PDK Dev Call Updates - June 30 2025

[arminsabouri]

PDK Dev Call Updates - June 30 2025

Armin

• Spent the first part of the week wrapping up the sender session persister PR. Replace Persister with SessionPersister for v2 Sender #789
• Continued reviewing Liana integration. Likely one more pass needed to cover all file changes.
• Followed up on exposing fallback transactions in expose fallback tx using receiver session history object #798 Expose fallback tx off receiver session history #799 Sender session history fallback #805.
• Cleaned up #811to separate JSON reply logic from fatal session errors.
• Helped resolve outstanding issues in Add expected_weight field to InputPair #772.
• Owes Dan a write-up for the wallet fingerprinting project.
• Focused on preparing for the release.

Ben

• Paired with Spacebear to get Dart UniFFI compiling. We hit runtime errors but now have workarounds.
• Identified that the session persister wasn’t initializing properly. Dart builds the persister class, but the subclass doesn't extend the abstract base class as expected.
• Started writing unit tests. Next up: integration tests. We’re collecting dependency requirements for those.
• When we hit Dart-side roadblocks, we patch the Dart UniFFI plugin code directly. Spacebear is coordinating with Chavec (maintainer).
• Goal is to push our Dart UniFFI fork upstream eventually.
• For now, working off a fork of the FFI generator.
• Continued work on mutation testing PRs.

Dan

• Release is approaching. It's been three months since the last one. Release payjoin-0.24.0 #825
• Last week went well by staying focused. We prioritized getting SEL in, even if it meant delaying other work.
• We’re assessing the tech debt from that sprint and planning how to clean it up.
• Needs support on error-handling strategy. Tobin (from rust-bitcoin) might help out.
• Finished education material and started drafting a foundation mission statement.
• Main focus: Get a minor release out and identify what else is left till v2 can be stable. We really get that feedback from our integrations.
• Current bottleneck is review bandwidth. Need to build trust with maintainers so more people can review and merge.
• Ran into a TLS cert expiration issue over the weekend. Yuval helped. A backup dir could help avoid this in the future. Yuval's hybrid dir and relay idea could also help https://github.com/orgs/payjoin/discussions/775.

Nothingmuch

• Working on a hybrid directory / OHTTP relay setup.
• Replacing Nginx + Certbot with Caddy for cert management.
• Still coding up the remaining pieces.
• Talked with Armin about making sure issues include clear acceptance criteria.
• Progress blocked a bit by task switching between multiple projects.
• Main focus now:
  • Enable other contributors.
  • Ship the hybrid relay-dir setup.
• This is critical infra for v3. The directory and relay system must resist global passive adversaries.

Spacebear

• PR reviews mostly caught up, should be in good shape for 0.24 release today
• uniffi-dart is now producing compilable dart code!! Ben started writing dart unit tests and identified a runtime error due to missing pointers. I figured out this issue is due to initialization code that doesn't get run automatically when importing the ffi library, so it needs to be initialized manually for now. I'm working on a cleaner fix for uniffi-dart. Should be able to open PRs for dart in rust-payjoin based on my uniffi-dart branch this week, and hopefully start upstreaming the uniffi-dart mods

Shehu

• Merged first contribution: de-duplicated pj_uri construction De-dup pj_uri construction in receiver session history #804
• Has follow-up tasks based on that PR Deduplicate payjoin URI creation logic #812

Zealsham

• Opened a PR to serve a minimal response on / in the directory service Serve a page on / for payjoin-directory #824
• Addressing review feedback from Nothingmuch.
• Blocked on setting up Prometheus metrics due to local dev issues. Running the directory fully in a dev environment is still complex. Introduce simple metrics for payjoin-directory #735

Zele

• Submitted PR for Use IntoUrl for ohttp_relay argument #666, wrapping Bitcoin URI error inside PJ URI error. Refactored code per Dan’s feedback.
• Has 3 years of Dart and Flutter experience, offered to help with UniFFI-Dart. Ben will coordinate.
• Needs review on wrap bitcoin_uri errors in PayjoinUriError type #661.

Weirdrobot

• Opened a PR a few weeks ago adding PartialEq / Eq implementations for errors Implement Eq/PartialEq for error types #645
• Addressed Dan’s feedback, but now the PR has conflicts that need resolving.

[DanGould]

up straight away! Thanks!