An unknown actor embedded the complete text of the U.S. Constitution onto the Bitcoin blockchain on May 28, 2026, using an OP_RETURN output field in a transaction confirmed at 8:25 p.m. UTC. The inscription cost 113,454 satoshis, equivalent to $83.41, and occupied 44.4 kilobytes within the network.
The transaction was broadcast Thursday evening and processed by SpiderPool mining pool within 14 minutes of transmission. According to Bitcoin Magazine’s Micah Zimmerman, the inscription leverages SegWit and Taproot features alongside expanded OP_RETURN capacity, marking a notable use case for the opcode’s evolved technical capabilities.
OP_RETURN Evolution and Technical Context
OP_RETURN is a Bitcoin script opcode that permits arbitrary data attachment to transactions. Outputs created with OP_RETURN are provably unspendable and carry no bitcoin value, making them suitable for metadata, proofs, and document anchoring without affecting the monetary layer.
Historically, the OP_RETURN field was capped at 80 bytes, restricting use to short hashes, timestamps, and brief messages. Bitcoin Core v30, released mid-2025, removed both the byte limit and the one-OP_RETURN-per-transaction restriction. Developers argued the old cap was counterproductive; users had already found workarounds, and the restriction created more problems than it solved.
The Constitution inscription contains the full text, beginning with “We the People of the United States” and including all seven Articles and 27 Amendments. At 44.4 kilobytes, the data volume would have been impossible under the previous 80-byte constraint.
Prior Document Anchoring and Ordinals Protocol
The Constitution inscription follows years of experimentation with blockchain-based document verification. Projects including OpenTimestamps, DOCPROOF, and Factom anchored document hashes to Bitcoin, creating permanent cryptographic proof of existence at specific points in time. The Ordinals protocol, launched in 2023, extended this approach by inscribing images, audio, and code directly into witness data, treating the blockchain as immutable storage.
The Constitution transaction represents the first known use of expanded OP_RETURN to embed a full-length text document rather than a hash or compressed reference.
Ongoing Debate Over OP_RETURN Limits
The inscription has emerged amid active debate over Bitcoin’s data storage role. BIP-444, a pending proposal, seeks to restore the OP_RETURN cap at 83 bytes. Backers of the proposal argue that unlimited data storage undermines Bitcoin’s identity as a monetary network and risks bloating the blockchain with non-financial metadata.
Developers who removed the restrictions counter that the old cap was ineffective and that users will always find alternative methods to anchor data, making the limitation more disruptive than permissive. The Constitution inscription, at 44.4 kilobytes, illustrates the scale of data now possible under the current ruleset.
The identity of the actor who inscribed the Constitution remains unknown, as does the specific intent behind the choice of document.
