Grok, what is bCore v30?
“Bitcoin Core 30 (often abbreviated or referred to casually as “bcore 30” or similar in discussions) is the major version release of Bitcoin Core, the primary open-source reference implementation software that powers Bitcoin nodes.
Bitcoin Core v30.0 was released in October 2025 (with subsequent patches like 30.1 and 30.2 addressing bugs). It’s a significant update that includes several changes, but the most controversial and widely discussed one is the dramatic increase in the default OP_RETURN data limit.
Key Change in v30
• Previously, OP_RETURN (a way to embed small amounts of arbitrary/non-spendable data in Bitcoin transactions) was limited to 80 bytes by default in node mempool policy.
• In v30, this limit was massively expanded — reports vary slightly in exact figures due to implementation details and maximums, but it effectively allows up to ~100,000 bytes (or in some descriptions nearly the full ~4 MB block size limit) for OP_RETURN outputs by default.
• This change removes long-standing restrictions that were intended to discourage “spam” or non-monetary data on the blockchain (e.g., inscriptions, arbitrary files, or protocols like those seen in Ordinals/BRC-20).”