signtx (#31005)
#33765
Updates to documentation for External Signer.
signtransaction command is no longer primary mechanism.--stdin flag followed with stdin-content.signtx command followed by Base64-encoded PSBT.Best to squash commits when ready to merge.
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For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/33765.
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Possible typos and grammar issues:
<name> one of main, test, signet, regtest.” -> “With <name> being one of main, test, signet, regtest.” [missing verb phrase; current fragment is grammatically incomplete]2025-11-26
77@@ -78,6 +78,28 @@ Prerequisite knowledge:
78 * [Output Descriptors](descriptors.md)
79 * Partially Signed Bitcoin Transaction ([PSBT](psbt.md))
80
81+### Flag `--stdin` (required)
82+
83+Usage:
84+```
85+$ <cmd> --stdin
86+[…IPC interaction written to stdin…]
The term “IPC” could be confused with our multiprocess integration, maybe just use the wording from hwi --help:
--stdin Enter commands and arguments via stdin
90+
91+```
92+signtx "<Base64-encoded PSBT-content>"
93+```
94+
95+`signtx` indicates a PSBT signing request, followed by Base64-encoded PSBT-content. Quotes are optional, added in more recent versions. Semantically there is no difference, as Base64-encoded content is an uninterrupted sequence of characters regardless.
Afaik the use of quotes depends on the shell environment, I don’t think it’s worth documenting.
More important is to point out that Bitcoin Core will use --stdin here, in order to support large PSBTs.
119@@ -98,6 +120,8 @@ A future extension could add an optional return field `reachable`, in case `<cmd
120
121 ### `signtransaction` (required)
The original doc is wrong, there is only signtx, no signtransaction.
signtx and its arguments, like all other commands, can optionally be passed via --stdin
Is your comment that the doc is wrong, or that you moved away from that solution long ago? I only recently got involved with this side of Bitcoin, so I am really only familiar with v27+.
I can drop the signtransaction shell command for the sake obsolescence regardless, but it would be nice to know.
I don’t think there was ever a signtransaction, it was just a typo in the docs. The external signer feature was introduced in v22. The docs from that time mentions signtransaction and not signtx: https://github.com/bitcoin/bitcoin/blob/v22.0/doc/external-signer.md
Looking at the code from v22.0 however, the actual command was already signtx.
Good idea to update these docs.
Yes … I was inspired by a certain #31005 (comment)
84+```
85+$ <cmd> --stdin
86+[…command and arguments written to stdin…]
87+```
88+
89+#### stdin-command `signtx` (required)
signtx is not inherently stdin
All (required) commands should work with or without --stdin. Bitcoin Core currently only uses it for signtx, and that’s worth mentioning, but it can change.
Oookaaaaaay .. that changes things considerably. That was not at all clear to me.
Any chance you can drop a link to the place in source-code (assuming it is somewhat concentrated), such that I can have a quick peek. I could search myself, but I suspect you are familiar with the code-base.
Please use unique, descriptive commit message, or squash your commits according to https://github.com/bitcoin/bitcoin/blob/master/CONTRIBUTING.md#squashing-commits.
Also, there are a few LLM linter comments. Not sure if they all apply, but the missing a article makes sense.