Synchronizer Registration

To register as a Synchronizer, you need to complete two steps:

1. Register for the whitelist via GitHub.

2. Add an OP_RETURN to the coinbase transaction.

Register for the whitelist via GitHub

Provide the following information to exSat by submitting an issue on this GitHub repository:

• Your mining pool name

• Synchronizer account (Created here)

• Reward address (an EVM address receives the XSAT rewards)

Once exSat verifies your informations, your Synchronizer account will be added to the whitelist. Only Bitcoin miners on this whitelist who include an OP_RETURN in the coinbase transactions of their mined blocks can submit Bitcoin block data to the exSat network.

Below is a template for the issue submission, using sample data:

Issue Title:[Mining Pool's Name]Submit mining pool registration information 

Content:
Please provide the following information for Synchronizer.

Registration info:
*Mining pool name: cool pool
*Synchronizer Account: coolpool.sat
Reward Account: 0xee37064f01Ec9314278F4984fF4B9B695EB91912

Display info in Frontend:
*Name: CoolPool
*Logo url: https://cool.network/img/logo.png
Homepage url: https://coolpool.com
Introduction: A cool pool.

All information marked with an asterisk (*) is required.

Logo Supports PNG and SVG. The recommended minimum size for Logo is 128*128 pixels and the file size should be less than or equal to 1MB. Otherwise, the image will not be merged, and a comment will be left to remind the user to re-upload the logo.

Please use a version of your logo that is clearly visible against a black background.

If you didn't supply reward account in the "Registration info" part, you could also configure the reward account via running the client.

Why is Manual Assistance Required for Synchronizer Registration?

The number of Bitcoin mining pools that meet exSat’s requirements is limited, and these are typically well-established, reputable pools. To become a Synchronizer, mining pools must include specific OP_RETURN data in the coinbase transactions of the Bitcoin blocks they mine—an essential step for completing registration.

Synchronizers are vital to the security and stability of the exSat network. As such, the exSat team works closely with mining pools interested in becoming Synchronizers. This collaboration ensures that all technical preparations are completed and that the pools are fully equipped to perform Synchronizer duties effectively.

Register on-chain via OP_RETURN

The exSat network needs to verify the following information during its operation:

1. Whether a Synchronizer has mined any Bitcoin blocks within the most recent 432 blocks, thereby qualifying as a Qualified Synchronizer.

2. If a Bitcoin block is mined by a specific Synchronizer, that Synchronizer could receive up to 20% of the rewards for that block.

To enable this verification, Synchronizers must include a unique OP_RETURN marker in the coinbase transaction of the Bitcoin blocks they mine. This marker identifies the block as being mined by the Synchronizer. The format of the OP_RETURN is as follows:

OP_RETURN + LENGTH + EXSAT + VERSION + SYNCHRONIZER ACCOUNT

• OP_RETURN: 0x6a

• LENGTH: 1 byte, 0x12, the total length (in bytes) of the content excluding OP_RETURN and LENGTH

• EXSAT: 0x4558534154 (UTF-8 encoding)

• VERSION: 0x01

• SYNCHRONIZER ACCOUNT: The account registered at this step. For example, if the account name is xsatsync.sat, the encoded content would be: 1712001312180d021f120013. Link of the reference code to this for encoding and decoding.

Example:

Concatenate the above content to obtain: 6a124558534154011712001312180d021f120013

Refer to an on-chain transaction:http://mempool.regtest.exactsat.io/zh/tx/98ddd977f8b350455e26f6e2646a4fcad86d682a520f31ddfbe6e8268f6eefe

Online Tool : Here is a online tool that can help you quickly generate the content of OP_RETURN. You just need to enter your exsat synchronizer account to get the complete OP_RETURN content.

For example, if you enter xsatsync.sat and click the "Generate OP_RETURN content" button, the complete OP_RETURN encoded content will be generated: 6a124558534154011712001312180d021f120013.