> For the complete documentation index, see [llms.txt](https://docs.xy.finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.xy.finance/single-bridge-integration.md).

# Single Bridge Integration

- [yBridge API](https://docs.xy.finance/single-bridge-integration/ybridge-api.md)
- [Get Quote](https://docs.xy.finance/single-bridge-integration/ybridge-api/get-quote.md): Returns feasible routes and best quotations
- [Get Allowance](https://docs.xy.finance/single-bridge-integration/ybridge-api/get-allowance.md): Returns the token spend allowed by an address on behalf of the crypto holder.
- [Build Approval Transaction](https://docs.xy.finance/single-bridge-integration/ybridge-api/build-approval-transaction.md): Returns the transaction data for the approval of token spend
- [Build Swap Transaction](https://docs.xy.finance/single-bridge-integration/ybridge-api/build-swap-transaction.md): Returns the swap data for bridging tokens
- [Get Cross-Chain Status](https://docs.xy.finance/single-bridge-integration/ybridge-api/get-cross-chain-status.md): Returns the status of cross-chain transactions
- [Get Pool Liquidity](https://docs.xy.finance/single-bridge-integration/ybridge-api/get-pool-liquidity.md)
- [Get Fee Structure](https://docs.xy.finance/single-bridge-integration/ybridge-api/get-fee-structure.md)
- [Recommended Tokens](https://docs.xy.finance/single-bridge-integration/ybridge-api/recommended-tokens.md): Allows any third party that capitalizes on our open APIs to access a list of tokens that we support via our endpoint
- [Supported Blockchains](https://docs.xy.finance/single-bridge-integration/ybridge-api/supported-blockchains.md): Lists a good selection of  blockchains that are currently supported by yBridge
- [Error Message](https://docs.xy.finance/single-bridge-integration/ybridge-api/error-message.md)
- [Change Log](https://docs.xy.finance/single-bridge-integration/ybridge-api/change-log.md): Keeps you updated with the most recent slight changes to our API at regular intervals
- [yBridge Contract Integration](https://docs.xy.finance/single-bridge-integration/ybridge-contract-integration.md)
- [Integrate YBridge Contract](https://docs.xy.finance/single-bridge-integration/ybridge-contract-integration/integrate-ybridge-contract.md): XY Finance deploys smart contracts on most mainstream chains and benefits all types of users in terms of secure cross-chain swaps.
- [Bridge Example](https://docs.xy.finance/single-bridge-integration/ybridge-contract-integration/integrate-ybridge-contract/bridge-example.md): This is a simple bridge request (without invoking swap on the source chain) example
- [Latest Upgrade ( 2024/07/17 )](https://docs.xy.finance/single-bridge-integration/ybridge-contract-integration/integrate-ybridge-contract/latest-upgrade-2024-07-17.md): There will be additional charge imposed by some DEX aggregators which provide swapping service. Therefore, the YBridgeV3 contract is upgraded to reflect such expense.
- [Migrate from V2 to V3](https://docs.xy.finance/single-bridge-integration/ybridge-contract-integration/integrate-ybridge-contract/migrate-from-v2-to-v3.md): This document provides a detailed outline of the key changes between XSwapper (V2) and YBridge (V3) and guides you through the necessary steps to migrate your system
- [Integrate YBridgeVault Contract](https://docs.xy.finance/single-bridge-integration/ybridge-contract-integration/integrate-ybridgevault-contract.md)
- [Maximum Available Liquidity](https://docs.xy.finance/single-bridge-integration/ybridge-contract-integration/integrate-ybridgevault-contract/maximum-available-liquidity.md)
- [Migrate from V2 to V3](https://docs.xy.finance/single-bridge-integration/ybridge-contract-integration/integrate-ybridgevault-contract/migrate-from-v2-to-v3.md): This migration guide is intended for developers working with our smart contract. This document outlines the key changes between the current and upcoming versions, including function parameter renames,
- [(Legacy) Integrate X Swap Contract](https://docs.xy.finance/single-bridge-integration/ybridge-contract-integration/smart-contract.md): XY Finance deploys smart contracts of Swapper (X Swap) on most mainstream chains and benefits all types of users in terms of secure cross-chain swaps.
- [(Legacy) Bridge Example](https://docs.xy.finance/single-bridge-integration/ybridge-contract-integration/smart-contract/legacy-bridge-example.md): This is a simple bridge request (without invoking swap) example
- [(Legacy) Integrate Y Pool Contract](https://docs.xy.finance/single-bridge-integration/ybridge-contract-integration/legacy-integrate-y-pool-contract.md)
- [(Legacy) Maximum Available Liquidity](https://docs.xy.finance/single-bridge-integration/ybridge-contract-integration/legacy-integrate-y-pool-contract/legacy-maximum-available-liquidity.md)
- [xAsset Bridge](https://docs.xy.finance/single-bridge-integration/xasset-bridge.md): Upgrade you token into multi-chain world
- [How to Develop Under XY Standards](https://docs.xy.finance/single-bridge-integration/xasset-bridge/how-to-develop-under-xy-standards.md)
- [Function Interface for Token Contract](https://docs.xy.finance/single-bridge-integration/xasset-bridge/how-to-develop-under-xy-standards/function-interface-for-token-contract.md)
- [How to Deposit / Withdraw Liquidity](https://docs.xy.finance/single-bridge-integration/xasset-bridge/how-to-deposit-withdraw-liquidity.md): How to add / remove liquidity using pool-based method
- [Direct Contract Interaction](https://docs.xy.finance/single-bridge-integration/xasset-bridge/how-to-deposit-withdraw-liquidity/direct-contract-interaction.md)
- [Through the Explorer](https://docs.xy.finance/single-bridge-integration/xasset-bridge/how-to-deposit-withdraw-liquidity/through-the-explorer.md)
- [Set up Your Own Validator](https://docs.xy.finance/single-bridge-integration/xasset-bridge/set-up-your-own-validator.md): Explain how transaction verify by multiple validator