# Requesters and Sponsors
As a developer it helps to understand what a requester is and what a sponsor does. They are both important parts of the Airnode ecosystem. This doc will further define them and walk you through the process to derive a sponsor wallet and to sponsor a requester using the admin CLI commands.
# What is a Requester?
The term requester is important to remember. When requester is mentioned, the reference is to your smart contract that calls an Airnode.
As an example see the
myContract.sol contract in the diagram within the
Overview doc, it is a requester.
# What is a Sponsor?
Equally important is the term sponsor. A sponsor is an entity such as yourself, an organization, etc. Sponsors create relationships between requesters and Airnodes.
# Sponsor's Requester/Airnode Relationships
As a sponsor you will use the address of an Ethereum account (called a
sponsorAddress) from a digital
wallet you own to "sponsor a requester" and then with the same
sponsorWallet" for an
Airnode. This action creates a relationship between a sponsor's requester and a
particular Airnode. You do this because a sponsor is the entity that pays for
the fulfillment of a request, the gas costs the Airnode will incur. These costs
will be withdrawn from the
sponsorWallet of the Airnode when the requester
In the diagram below a sponsor uses a mnemonic to sponsor a requester with the
Admin CLI. The CLI will use the default address of the mnemonic as the
sponsorAddress for the sponsorship. Next the sponsor will derive a
sponsorWallet for an Airnode using the same
Because the requester was sponsored with the same
sponsorAddress that was used
to derive the
sponsorWallet of the Airnode, the requester can now make
requests of the Airnode.
In the above diagram it is possible to use the same sponsorAddress
(0xF4...dDyu9) to derive other sponsor wallets for other Airnodes. And it is
possible to sponsor more than one requester with this same sponsorAddress.
However it is important to remember that all requesters can now access all the
Airnodes regardless if they need to. There is no harm in this scenario.
# Advanced Scenarios
Two requesters sponsored with the same sponsorAddress
(0xF4...dDyu9)could access the same Airnode having a sponsor wallet derived by sponsorAddress
Using two separate sponsorAddresses (from two different Ethereum accounts), you can derive two separate sponsor wallets for the same Airnode, say
(0xG9...fFzc5). Then you can sponsor one requester each with
(0xF4...dDyu9)and the other with
(0xG9...fFzc5). Now each requester will deplete funds from a separate sponsor wallet.
You have derived two sponsor wallets for two different Airnodes using different sponsorAddresses, say
(0xG9...fFzc5). You have one requester that needs to makes requests from each Airnode. Simply sponsor the requester twice with both sponsorAddresses.
# Things to Remember
When you sponsor a requester with a sponsorAddress, you are giving it permission to use the sponsor wallet associated with the Airnode (created with the same sponsorAddress).
When the requester makes a request to the Airnode, the Airnode will use funds from the corresponding sponsor wallet to pay gas costs in response to the request. Therefore the sponsor pays for the fulfillment of the request.
# Admin CLI Commands
There are several sponsor and requester related commands in the
Admin CLI Commands package. You
can also see a list of available commands using
npx @api3/airnode-admin --help.
In the next two sections of this doc you will use two commands from the @api3/airnode-admin package to sponsor a requester and to derive a sponsor wallet.
sponsor-requestersponsors a requester.
derive-sponsor-wallet-addresscreates a sponsor wallet associated with an Airnode.
# How to Sponsor a Requester
When a sponsor uses the same
sponsorAddress to "sponsor a requester" and to
"derive a sponsor wallet" for an Airnode, the requester will have permission to
make requests to the Airnode on behave of the sponsor. This allows the sponsor
to cover the gas costs incurred by the Airnode when responding to the request.
Sponsors need to keep their sponsor wallets topped off if they want Airnodes to
fulfill requests made by their requesters. However this does not cover the cost
of API data that the Airnode serves, see
API Provider Fees.
To sponsor a requester execute the
sponsor-requester command using the
parameters detailed in the list below. Your requester should already be deployed
on-chain. This command has transaction gas costs.
providerURLA blockchain provider URL (such as Infura) with providerID for the desired network.
mnemonicUsed for gas costs to fund the sponsorship and used to derive the
sponsorAddressfrom the default address. The
sponsorAddresswill be needed to derive a
sponsorWalletfor an Airnode.
requesterAddressThe address of the requester contract.
sponsor-requester will return the requesterAddress and
# How to Derive a Sponsor Wallet
To use a particular Airnode you must derive a sponsor wallet. Once the sponsor
wallet is created it must be funded using the public address returned by the
derive-sponsor-wallet-address. Each Airnode keeps a separate list of
individual sponsor wallets that can access the Airnode. Learn more about
To derive a sponsor wallet for an Airnode execute the
derive-sponsor-wallet-address command using the parameters detailed in the
list below. There are no transaction gas costs to do so.
providerURLa blockchain provider URL (such as Infura) with providerID for a desired network
airnodeof address the desired Airnode
sponsorthe sponsorAddress (an address of an Ethereum account) owned by a sponsor
derive-sponsor-wallet-address will return the public address of
the sponsor wallet to be funded by the sponsor.
If you forget the public address of the sponsor wallet simply run
derive-sponsor-wallet-address again. Since the wallet already exists for the
airnodeAddress/sponsorAddress pair it will just return the address.
Designated Sponsor Wallets
Sponsors should not fund a
sponsorWallet with more then they
can trust the Airnode with, as the Airnode controls the private key to the
sponsorWallet. The deployer of such Airnode undertakes no
custody obligations, and the risk of loss or misuse of any excess funds
sent to the
sponsorWallet remains with the sponsor.
# Record Keeping
During and after deriving a sponsor wallets and sponsoring requesters there are a few things to keep track of.
|requesters||Record which |
|sponsor wallets||Record which |
|sponsor wallets||Record the |
You can acquire the public address of a sponsorWallet later, if you loose it, by
running the command
derive-sponsor-wallet-address again. Since the
sponsorWallet was already created for the sponsorAddress/airnodeAddress pair,
the command will only return the public address for the wallet. However you must
use the same sponsorAddress used when the wallet was first created or a new
sponsorWallet will be created.