Getting Started

Welcome to FIO Protocol Developer's Hub. This page will help you get started with FIO Protocol.

🎓 Learn About the FIO Protocol

This site is offers technical information about the FIO Protocol, including guides on how to integrate it into your application. If you are looking for high-level information about what is FIO Protocol, best head over to the Main FIO Protocol Website where you can find answers to questions such as:

...and much more!

🔍 Look-up FIO Handle

The primary way you can integrate FIO, is to let your users use a FIO Handle (e.g. vitalik@safu) instead of a blockchain public address (e.g. 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045).

Behind the scenes use a simple REST API call to get the associated public address on a specific blockchain for specific token:

➡️Send this

curl --request POST \
     --url \
     --header 'accept: application/json' \
     --header 'content-type: application/json' \
     --data '
  "fio_address": "vitalik@safu",
  "chain_code": "ETH",
  "token_code": "USDT"

⬅️Get this

  "public_address": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"

See Resolve FIO Handle Guide for more information.

📢 But wait, there is more...

If you have already integrated the FIO Handle look-up, we've got more for you. Here's what else you can find on this site.

Benefits of integration

Do you know that by integrating FIO Protocol into your application you can not only enhance the user experience and decrease support costs, but also earn FIO Tokens for every transaction of your users?

Checkout the Benefits of Integration guide for more information.

Advanced Integration Options

FIO Protocol can offers multiple benefits to your users. For example you may choose to enable FIO Requests and let your users to request and transfer any crypto token in an easy, error-free, and secure way.

OptionEnable your users to...
FIO Handle...register and manage FIO Handles and FIO Domains.
FIO Handle FIO Handles to public addresses.
FIO Request...send and receive FIO Requests.
FIO Data...send and receive FIO Data.
FIO Token...send and receive FIO Tokens.
NFT Signatures...sign and manage NFT Signatures.
Wrapped FIO Token...wrap and unwrap FIO Tokens.
Wrapped FIO Domain...wrap and unwrap FIO Domains.
Transaction History...see FIO Chain transaction history for their account.
Transaction Streaming...quickly recognize incoming FIO Token transfers.
Fetch FIO Chain State Data...access any information stored on FIO Chain.
Transaction Provider ID...earn rewards for you.
FIO App...access state-of-the-art FIO Tool without writing the code yourself.
Registration Website...register FIO Handle or Domain without writing the code yourself.
MetaMask using FIO Wallet Snap...access FIO Protocol functionality using MetaMask.
Wallet as a Service...hold blockchain assets using integrated non-custodial and FIO-enabled wallet.

You can build the interface yourself using our APIs and SDKs or link of to the FIO App or Registration Site.

Integration Use Cases

See how FIO Protocol may be integrated in specific crypto applications, such as Centralized Exchanges or Non-custodial Wallet.

Write Transactions

All write transactions to FIO Chain have to be signed by a FIO Private Key and serialized. Checkout the Write Transactions Guide for information on how to do it.


When you are building the FIO Protocol integration you will need to test it. Find out more about FIO Testnet in the Testing Guide.

APIs and SDKs


FIO Chain Getter APIFIO Chain Getter API offers multiple endpoints design to return information about the FIO Chain or specific FIO Handles, FIO Requests, FIO Data, NFT Signatures, or FIO Chain accounts.
FIO Chain V1 History APIFIO Chain V1 History API offers returns historical information about FIO Chain transactions.
FIO Chain Actions APIFIO Chain Action API allows a write transaction to be submitted to the FIO Chain.
FIO Handle Registration APIFIO Handle Registration API offers the ability to register a FIO Handle or FIO Domain either when FIO Foundation has offered free registration to the integrator, or if the integrator would like the FIO Foundation to collect the payment directly from the user.
FIO Service APIFIO Service API is run by the FIO Foundation and returns some FIO Chain statistics, which may be useful for some integrators.



TypeScript SDK is maintained by paid Workers of the FIO Foundation DAO and is the most up-to-date. Check out this SDK Sandbox:


Other SDKs

The following is a list of existing opensource FIO libraries. They made not be actively maintained.

Kotlin SDKInformation and documentation can be found on the Kotlin SDK repo.
Swift SDKInformation and documentation can be found on the Swift iOS SDK repo.
Go SDKThe Go SDK is developed and supported by Blockpane. Information and examples can be found on the Go SDK repo.

FIO Chain

The FIO Protocol runs on FIO Chain, a fully decentralized public Delegated Proof of Stake (DPoS) blockchain that is designed specifically to support the the unique usability requirements of the FIO Protocol.

To better understand how the FIO Chain works checkout this Overview and also FIO Chain Details and Protocol Guides.

If you want to run your own FIO Chain node, checkout FIO Chain Node Guide.

If you want more information about FIO Chain Block Producers or if you are thinking of becoming one, checkout the Block Producers Guide.

Contributing to FIO

Want to get involved? Checkout Contributing to FIO Guide for information about FIO Improvement Proposals, Bug Bounty Program or how to participate in governance of the FIO Protocol.

FIO Brand Assets