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Upgrading Your Appchain Runtime with Sudo


Sudo is a module that enables privileged runtime calls to be dispatched when called from the Sudo account. Sudo is sometimes colloquially referred to as a superuser or god-like account. This enables you to perform privileged actions in the course of managing your appchain, such as upgrading your Tanssi appchain's runtime.

In this guide, you'll learn how to use Sudo to upgrade your Tanssi appchain's runtime. With Sudo access, upgrading your chain is a quick and easy process. Note that appchain teams in production will have the option to phase out Sudo access and rely on governance to process runtime upgrades.

Checking Prerequisites

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

  • A Tanssi appchain (Snap or Dedicated)
  • Your appchain's Sudo account connected to your appchain's Polkadot.js Apps. You can refer to the Managing Sudo guide for instructions on injecting your Sudo account into Polkadot.js Apps

If you're unsure what your Tanssi appchain's Sudo account is, you can find it in your Tanssi Dashboard underneath the Properties section.

Locating your Sudo address on


You should always protect your Sudo account key with the utmost security precautions, as it grants privileged access to your Tanssi appchain.

Upgrading Your Runtime

To get started, head to Polkadot.js Apps for your Tanssi appchain. The Polkadot.js Apps link for your Tanssi appchain can be found in your Tanssi Dashboard underneath the Tooling section.

Locating your Polkadot.js Apps Link on

Prior to the upgrade, you'll need to have the Wasm runtime ready to upload. You'll also need to have your Sudo account accessible in Polkadot.js Apps. Then, take the following steps:

  1. Navigate to the Developer Tab of Polkadot.js Apps for your Tanssi appchain
  2. Click on Sudo. If you do not see Sudo in this menu, then you have not associated the Sudo account with Polkadot.js Apps. Make sure that your Sudo account is injected by your wallet and connected to Polkadot.js Apps
  3. Select the system pallet
  4. Select setCode
  5. Toggle the fileUpload switch to enable uploading your Wasm runtime file
  6. Upload your Wasm runtime
  7. Press Submit Sudo and confirm the transaction in your wallet

Upgrading your Runtime on Polkadot.js Apps

You can verify that your runtime upgrade was successful by checking the runtime version in the upper left-hand corner. In this case, we can see that the Tanssi appchain's runtime was successfully upgraded to version 400.

Check Runtime version on Polkadot.js Apps

And that's it! The Using Sudo section has plenty more guides on how you can use the Sudo account to manage your Tansi appchain.

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Last update: March 19, 2024
| Created: March 13, 2024