and observed its outer Witness through the production Actions indexer/API pair.

The live-sequencer checkpoint additionally runs that browser SDK against the real OCaml bridge GraphQL mutations. Deposit finalization is prepared from the Actions API, signed by the browser client, accepted and proved by the OCaml sequencer, and followed by an Ethereum-routed native withdrawal request. The resulting deposit-synchronizing and withdrawal-bearing commits are exported for settlement validation; this checkpoint generates no SP1 proof.

Execution	SP1 cycles	Ethereum gas in local mock submission
Native deposit bridge	3,435,291	218,336
Deposit-synchronizing settlement	52,191,513,620	275,825
Withdrawal-bearing settlement	52,187,890,758	318,602

This table is the retained full-zkVM audit checkpoint: all guests executed and their public values were checked before submission. The operational gateway now verifies settlement Pickles proofs natively with the same pinned verifier and receipt derivation, so new settlement jobs normally store a null cycle count. API_EXECUTE_ONLY=true still reproduces the full audit. The local verifier accepted empty proof bytes only on Anvil chain ID 31337. No SP1 proof or network request was generated.

ERC-20 branch checkpoint

The ERC-20 port now has the proof and custody seam needed to turn a canonical submitDeposit call into a Zeko witness action:

• Solidity registers an immutable Ethereum-token/Mina-token asset identity and deposit-capacity ceiling, takes exact ERC-20 custody, emits the canonical deposit fields, and protects the locked liability from emergency withdrawal.
• The gateway indexes finalized BridgeDeposit and immutable ERC-20 identity events. Legacy one-token deposits remain encoding V1 with the ZEKO_ERC20_DEPOSIT_LEAF_V2/Ethereum ERC20 deposit V1 wire. Universal registry deposits use encoding V2 and bind the registry index plus canonical Mina record commitment in the ZEKO_ERC20_DEPOSIT_LEAF_V3 Keccak leaf and Ethereum ERC20 deposit V2 Poseidon preimage.
• Zeko's hybrid Ethereum/custom-token circuit authenticates that record, registry index, and both 128-bit asset-ID limbs before an accepted deposit can move a bounded, pre-minted Mina Fungible Token inventory from the bridge vault to the user.
• Withdrawal settlement retains the V3 leaf for legacy encoding V1 and uses a V4 leaf for registry encoding V2, binding the registry index and record commitment alongside the exact inner action, asset ID, ERC-20 token, recipient, and UInt64 amount. Solidity releases only the matching token after the settlement delay, with per-token replay cursors and liabilities.
• The gateway and @zeko-labs/eth-bridge-sdk expose ERC-20 deposit status and delayed token-withdrawal claims. Solidity/Rust share the exact accumulator leaf schema, SP1/OCaml share the exact Poseidon action vector, and the mock-verifier contract test exercises the complete custody, checkpoint, and delayed-release sequence without requesting an SP1 proof.

The universal registry runtime path is also implemented:

• The sequencer accepts one registry account, schema version, approved MFT standard VK ID, shared vault public key, and universal bridge VK ID. Asset records and depth-8 membership witnesses are dynamic circuit inputs. The current schema supports 256 records with at most nine decimals; adding a token does not compile another circuit or VK.
• Registration is an append-only Poseidon Merkle-list transition. Its recursive scan proves dense ordered traversal of every existing leaf and rejects duplicate Ethereum tokens, asset IDs, or L2 owner/token identities.
• Each outer Pickles commit binds the registry public key, root, count, and schema through a domain-separated Poseidon digest in the signed sequencer child's call data. This keeps the checkpoint in the verified call forest without requiring a shadow registry account on Mina L1.
• Solidity proposals remain Pending until a V4 settlement binds the exact ordered (record hash, Mina record commitment) batch and the new L2 registry root/count. Depth-8 Keccak batch proofs activate the corresponding immutable records without requiring Solidity to evaluate Poseidon.
• Registry selectors execute in a dedicated immutable module against namespaced proxy storage. The bridge retains custody configuration behind self-only callbacks; deterministic deployment records the module address and keeps both implementations below Ethereum's EIP-170 bytecode limit.
• The browser SDK validates the returned vault forest and exact full token-owner account-update body, then composes and proves the transaction with the unmodified mina-fungible-token owner's approveBase method.
• The Actions indexer reconstructs immutable records and current membership paths. The SDK resolves by Ethereum token, asset ID, or stable registry index and rejects malformed records, roots, paths, and runtime identities before proving.
• The two-token local gate deploys two unmodified standard owners with distinct derived token IDs, one shared vault key, and one universal bridge VK. It registers and activates both records, finalizes both deposits, submits both withdrawals, and claims the corresponding Ethereum tokens without generating an SP1 proof.

Needed for the live PoC

1. Build and record immutable machine-local images from the final committed source and retained verifier index.
2. Provide a funded Sepolia RPC/admin/gateway identity and a funded Succinct requester, deploy the registry module plus settlement and bridge proxies, and pass preflight.
3. Obtain a network-simulation PGU value for each genuine job, review the capped quote, and explicitly approve the three paid proofs used by the demo.
4. Complete one browser-driven Sepolia round trip and archive transaction, proof-request, cost, confirmation, DA, and balance/liability evidence.

No Sepolia deployment or paid Succinct proof has been performed by the checked in delivery workflow yet. Those remain credential-, funding-, and approval-gated external operations.

Explicitly out of scope

• EIP-4844 blob DA, blob archival, and blob-to-Zeko data-root equivalence.
• Deposit cancellation and refunds.
• Dynamic multi-asset circuit routing within one sequencer and production inventory/governance automation.
• Bridge proof fees.
• A canonical Mina verification-key hash; the PoC uses SHA-256 of the exact verifier-index JSON bytes.
• Production governance, timelocks, and permissionless proof submission.

The old arbitrary-timeout/ERC20 deposit path and separate withdrawal guest are retained for compatibility tests but are disabled by default. They are not the canonical bridge paths described in these docs.