September 29, 2025|zkVerify

From Testnet to Mainnet: Ship Proofs Faster with the Relayer API

We are very excited to announce the launch of the Relayer API into mainnet. First off, we want to extend a big Thank You to all our supporters on testnet that are building zk-apps utilizing the Relayer for proof submissions. As we enter the next major phase of our product, we encourage everyone to follow this guide below to port your testnet zk-app to mainnet, and continue sending proofs via the Relayer. Both testnet and mainnet are accessible

Important Links

Mainnet

•
Relayer API - Mainnet: https://relayer-api-mainnet.horizenlabs.io/api/v1
•
Create an API key in Mainnet: relayer.horizenlabs.io
•
API Documentation: https://relayer-api-mainnet.horizenlabs.io/docs
•
Guide: https://docs.zkverify.io/overview/getting-started/relayer

Testnet

•
Relayer API - Testnet: https://relayer-api-testnet.horizenlabs.io/api/v1
•
Create an API key in Testnet: https://relayer-api-testnet.horizenlabs.io/api/v1
•
API Documentation: https://relayer-api-testnet.horizenlabs.io/docs
•
Guide: https://docs.zkverify.io/overview/getting-started/relayer

Next Steps

  1. For current testnet users that intend to keep their zk-app running on testnet, update the Relayer API testnet URL to: relayer-api-testnet.horizenlabs.io
    1. While the current link https://relayer-api.horizenlabs.io still points to testnet, we plan to deprecate this testnet link shortly after
  2. For current testnet users that will be deploying their zk-app to mainnet, make sure you are using the correct mainnet API link indicated above. You will also need to generate a new API key for use in mainnet.
    1. Mainnet API URL: https://relayer-api-mainnet.horizenlabs.io
    2. Note that verification keys registered in testnet will automatically be re-registered in mainnet, so users will not need to re-register the same verification key from testnet.
  3. New and current users can access both testnet and mainnet environments. Ensure that you are using the correct links and portal to create an API key. You will need to sign up with an email and verify your email address. Once your email address is verified, you can login to your account to generate an API key.

Support

Reach out to us on Discord or send us an email describing the issue/ codebase links/ screenshots to relayer-support@horizenlabs.io