Weekly Check-in: Week of 2026-05-04

[payjoin-bot]

Weekly standup — each contributor has a thread below with auto-gathered activity.

Reply to your thread by end-of-day Monday (your timezone). Copy the template below and fill it in:

### Shipped
<!-- Add anything the bot missed: design work, specs, conversations, off-GitHub contributions. Correct any mistakes. Skip if the bot covered everything. -->

### Focus
What are you working on this week?

### Bottleneck
What is the single biggest bottleneck in progress toward your greater goal?
Name your goal. Name the constraint. Name who or what can unblock it.

Participated: @DanGould, @spacebear21, @arminsabouri, @chavic, @zealsham, @Mshehu5

[payjoin-bot]

DanGould

@DanGould

Shipped

PRs reviewed:

• Document OHTTP relay random selection guidance

Last Week

Review your previous thread: Last week's thread

[DanGould]

Shipped

• got Upgrade payjoin SatoshiPortal/bullbitcoin-mobile#2041 in a ~tests passing state. Back and forth with spacebear went well https://github.com/DanGould/bullbitcoin-mobile/tree/upgrade-payjoin
• Wrote a monthly letter
• decision to go in the direction of Update Dart fetchOhttpKeys to support https #1500
• Async Check-in review. We're going to keep it but need to get the bot to post raw links.

Focus

• Get Upgrade payjoin SatoshiPortal/bullbitcoin-mobile#2041 merged
• Taxes v2
• Lugano date by eow

Bottleneck

• I need an update from @spacebear21 when he signs off each day so that I can pick up the bull bitcoin mobile integration until it's merged
• Getting to payjoin v1 and getting these integrations out is bottlenecked on our reference implementation (e.g. decisions about fallback handing in Liana). There are a handful of lingering issues to address immediately after bull bitcoin mobile gets bottlenecked on review from their side. The reference itself is slightly bottlenecked by triage of remaining issues and payjoin v1 that's blocked by them. We're 🤏 this close. End-of-May goal IMO.

[payjoin-bot]

spacebear21

@spacebear21

Shipped

PRs reviewed:

• parallelize FFI language binding tests in contrib/test.sh

Last Week

Review your previous thread: Last week's thread

[spacebear21]

Focus

• BBM upgrade
• JS bindings fixes for a shippable npm package

Bottleneck

• review and merge Update Dart fetchOhttpKeys to support https #1500. I've skimmed the code for basic sanity, and confirmed this actually works in BBM tests, but I have not thoroughly reviewed the logic or audited line-by-line as this is too low-level for me to do properly in a realistic time frame.

[payjoin-bot]

arminsabouri

@arminsabouri

Shipped

PRs merged:

• Fix unused results in session unit tests
• Mmap index files

PRs reviewed:

• Exclude OP_RETURN outputs from change identification heuristics

Issues opened:

• Source nodes that produce TxSet clone and hash the entire vec of u32s
• LRU cache dense get_tx

Last Week

Review your previous thread: Last week's thread

Auto-detected signals:

• PR awaiting review: Avoid deep clone when combining single facts
• PR awaiting review: Demo sender fallback
• PR has requested changes: Add honest & semi-honest overview

[arminsabouri]

Focus:

• Demo sender fallback #1510
• Resurrecting psbt-crdt. Spec writing and coding. By eow hoping to have a POC / refrence implementation. This will be a POC of multi party tx construction in the honest settings using very minimal if any transport mechanism.
• Finish up honest overview document. Add honest overview multiparty-protocol-docs#4 . Semi honest will follow up in a seperate PR.

Blockers:

• Bouncing around too many concurrent tasks.

[payjoin-bot]

benalleng

@benalleng

Shipped

PRs reviewed:

• Fix unused results in session unit tests
• parallelize FFI language binding tests in contrib/test.sh

Last Week

Review your previous thread: Last week's thread

[benalleng]

Shipped

• pushed more fixed to the liana PR but still think I need to add a bit more polish
• Reviewed some additional PRs but really didn't make as much progress as I hoped with the BB mobile PR but it seems that spacebear figured it out with some pushes yesterday. will try to test.

Focus

• Going to try to focus on review where I can until my son is back at daycare

Bottleneck

• Everyone is home sick so I am really just holding down the fort at the moment

[payjoin-bot]

chavic

@chavic

Shipped

No activity found.

Last Week

Review your previous thread: Last week's thread

[chavic]

Shipped:

Reviewed and merged contributor PRs in the BTCPay Payjoin plugin:

• feat: handle close-requested sessions — merged. (feat: handle close-requested sessions ValeraFinebits/btcpayserver-payjoin-plugin#9)
• fix: add CheatModeRoute to RunTestPayment — merged. (fix: Add CheatModeRoute to RunTestPayment ValeraFinebits/btcpayserver-payjoin-plugin#13)
• test: same-wallet payjoin integration test — merged. (test: Add same-wallet payjoin integration test ValeraFinebits/btcpayserver-payjoin-plugin#14)
• test: enable integration tests for CI — merged. (test: Enable integration tests for CI ValeraFinebits/btcpayserver-payjoin-plugin#15)
• test: unit tests for PayjoinReceiverPoller — merged. (test: Add unit tests for PayjoinReceiverPoller ValeraFinebits/btcpayserver-payjoin-plugin#21)
• feat: improve error handling — under review. (feat: improve error handling ValeraFinebits/btcpayserver-payjoin-plugin#20)
• feat: use external payer for run test payment flow — commented, under review. (feat: use external payer for run test payment flow ValeraFinebits/btcpayserver-payjoin-plugin#16)

PRs:

