Block Production Services Payment¶

Introduction¶

As presented in the Block Production as a Service article, there are two main costs associated that the appchain governor must cover:

• Block producers assignment - for the assignment of block producers by the Tanssi protocol, which happens once per session
• Block production - for each block that is produced on the appchain's behalf

In this guide, you'll learn how to use the Tanssi dApp to top-up your account and keep your appchain's liveness.

Checking Prerequisites¶

For the examples in this guide, you will need to have the following:

• A Tanssi appchain (Snap or Dedicated)
• The account you used when registering the appchain, imported in any of the supported wallets

If you're unsure what your registration account is, you can query it directly from the Tanssi orchestrator chain, which keeps records of every registered appchain. To do so, head to the Chain state section on the Polkadot.js Apps connected to the orchestrator chain for snap appchains or dedicated appchains, and take the following steps:

1. Select the registrar storage module
2. Select registrarDeposit
3. Insert your appchain ID
4. Press + icon

You'll see the registration account at the bottom.

Topping-Up Your Appchain's Credits¶

Following a pay-as-you-go model, the appchains must have funds allocated to pay for the services, which, in time, will be deducted by the Tanssi protocol upon every session change for the cost of block producer assignment and every block for the cost of producing the block.

Tanssi reserves a fraction of the payments received for the protocol's treasury, and the remainder is burnt. This is the current configuration:

20%

You can check your appchain's current balance and top it up using the Tanssi dApp. To do so, head to the Tanssi dApp and connect the appchain's registration account to the dApp. The site will display a card showing your appchain status. This card includes the projected liveness forecast underneath the Block Production section and the Top Up button.

Clicking on the Top Up button displays a sidebar where the following information can be seen:

• Current balance - the current balance allocated for the appchain's block production service
• Available balance - the balance available in the appchain's registration account, which is connected to the dApp
• Current cost - current cost per block producer's assignment and cost per block
• Projected forecast - the estimated day when the appchain runs out of funds and stops being served

To extend the appchain's projected runway, take the following actions:

1. Insert the amount of tokens to buy block production services
2. Click Top Up

You will be asked to sign the transaction, and after it's gone through, your appchain will benefit from an extended horizon of liveness.