Wallet integration options

Table of contents

  1. Sending crypto using FIO Addresses
  2. FIO Private/Public Key
  3. FIO Address registration outside of wallet
  4. Assigning public addresses to FIO Address
  5. FIO Request and FIO Data
  6. FIO token
  7. FIO Address and FIO Domain registration inside wallet

It is up to the integrating wallet to decide which features of the FIO Protocol they want to implement and how. The following document defines available features and options.

1. Sending crypto using FIO Addresses

The most basic level of integration with FIO Protocol is to enable sending of crypto currency using human-readable FIO Address instead of long cryptic native blockchain public addresses (NBPAs).

This level typically requires updates to the Send crypto currency screen to allow for a FIO Address to be entered in addition to NBPA. FIO Address can be easily identified by looking for a @ (at sign) in the string.

Once FIO Address is entered, it can be resolved to NBPA on a specific blockchain using /get_pub_address API method.

Once NBPA is obtained, the Send transaction executes as if the user entered or scanned the NBPA.

Sample UX

See Sending Bitcoin using FIO Address

2. FIO Private/Public Key

All further integration options will require a FIO Private/Public key pair to be generated and stored inside the wallet.

See Private/Public Keys for more information including testing examples.

3. FIO Address registration outside of wallet

Most FIO Protocol functionality requires a user to have a FIO Address. A FIO Address is an NFT owned by owner FIO Public Key and consists of a username and a domain delimited by an @


The easiest way to facilitate a FIO Address registration is to redirect the users to a Foundation for Interwallet Operability website which enables registration and payment with common crypto currencies, such as Bitcoin. FIO Public Key needs to be passed to the website, so that the FIO Address can be properly assigned to the owner. To learn more see FIO registration site


FIO Address has annual fee associated with them. Fees in the FIO Chain are set by block producers.

Every FIO Address comes with a set number of bundled transactions annually. The specific number is set by the block producers and is currently 100 annually. This bundle is expected to cover most transactions executed by user except token transfer fees and certain governance or domain management fees.

In order to ensure a particular action is covered by the bundle, the wallet should execute /get_fee API method before submitting any signed transaction.

Fetching user’s FIO Addresses

FIO Addresses currently owned by the user (even if registered outside of the wallet) may be fetched using /get_fio_names API method.

Technology Provider ID

Please review the Technology Provider ID section for information on how to earn a portion of the fees paid by your users and how to have your users’ tokens proxied by default.

4. Assigning public addresses to FIO Address

In order allow others to send crypto currency using the user’s FIO Address, it has to be mapped to native blockchain public addresses (NBPAs). This has to be done from within the wallet using /add_pub_address API method as it needs to be signed with user’s private key. For now, this mapping is stored unencrypted, but a privacy mode is being worked on.

It is up to the wallet to decide if this happens automatically, behind the scenes or driven by the user via UI. If the wallet supports multiple NBPAs for the same blockchain at the same time, e.g. multiple bitcoin wallets, the decision will likely need to be made by the user via UI.

Please read Mapping Public Addresses to better understand how public address mappings work.

Sample UX

See Connecting FIO Address to public keys

5. FIO Request and FIO Data

One of the key features of FIO Protocol is the ability to request crypto using FIO Request. The user requesting funds (Payee) can send a FIO Request to a user who is asked to pay (Payer), by only using the Payer’s FIO Address.

FIO Request data, such as amount, currency, and memo field are encrypted and only readable by Payee and Payer.

Please read Encrypting FIO Data to better understand how encryption works.

Submitting new FIO Request

To request funds, Payee’s wallet should submit a new FIO Request using /new_funds_request API method.

Fetching pending FIO Requests

The Payer’s wallet can fetch all new and pending FIO Requests using /get_pending_fio_requests API method.

Rejecting a FIO Request

The Payer’s wallet can reject a FIO Request, which will remove it from the pending list, using /reject_funds_request API Method.

Fetching sent FIO Requests

The Payee’s wallet can fetch all sent FIO Requests and its current status using /get_sent_fio_requests API method.

Recording FIO Data

Anytime crypto is sent using FIO Address, optional metadata such as amount, currency, and memo, may be recorded on the FIO Chain. FIO Data is encrypted and only readable by Payee and Payer.

