# Why use ChainAPI?
The simple answer is ChainAPI makes deploying an Airnode easier in comparison to building and deploying without, see Build an Airnode. Additionally, ChainAPI gets you to monetization faster and makes Airnode updates effortless. Once built, Airnode connects your API data to an entire universe of decentralized applications through its light, secure, and effortless Web3 API gateway. See Why use Airnode? for more reasons to use an Airnode.
The deployed Airnode can serve API provider data to smart contracts using dAPIs and the request/response protocol contract (Airnode RRP).
- A) Airnode supports on-chain dAPI values via the off-chain data feeds service managed by API3. The data feeds maintains dAPI values by checking the deviation between a dAPI's on-chain value and the API provider's value sourced by Airnode.
- B) Airnode can respond to requests made by smart contracts using the Airnode RRP contract.