OP_Return

The data representing Runes is stored within the OP_RETURN field of a Bitcoin transaction.

OP_RETURN is an operation code (opcode) from Bitcoin’s scripting language that enables users to embed arbitrary data onto the blockchain. The official limit for data stored in an OP_RETURN field is 80 bytes, providing a dedicated space for storing information related to Runes.

The official Runes documentation provides detailed explanations and guidelines on the specific usage and formatting of OP_RETURN outputs for representing Runes data. This documentation serves as a valuable resource for developers and users interested in understanding and implementing the Runes Protocol within the Bitcoin ecosystem.

By utilizing the OP_RETURN field, the Runes Protocol can seamlessly integrate fungible token data into regular Bitcoin transactions, without modifying the core Bitcoin protocol or introducing external dependencies.

This approach aligns with the ethos of Bitcoin's decentralized and open-source nature, allowing for innovative applications and use cases to be built on top of the existing infrastructure.