Sender Pending Fallback state by arminsabouri · Pull Request #1557 · payjoin/rust-payjoin

arminsabouri · 2026-05-14T18:32:44Z

Implementing @spacebear21 's idea from #1542 (comment)
for just the sender.

Recevier side is implemented here: #1558

Pull Request Checklist

Please confirm the following before requesting review:

I have disclosed my use of
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I have read CONTRIBUTING.md and rebased my branch to produce hygienic commits.

Claude made the updates to the payjoin-cli

coveralls · 2026-05-15T15:35:36Z

Coverage Report for CI Build 26187598484

Coverage decreased (-0.1%) to 85.14%

Details

Coverage decreased (-0.1%) from the base build.
Patch coverage: 28 uncovered changes across 3 files (23 of 51 lines covered, 45.1%).
1 coverage regression across 1 file.

Uncovered Changes

File	Changed	Covered	%
payjoin/src/core/send/v2/mod.rs	42	18	42.86%
payjoin-cli/src/app/v2/mod.rs	4	1	25.0%
payjoin-cli/src/app/v1.rs	1	0	0.0%

Coverage Regressions

1 previously-covered line in 1 file lost coverage.

File	Lines Losing Coverage	Coverage
payjoin-cli/src/app/v1.rs	1	69.33%

Coverage Stats


Relevant Lines:	13701
Covered Lines:	11665
Line Coverage:	85.14%
Coverage Strength:	394.85 hits per line

💛 - Coveralls

DanGould · 2026-05-19T12:56:34Z

concept ACK just like #1558

arminsabouri · 2026-05-19T17:42:51Z

+    /// Indicates that the fallback transaction has been broadcast and the session is complete.
+    pub fn broadcasted(
+        &self,
+    ) -> MaybeSuccessTransition<SessionEvent, (), std::convert::Infallible> {


std::convert::Infallible bc this method can never fail due to a API error.

TerminalTransition is more appropriate

xstoicunicornx

utACK c57d338

Somewhat strongly held nit: changing from SessionOutcome::Cancel to SessionOutcome::Aborted makes it more confusing/less intuitive. It gives two different terms that refer to the same state transition path. Was there a reason you felt that SessionOutcome::Aborted was better? I do think Cancelled is better than Cancel though.

Other than my nits and the comment that seems like it can be removed, implementation looks good and all tests pass.

spacebear21

Approach ACK, I have a couple of naming questions and a CLI ergonomics question (both also relevant for the receiver PR).

spacebear21 · 2026-05-20T17:33:07Z

-    /// Payjoin was cancelled by the user
-    Cancel,
+    /// Payjoin was aborted by the user
+    Aborted,


@xstoicunicornx I think this rename originated from my suggestion here to collapse the Cancel and Failure outcomes into one variant? The idea was that we can tell whether it was a failure or a cancel by looking at the session event log and seeing whether a Cancelled event occurred, vs. a Failed event. Then we wouldn't need the distinction at the SessionOutcome level.

@arminsabouri is this your understanding as well? Is the goal here with the rename to implement the rest of that idea in a follow-up?

yeah that was the idea. I am going to revert the naming change. I think this is best left as a follow up after this PR and maybe #1558

spacebear21 · 2026-05-20T17:46:17Z

        Ok(())
    }
+
+    async fn cancel_sender(&self, session_id: SessionId) -> Result<()> {


Since the cancel and fallback commands are so similar, I wonder if it would be more ergonomic to combine them into a single cancel command, which could either prompt the user for whether to broadcast the fallback, or default to fallback=true with an optional parameter to not broadcast.

Ack. If fallback=false, we can print the serialized tx. But cancel should ultimately close the session

If application manually cancels the assumption is they will not attempt to resume that session again. The session is marked closed. The cancel type leaves the session open and the session can only be closed once the user confirms they broadcasted the fallback tx -- or took an equivalent action.

Unifying them removes the two-command workflow: `cancel` now cancels the session and broadcasts the fallback transaction by default. Pass `--no-broadcast` to print the raw transaction hex instead for manual broadcast.

spacebear21

utACK 3bb4625

arminsabouri force-pushed the sender-cancel-state branch 2 times, most recently from 7cf2e7c to d3dac67 Compare May 15, 2026 15:31

arminsabouri force-pushed the sender-cancel-state branch from d3dac67 to cefae94 Compare May 15, 2026 16:21

spacebear21 mentioned this pull request May 15, 2026

Patch payjoin git URL in JS wasm manifest #1561

Merged

arminsabouri force-pushed the sender-cancel-state branch 4 times, most recently from 38ef7b3 to 402848a Compare May 18, 2026 15:58

arminsabouri changed the title ~~Sender cancel state~~ Sender Pending Fallback state May 19, 2026

arminsabouri force-pushed the sender-cancel-state branch from 402848a to b6040c7 Compare May 19, 2026 17:36

arminsabouri marked this pull request as ready for review May 19, 2026 17:37

arminsabouri commented May 19, 2026

View reviewed changes

arminsabouri force-pushed the sender-cancel-state branch from b6040c7 to c57d338 Compare May 19, 2026 17:55

xstoicunicornx approved these changes May 20, 2026

View reviewed changes

Comment thread payjoin-ffi/src/send/error.rs Outdated

Comment thread payjoin-ffi/src/send/mod.rs Outdated

Comment thread payjoin-ffi/javascript/test/unit.test.ts

spacebear21 requested changes May 20, 2026

View reviewed changes

arminsabouri force-pushed the sender-cancel-state branch from c57d338 to c338544 Compare May 20, 2026 19:04

arminsabouri added 2 commits May 20, 2026 16:19

Merge fallback into cancel command

3bb4625

Unifying them removes the two-command workflow: `cancel` now cancels the session and broadcasts the fallback transaction by default. Pass `--no-broadcast` to print the raw transaction hex instead for manual broadcast.

arminsabouri force-pushed the sender-cancel-state branch from c338544 to 3bb4625 Compare May 20, 2026 20:19

spacebear21 approved these changes May 20, 2026

View reviewed changes

spacebear21 merged commit b58af3f into payjoin:master May 20, 2026
23 checks passed

This was referenced May 20, 2026

WIP - sender fallback method #1543

Closed

Receiver fallback typestate #1558

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Coverage Report for CI Build 26187598484

Coverage decreased (-0.1%) to 85.14%

Details

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arminsabouri commented May 14, 2026 •

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