• Session persistence. (Persist payjoin receiver sessions across restarts ValeraFinebits/btcpayserver-payjoin-plugin#6)
• BTC checkout model and payment toggle merged upstream — checkout model now carries both the Payjoin BIP21 and plain BTC BIP21 URLs, the checkout page lets the payer switch between Payjoin and Standard BTC, Payjoin stays default when enabled in store settings (Add PayJoin checkout model support and payment toggle ValeraFinebits/btcpayserver-payjoin-plugin#22)

Focus:

• PayjoinReceiverPoller initialized OHTTP long-poll timeout logging fix. (PayjoinReceiverPoller logs initialized OHTTP long-poll timeouts as repeated failures ValeraFinebits/btcpayserver-payjoin-plugin#17)
• Demo video showing progress on session persistence and the checkout seam.
• Finally, build a usable build for Cake based on the Dart downgraded branch
• Land plugin artifact freshness tooling so plugin builds stay aligned with FFI sources without manual regeneration. (Add Payjoin artifact freshness tooling chavic/btcpayserver-payjoin-plugin#2)
• Finish up the technical article.

Blockers:

• BTrust technical article deadline will need to be out of the way

[DanGould]

Sounds like there's some ergonomics problem with ErrorState and https://docs.rs/payjoin/latest/payjoin/persist/struct.PersistedError.html#method.error_state the function. Chavic, you say you want the HasReplyableError so that you can propagate it if it exists. This is missing from FFI. What's the workaround? Maybe whatever we return needs an optional conversion that lets you propagate it by replying if it is indeed replyable.

[payjoin-bot]

zealsham

@zealsham

Shipped

Issues opened:

• Payjoin-cli should demonstrate receiver setting expiry

Last Week

Review your previous thread: Last week's thread

Auto-detected signals:

• PR awaiting review: Allow receiver configure session expiry.
• PR has requested changes: OHTTP keys should be rotated
• PR has requested changes: Request size limiter
• PR has requested changes: Demonstrate failure handling with fallback TX broadcast
• PR has requested changes: Add config saving to payjoin-cli

[zealsham]

shipped

• Allow receiver configure session expiry. #1516 waitng for review

Focus

• OHTTP keys should be rotated #1449 new review circle and changes needed
• Track unique shortids seen #1459 new review circle and changes needed

[payjoin-bot]

Mshehu5

@Mshehu5

Shipped

PRs reviewed:

• Avoid deep clone when combining single facts
• Container type + fingerprint summary

Last Week

Review your previous thread: Last week's thread

Auto-detected signals:

• PR awaiting review: [WIP] Add AS-aware relay selection

[Mshehu5]

Focus

Keep working on #1514 also test it to make sure everything works. main goal is to get it into a review ready state to get eyes on it /feedback

Bottleneck

been working on #1514 and did not really get time to work on some issues in tx-indexer willl try and improve efforts there

[payjoin-bot]

0xZaddyy

@0xZaddyy

Shipped

PRs reviewed:

• Avoid deep clone when combining single facts
• Mmap index files

Last Week

Review your previous thread: Last week's thread

Auto-detected signals:

• PR has requested changes: Exclude OP_RETURN outputs from change identification heuristics

[ValeraFinebits]

Shipped

PRs opened:

• feat: improve error handling ValeraFinebits/btcpayserver-payjoin-plugin#20
• test: Add unit tests for PayjoinReceiverPoller ValeraFinebits/btcpayserver-payjoin-plugin#21

PRs reviewed:

• Add PayJoin checkout model support and payment toggle ValeraFinebits/btcpayserver-payjoin-plugin#22

Focus

• Continue working on the plugin.
• Continue reviewing PRs.

[DanGould]

What do you feel is the single biggest bottleneck in progress toward your greater goal?
Name your goal. Name the constraint. Name who or what can unblock it.

I think this is the most important question of the check-in. Also /check-in in a new thread will run the bot on your contributions

[ValeraFinebits]

What do you feel is the single biggest bottleneck in progress toward your greater goal? Name your goal. Name the constraint. Name who or what can unblock it.

I think this is the most important question of the check-in. Also /check-in in a new thread will run the bot on your contributions

My goal is to ship an alpha version and publish it in the plugin directory.
I do not see a clear bottleneck right now, because progress is steady and I'm not currently blocked on anything specific.
The main constraint is simply limited capacity.

[ValeraFinebits]

/check-in

[payjoin-bot]

Shipped

No activity found.

[DanGould]

whoops! my bad with this suggestion. I suppose the plugin isn't tracked yet.

[xstoicunicornx]

Shipped

PRs Opened

• Add Javascript Bindings for Web #1513

Focus

• Finalizing Add Javascript Bindings for Web #1513
• Create PR for alternate version of Non-blocking Interface for Payjoin State Machine  #1446 that uses async callback interface instead

Bottleneck

None (got a bit distracted trying to get a handle on jujustu)

[caarloshenriq]

Shipped

PRs opened:

• (parallelize FFI language binding tests in contrib/test.sh #1504)

PRs reviewed:

• (Add comment-triggered activity collection to payjoin-bot #1503)
• (fix(mailroom): reject post requests over capacity #1509)
• (Fix unused results in session unit tests #1512)

Focus

• Create PR for (Nix flake installs dart 3.9.4, but uniffi-dart requires 3.10 minimum #1501)
• Continue reviewing PRs

[bc1cindy]

Shipped

PRs reviewed:

payjoin/tx-indexer#36
payjoin/tx-indexer#69
payjoin/tx-indexer#73
payjoin/tx-indexer#74
payjoin/tx-indexer#75

Focus

studying and implementing the sparse convolution to privacy metrics
reviewing PRs