FIO Data, can be recorded using /record_obt_data API method.

Although /record_obt_data has to be sent any time user is sending crypto currency in response to a FIO Request, it is optional when user sends crypto using FIO Address.

It is strongly encouraged that /record_obt_data is sent at least when the user populates the memo field, as it allows for transaction Memo to be reliably send across different wallets.

When sending FIO tokens using FIO Address you must submit record_obt_data following transfer_tokens_pub_key to ensure FIO Addresses are attached to the transaction. Some wallets and exchanges may be relying on this information to properly account the FIO tokens, e.g. exchange deposit.

Retrieving FIO Data

OBT data can be retrieved using /get_obt_data

This call will return all metadata relevant to the provided FIO Public key, including:

  • Outbound data. Payer’s FIO Address is owned by provided FIO Public key
  • Inbound data. Payee’s FIO Address is owned by provided FIO Public key

Sample UX

See Requesting Bitcoin using FIO Address and Displaying incoming FIO Requests

Example flow

Alice requests 1 BTC from Bob and adds a “Invoice 123” memo

Bob checks his wallet for new requests

  • /get_sent_fio_requests will not return anything as this request was sent by Alice not by Bob.
  • /get_pending_fio_requests will return the request just sent with the status requested and all encrypted data including “Invoice 123” memo. We recommend wallets show this request for Bob to act on.

Bob accepts the request and pays Alice

Step 1
  • BTC public address, amount and memo are decrypted
  • Wallet creates a payment for 1 BTC to provided BTC public address and “Invoice 123” memo.
  • User has the option to modify amount or memo.
  • Once user approves, the transaction is broadcasted to Bitcoin blockchain.
Step 2

Alice checks payment

  • /get_sent_fio_requests will return the request with the status sent_to_blockchain. We recommend wallets show this request as “received”.
  • /get_obt_data will return important encrypted metadata wallets should attach to the request and/or the actual Bitcoin transaction including actual amount, actual memo, transaction ID (obt_id) from Bitcoin blockchain and other data. obt_id may be used to match the information with the actual Bitcoin blockchain transaction.

In Bob’s wallet

6. FIO token

FIO token

FIO Chain’s native token is FIO. FIO is the only token present on the FIO Chain.

There are 1,000,000,000 Smallest Units of FIO (SUFs) inside 1 FIO. All transactions in FIO Protocol are expressed in SUFs.

Transferring FIO token

Tokens on the FIO Chain are transferred using /transfer_tokens_pub_key method.

The method requires payee FIO Public Key. The key is hashed down to an account name and funds are transferred to that account. If that account does not exist, it gets created automatically.

The native EOSIO transfer action is not supported.

Transaction memo

/transfer_tokens_pub_key does not accept a memo field. To attach a memo to a FIO token transfer, a /record_obt_data transaction should be sent after the tokens are transferred and include the token transfer transaction id. /record_obt_data requires that both payer and payee have a FIO Address. If either party does not have a FIO Address transfer of memo is not supported.

Checking token balance

Token balance can be obtained by passing FIO Public Key to /get_fio_balance API method.

Transaction history

See History node

7. FIO Address and FIO Domain registration inside wallet

For wallets desiring full control over the registration user experience, a full suite of FIO Address and FIO Domain registration and renewal API methods are available.

Registering/renewing FIO Domain

FIO Domain can be registered using /register_fio_domain API method and renewed using /renew_fio_domain API method.

Registering/renewing FIO Address

FIO Domain can be registered using /register_fio_address API method renewed using /renew_fio_address API method.

Fetching user’s FIO Addresses and Domains

FIO Addresses and Domains currently owned by the user may be fetched using /get_fio_names API method.

Checking FIO Address or Domain availability

To enable the registering wallet to easily check if a FIO Address or Domain is available for registration, /avail_check API method may be called.

Paying for FIO Addresses on behalf of users

Wallets may also decide to cover the cost of FIO Address for their users. For that purpose Foundation for Interwallet Operability has develop server code which enables the wallet to run their own registration server.

Enabling payments in other currencies

The FIO registration site allows wallets to integrate FIO Address and Domain registration via an API with payment occuring with common crypto currencies.

Sample UX

See In-wallet FIO Address registration