SATD LETS A BITCOIN NODE DELETE OP_RETURN DATA — ITS AUTHOR SAYS DISK USE GOES UP — THE RELEASE NOTES SAY A REORG PAST A STRIPPED BLOCK FAILS

On November 2, 2026, at 20:30 UTC, satd’s author bkeroack announced on Delving Bitcoin that satd 0.7.0, released October 30, is “the first Bitcoin node implementation to allow optional full OP_RETURN value pruning.” It is off by default. Turned on, it zeroes OP_RETURN payloads of 4,096 bytes or more, or a size you pick, in blocks at least 288 deep. He cites what he calls the BIP-110 controversy. He thinks OP_RETURN data is a negligible share of mainnet, but wants operators to choose.

It won’t save you disk. His words: “The disk usage will go up, not down.” Punching a hole in a file frees only whole filesystem blocks, usually 4 KiB. The manual’s table shows 83-byte outputs free nothing, 210-byte outputs free nothing, and only something like a 100 KB output gets back about 96 KB. Each stripped transaction adds about 100 bytes of index. Nor is it a secure erase. He writes that SSDs leave the values “likely forensically recoverable,” and copy-on-write snapshots keep them.

The costs that matter more are in the release notes, not his post. A reorg that would disconnect a stripped block “fails, naming it, and changes nothing.” The node gives up script re-verification on -reindex for the inputs of stripped transactions. It stops being an archive peer, and the manual says flatly that “new nodes cannot sync the chain from it.” Blocks are still fully validated when they first arrive. And -restoreopreturns can download the stripped blocks back, from peers who kept them.

So this doesn’t touch the rules, and the data stays on the chain. In October, satd’s own manual said its filters can’t stop a transaction from confirming. Now a node can decline to relay the data and decline to keep it. The price is that it checks less of its own history and leans on others to hold what it threw away. Every operator who turns this on is betting that somebody else won’t. At the time of this writing, bitcoin was $77,507.