Bringing Hybrid Custody to Mainnet

We’re excited to announce a major step forward with Hybrid Custody on Flow as we have enabled AuthAccount Capabilities on Mainnet. The FLIP for this feature has now been accepted and we’re thankful to everyone in the community that has provided thoughtful and constructive feedback as it has been incredibly helpful in shaping the approach.

Since AuthAccount Capabilities were enabled on Testnet several weeks ago, it’s been exciting to see developers already begin to embrace this new concept as they leverage Hybrid Custody to build mainstream-ready experiences. At the Flow Hackathon, we’ve seen over 40% of the submissions building these new experiences on Testnet - and now these developers have the path to bring their products to Mainnet.

While the release of AuthAccount Capabilities on Mainnet is a major milestone towards Hybrid Custody, we’re continuing to finalize a series of additional components that will round out the entire set of resources for developers building these new experiences. Below we’ll outline what you can expect today and what will be available in the coming weeks.


  • We’ve enabled AuthAccount Capabilities on Mainnet today as part of our height-coordinated upgrade in order to have it in place as we finalize the AuthAccount Capabilities Management Standard. This standard is a critical part of the solution so that we can ensure interoperability across the Flow ecosystem.
  • With the feature enabled today, developers can choose to begin building experiences that leverage AuthAccount Capabilities, enabling apps to give a user’s delegated access to app accounts. We recommend developers closely follow the developments in the AuthAccount Capabilities Management Standard as they design and develop these experiences so users can view and manage their linked accounts & the assets within their linked Hybrid Custody accounts.
  • The current proposed standard is deployed to Testnet as the community continues to iterate towards a flexible and secure Hybrid Custody model that works for all stakeholders. Developers can look to the onflow/linked-accounts repo and deployed LinkedAccounts contract to build on local and Testnet environments.

After standard is finalized

  • We expect to finalize the AuthAccount Capabilities Management Standard FLIP based on remaining feedback and reviews from the community. Once this FLIP is accepted, we will deploy the finalized LinkedAccounts contract to Mainnet and developers can begin to use this standard in their apps.
  • We’ll provide a migration guide for developers that have built against the original standard on Testnet in order to bring pre-existing implementations in line with the finalized standard.
  • We’ll provide a scaffold in the Flow CLI that will enable developers to get started with the LinkedAccounts contract and all related transactions.

Input and feedback

We’d love the community to continue providing crucial input and feedback to shape these solutions and wanted to call out a few specific areas where you can help:

We’ve also created a new channel for Hybrid Custody in the Flow Discord as a place for questions, comments, and feedback as well - so feel free to join us there as well.