> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.0x.org/cross-chain/cross-chain-api/key-concepts/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.0x.org/_mcp/server.

# Key Concepts

> Developer documentation for the 0x API. Embed swaps in your onchain app. Access 10+ million tokens with liquidity from 150+ exchanges with a single API.

## Docs

- [Tracking Transaction Status](https://docs.0x.org/cross-chain/cross-chain-api/key-concepts/tracking-transaction-status.md): Understand the status lifecycle of a cross-chain transaction returned by /status.
- [Handling Failures and Recovery](https://docs.0x.org/cross-chain/cross-chain-api/key-concepts/handling-failures-and-recovery.md): What happens when a bridge fails, how recovery works, and what your integration should do for each scenario.
- [Native Tokens Handling](https://docs.0x.org/cross-chain/cross-chain-api/key-concepts/native-tokens-handling.md): How native tokens (ETH, SOL, TRX) work in cross-chain swaps.
- [Understanding Bridging Costs](https://docs.0x.org/cross-chain/cross-chain-api/key-concepts/understanding-bridging-costs.md): All the costs related to executing a cross-chain swap, and where each appears in the quote response.