Asset Hub Migration: What Developers Need to Know About Polkadot's Relay Chain Transition

What Is the Asset Hub Migration?

The Asset Hub migration refers to the transfer of core user-facing functionality—balances, staking, and governance—from the Polkadot Relay Chain to the Asset Hub system parachain. This is part of Polkadot's long-term roadmap to reduce the Relay Chain's workload and improve scalability.

The migration was executed on Kusama on October 7, 2025, and on Polkadot on November 4, 2025. It was performed via runtime upgrades, meaning no hard fork or user intervention was required. Funds and accounts were automatically moved to the Asset Hub without any action from end users.

• Balances: All DOT/KSM balances are now managed on Asset Hub. The Relay Chain no longer tracks individual account balances.
• Staking: Staking operations (nominate, bond, unbond) are now handled on Asset Hub. Existing nominations and bonded funds were migrated automatically.
• Governance: Voting, delegation, and treasury proposals are now processed on Asset Hub. The Relay Chain retains only consensus and interoperability functions.

Why Is the Migration Happening?

The Relay Chain originally handled all network functions, but as Polkadot grew, this became a bottleneck for upgrades and scalability. By moving balances, staking, and governance to Asset Hub, the network achieves several key improvements.

Asset Hub is a specialized parachain designed for asset management and user interactions. It offers lower fees, a reduced existential deposit (0.01 DOT vs 1 DOT), and support for multiple asset types including stablecoins and NFTs. The migration also paves the way for the JAM (Join-Accumulate Machine) architecture, which will further modularize Polkadot's compute and staking models.

• Reduced Relay Chain state bloat, enabling faster block production and simpler upgrades.
• Faster and safer network upgrades, as changes to user-facing features no longer require Relay Chain runtime upgrades.
• Improved developer experience with a unified platform for asset management and smart contracts.
• Lower barriers for end users with reduced fees and existential deposits.

What Changes for Developers?

For developers, the most significant change is that queries for balances, staking, and governance data must now be directed to the Asset Hub chain instead of the Relay Chain. This affects RPC endpoints, indexers, and any application that reads on-chain state.

The Asset Hub uses the same Substrate-based API as the Relay Chain, so existing code that uses polkadot-js or Substrate API Sidecar can be adapted by changing the chain endpoint. However, some storage items and extrinsics have moved, so you may need to update your code to reference the new pallet locations.

• Update RPC endpoints: Use the Asset Hub's WebSocket endpoint (e.g., wss://polkadot-asset-hub-rpc.polkadot.io) for balance, staking, and governance queries.
• Check storage keys: Storage items for System.Account, Staking, and Governance have moved. Use the correct pallet prefixes for Asset Hub.
• Test on Kusama: Kusama's migration is complete and can serve as a testbed for your application's compatibility.
• Monitor runtime upgrades: Future upgrades to Asset Hub will not affect the Relay Chain, but you should subscribe to Asset Hub runtime events.

How to Update Your RPC Endpoints

To ensure your dApp continues to function after the migration, you must update the RPC endpoints used for balance, staking, and governance queries. The Relay Chain endpoint (e.g., wss://rpc.polkadot.io) should still be used for consensus and interoperability data, but user-facing data now lives on Asset Hub.

If you are using OnFinality's RPC services, you can simply switch to the Polkadot Asset Hub endpoint. OnFinality provides both public and dedicated endpoints for Asset Hub, ensuring low-latency access and high availability. For production applications, consider using a dedicated node to guarantee performance and avoid rate limits.

• Use wss://polkadot-asset-hub-rpc.polkadot.io for Polkadot Asset Hub.
• Use wss://kusama-asset-hub-rpc.polkadot.io for Kusama Asset Hub.
• Update your polkadot-js API initialization to point to the Asset Hub endpoint for relevant queries.
• For indexers and backend services, configure separate connections for Relay Chain and Asset Hub as needed.

Impact on Infrastructure Providers

Infrastructure providers must ensure their nodes support the Asset Hub runtime and that they offer reliable endpoints for both the Relay Chain and Asset Hub. The migration does not require new node software, but node operators should upgrade to the latest runtime that includes Asset Hub support.

For RPC providers like OnFinality, this means maintaining separate endpoint URLs for Asset Hub and ensuring that load balancers and caching layers are configured correctly. Providers should also monitor for increased traffic to Asset Hub endpoints as dApps migrate their queries.

• Run Asset Hub nodes alongside Relay Chain nodes to serve both sets of endpoints.
• Update documentation to reflect new endpoint URLs for Asset Hub.
• Test failover and redundancy for Asset Hub endpoints before the migration date.
• Communicate changes to customers well in advance to minimize disruption.

Testing and Validation

Before the Polkadot migration, extensive testing was conducted on Kusama. Developers are encouraged to test their applications on Kusama Asset Hub to ensure compatibility. The Kusama migration is already complete, so you can validate your code against a live environment.

Key areas to test include: balance retrieval, staking operations (bond, nominate, unbond), governance voting, and any custom queries that rely on Relay Chain storage. Use the Kusama Asset Hub endpoint and compare results with pre-migration behavior.

• Set up a test environment using Kusama Asset Hub endpoints.
• Run integration tests for all user-facing features that involve balances, staking, or governance.
• Verify that your application correctly handles the new existential deposit and fee structure.
• Check that your monitoring and alerting systems are updated to track Asset Hub metrics.

Frequently Asked Questions

Here are answers to common questions about the Asset Hub migration.