OP_CAT to BIP 0003 format, add usecase and test vectors

EthanHeilman commented at 0:40 am on January 24, 2026: contributor

Add two use cases to motivation
Add BIP 003 versioning
Test vectors

EthanHeilman marked this as a draft on Jan 24, 2026

EthanHeilman force-pushed on Jan 24, 2026

OP_CAT to BIP 0003 format, add usecase e681ec8739

EthanHeilman force-pushed on Jan 24, 2026

in bip-0347.mediawiki:115 in e681ec8739

109@@ -106,6 +110,16 @@ An alternative implementation of OP_CAT can be found in Elements <ref>Roose S.,
110 
111 <references/>
112 
113+==Changelog==
114+
115+* __0.3.1   (2026-01-23) - Made compliant with BIP 003, use cases added.

murchandamus commented at 11:38 pm on January 25, 2026:

Not an issue, just fyi: this was already BIP 3 compliant as the preambles of all BIPs were updated by #1820, and the Changelog section and Version header are only required when a BIP is changed after it has been advanced to Complete.

murchandamus commented at 11:40 pm on January 25, 2026: member

If you have have concluded all planned work on this proposal, have you considered advancing this BIP to Complete?

murchandamus added the label BIP update by author on Jan 25, 2026

EthanHeilman commented at 4:47 pm on January 26, 2026: contributor

@murchandamus From a content perspective, I don’t plan to add anything else. If @arminsabouri agrees, I see no reason not to mark it as complete.

If at some future point, in response to rough consensus we may create an activation client, I plan to document the activation details in this BIP. Rereading BIP 0003, it doesn’t say it explicitly, but it seems like the intention is for this to be done after the BIP is complete as part of preparing the BIP for deployed status. I’m I understanding BIP 0003 correctly here?

arminsabouri commented at 9:26 pm on January 26, 2026: contributor

Ack e681ec8739b8ed155bba64229201711b9205b975

murchandamus commented at 10:37 pm on January 26, 2026: member

Ethan wrote:

If at some future point, in response to rough consensus we may create an activation client, I plan to document the activation details in this BIP. Rereading BIP 0003, it doesn’t say it explicitly, but it seems like the intention is for this to be done after the BIP is complete as part of preparing the BIP for deployed status. I’m I understanding BIP 0003 correctly here?

You’re right, there is so far no explicit guidance regarding when the activation mechanism would be expected or how it should be formatted. Given that any deployment strategy matters only temporarily and doesn’t otherwise impact the content of the Specification, it seems reasonable to me that the activation mechanism may be added after a BIP is moved to Complete.

draft --> complete 440bcf7c9d

EthanHeilman marked this as ready for review on Feb 2, 2026

in bip-0347.mediawiki:12 in 440bcf7c9d

 8+  Status: Complete
 9   Type: Specification
10   Assigned: 2023-12-11
11   License: BSD-3-Clause
12   Discussion: 2023-10-21: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2023-October/022049.html [bitcoin-dev] Proposed BIP for OP_CAT
13+  Version: 0.3.1

murchandamus commented at 0:08 am on February 3, 2026:

Bumped to 1.0.0 below:

0  Version: 1.0.0

in bip-0347.mediawiki:69 in 440bcf7c9d

murchandamus commented at 0:08 am on February 3, 2026:

Do you feel that this proposal needs test vectors? If so, they should be added/referenced for it to be moved to Complete. The Elements implementation does appear to have some that could perhaps be adapted: https://github.com/ElementsProject/elements/pull/495/changes/9fea017cf6b7b0e78c45df347a46cea34f37c82b

EthanHeilman commented at 0:14 am on February 3, 2026:

Good point! The reference implementation does have test vectors. I’ll update this PR with them when I get a moment

murchandamus commented at 0:40 am on February 3, 2026:

Great thanks!

Update bip-0347.mediawiki

Co-authored-by: Mark "Murch" Erhardt <murch@murch.one>

2bdb6b2aef

BIP347: Update table entry to complete db1e7c3de0

murchandamus commented at 10:35 pm on February 27, 2026: member

I noticed that the table entry was not updated along the preamble update, so I added a commit to fix the table entry.

murchandamus added the label PR Author action required on Feb 27, 2026

Merge branch 'bitcoin:master' into catupdate db2e32ec4c

Fix breaking test afe6b73f55

EthanHeilman force-pushed on Mar 2, 2026

Add test vectors b6959a3e2e

EthanHeilman force-pushed on Mar 2, 2026

EthanHeilman renamed this:
~~OP_CAT to BIP 0003 format, add usecase~~
OP_CAT to BIP 0003 format, add usecase and test vectors
on Mar 2, 2026

EthanHeilman commented at 2:30 pm on March 2, 2026: contributor

@murchandamus Added test vectors

murchandamus commented at 3:30 pm on March 2, 2026: member

Thanks, looks good

murchandamus merged this on Mar 2, 2026

murchandamus closed this on Mar 2, 2026

murchandamus removed the label PR Author action required on Mar 5, 2026

OP_CAT to BIP 0003 format, add usecase and test vectors #2090