How I Built a Crypto Address Validation API

Ismail Shahzad — Fri, 16 Jan 2026 15:10:03 +0000

Hey Everyone,
I'm a Full Stack Developer currently diving into Web3.

Recently, I was working on a practice Dapp and needed to transfer funds to a smart contract I wrote. I pasted the address, hit send, and... nothing.

I realized later that there was a typo in the contract address. The funds were lost forever(they were just some testnet ETH, but it still stung 🙂)

Then I thought that if this could happen on the testnet, then certainly it can happen on the main network as well.

I looked up for some simple APIs, but everything was either too expensive or too limited to use in an actual product. So, I built my own.

Introducing ChainCheck API

It's a lightweight REST API that simply validates if a crypto address is valid for a certain chain.

Supports 120+ Chains: (ETH, BTC, SOL, etc.)
It's simple to use. Just hit the endpoint with the address and chain symbol.
You can test it immediately using the free tier.

This is my first proper SaaS project and it is still in the early MVP phase. There might be some bugs, so I would love your feedback! You can test the API or reach out via the support email on the page.

Link: https://www.chaincheckapi.com

DEV Community: Ismail Shahzad

How I Built a Crypto Address Validation API