/evm-atlas

Gas.zip Bridging

Overview

Use Gas.zip as a read-only source for native-gas bridge quotes, per-chain limits and liquidity, deposit status, and destination fills after the known origin and destination chains are confirmed against references/generated/target-mainnets.json.

Default to the API base URL, which needs no key:

https://backend.gas.zip

Never execute bridge steps from this skill. Returned calldata and contractDepositTxn objects are for inspection only; route any deposit preparation, simulation, and broadcast to cli-cast.

Gas.zip is a solver-fill native-gas bridge: the user deposits native currency on the origin chain, and a Gas.zip signer sends a plain native transfer (empty calldata) to the recipient on each destination chain. It identifies destinations by its own short IDs, not chain IDs; resolve them through GET /v2/chains and never hardcode a table.

Contract deposits call deposit(uint256,bytes32) (selector 0xc9630cb0). The uint256 packs destination short IDs; the bytes32 is the recipient address left-aligned (right-padded with zeros), not ABI address padding. Verified 2026-10-01: GasZipV2 at 0x5D5a72859b8EBAFcf459164F64400012F5A3C5E0 on Arbitrum Nova (Blockscout-verified source). Verify the contract on each other origin chain before treating a deposit as Gas.zip.

Read-Only Router

1. Known origin deposit tx hash: call GET /v2/deposit/{hash}. deposit carries origin chain, block, sender, recipient, shorts, value, and status; txs[] lists destination fills with chain, hash, signer, value, and status. An empty {} is indexing lag, not absence: observed for about six minutes after the origin receipt on 2026-10-01. Recheck later and verify the fill on the destination chain through provider routing. A txs[] entry with refund: true, chain equal to the origin, and an errtime is a refund to the sender on the origin chain, not a destination fill; it can stay SEEN until Gas.zip has origin-chain liquidity. Verify it by the sender's origin balance, not the signer nonce. errtime advances on each failed retry, so a recent value means Gas.zip is still retrying. Users have no on-chain recovery path: deposits stay in the deposit contract, which only its owner can withdraw, while fills and refunds are paid from the separate signer balance. Observed 2026-10-02: the Nova contract held about 1 ETH while the Nova signer bal was below the pending refund. For stuck refunds, compare the contract balance with the origin bal and point the user to Gas.zip support (Discord or Telegram, linked from https://www.gas.zip/) with the deposit hash.
2. Known sender/recipient address: call GET /v2/user/{address}. An empty user array has the same lag caveat.
3. Quote: call GET /v2/quotes/{originChainId}/{amountWei}/{destinationChainIds}?from=<address>&to=<address>. quotes[].expected is destination wei; expires is a Unix timestamp. The output is an estimate, not a fill guarantee.
4. Supported chains, limits, and liquidity: call GET /v2/chains. Per chain: chain (chain ID), short, inbound, minInbound/maxInbound and minOutbound/maxOutbound (USD), the *Native wei equivalents, and bal (destination liquidity in wei). Check the destination's maxOutbound and bal before relying on a quote. A quote above maxOutbound fails with Chain Limit Exceeded, so larger amounts need sequential deposits; re-quote and recheck bal before each, because fills drain it. Observed 2026-10-01: a deposit accepted while destination liquidity was short stayed SEEN with a null fill hash, and later quotes returned Insufficent Liquidity.

Example status lookup:

curl -sS "https://backend.gas.zip/v2/deposit/0xTX_HASH"

Coverage Notes

Verified 2026-10-01: for Arbitrum Nova to Arbitrum One native ETH, Relay and Across listed no Nova route, Layerswap reported the asset unsupported, and LI.FI's only route was Gas.zip with an added LI.FI fee. Recheck live coverage before reusing this conclusion.

Sources

• https://dev.gas.zip/
• https://arbitrum-nova.blockscout.com/address/0x5D5a72859b8EBAFcf459164F64400012F5A3C5E0