Agent skill · software engineering · starchild-ai-agent
across-bridge
Bridge ETH and ERC-20 tokens across EVM chains via Across Protocol v3. One function for a quote, one function for the entire end-to-end bridge (approval + deposit + arrival verification). Use when the user wants to move tokens between chains (e.g. "bridge 50 USDC from Base to Arbitrum", "send ETH from Ethereum to Optimism", "move USDT Arbitrum → Base"). Supports Ethereum, Arbitrum, Optimism, Base, Polygon, BSC, Linea, zkSync, Scroll, Mantle. Fast settlement (seconds to minutes).
Why this skill is useful
Adds executable Python functions for bridging tokens across EVM chains, which are not commonly found in public documentation.
What it needs
Requires pip, python3 installed locally. About 3k tokens when loaded. Last updated 2026-08-06. 22 stars on the source repository.
What this skill does
🌉 Across Bridge Bridge tokens between EVM chains using Across Protocol v3. Across is an intent-based bridge: relayers front the liquidity on the destination chain and get repaid on the origin chain, so settlement is fast (seconds to a few minutes) and fees are low (0.05–0.5%). When to Use Cross-chain token transfer: "bridge 50 USDC from Base to Arbitrum" L1 ↔ L2 movement: "send 0.01 ETH from Ethereum to Optimism" Stablecoin hops: "move USDT from Arbitrum to Base" Speed matters: Across fills in seconds–minutes vs native bridges (7 days) Supported Chains Ethereum · Arbitrum · Optimism · Base · Polygon · BSC · Linea · zkSync · Scroll · Mantle Supported Tokens ETH · WETH · USDC · USDT · WBTC · DAI How to Call All operations are Python functions exposed under core.skilltools. Because the skill name contains a hyphen, use the modules dict to access it: bridgequote(fromchain, tochain, token, amount, wallet=None) Get a live quote — no on-chain action. Returns output amount, fees, estimated fill time, and (if wallet is provided) ready-to-sign approval + bridge transactions. bridgeexecute(fromchain, tochain, token, amount, wallet, confirmarrival=True) One call does everything: 1. Fetches a fresh quote from Across /swap 2. Sends ERC-20 approval to the SpokePool (if needed; skipped for native ETH) 3. Sends the depositV3 bridge transaction 4. Polls the destination-chain balance until funds arrive (or timeout) Returns a full receipt with status, outputamount, approvaltx, bridgetx, and arrivalconfirmed. bridgestatus(originchain, deposittxhash) Check the fill status of a submitted deposit via Across's status API. Workflows Just get a quote (no execution) Key fields in the response: outputamounthuman — tokens the recipient will receive fees.totalpct — fee percentage (e.g. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills starchild-ai-agent/across-bridge