PDK Dev Call Updates – January 20th, 2026

[spacebear21]

Ben

• Flake CI checks got merged. @Mshehu5 also introduced a maintenance check to update flakes regularly on a weekly basis. Action item: move automated PRs to a dedicated payjoin bot.
• Dev shell compiler error #1280
• Mob programming session on fuzzing helped get Introduce fuzzing for payjoin #1153 in better shape. Tracking fuzzing candidates #1267 tracks more useful target candidates that should be introduced in follow-ups.
  • To some extent fuzzing may be useful in testing robust compatibility between integrations, e.g. Cake wallet and Bull Bitcoin Mobile. A priority for 2026 will be setting up standard testing between implementations and a standard test vector set (e.g. against payjoin-cli).
• Remove nix caching on flake checks #1268 needs re-approval (removed caching from maintenance checks also)
• Fuzzing revealed a potential issue with bitcoin_uri roundtrip serialization: unknown parameters get ignored entirely and aren't re-serialized Bitcoin-uri fuzzing crash bitcoin_uri#10
• Meeting Pyth Thursday 09:00 ET re: Liana integrations

chavic

• Dove deeper into FFI Tracking Issue #739 and expanded sub-items with good first issues
  • Preserve OHTTP/HPKE error granularity in FFI bindings #1273 likely highest priority
• Found weird behavior in Validate FFI primitive inputs + refresh bindings/tests #1263 that needs to be fixed before the PR can be undrafted

nothingmuch

• Writing "big ass overview" on multiparty protocol https://github.com/payjoin/multiparty-protocol-docs/blob/overview/00_overview.md
  • do we post a post on email about this once it's merged?
• Developing the tx-indexer platform for defining privacy metrics as standalone crates, and doing analysis on fingerprint, clustering impact on payjoin privacy.
  • Show and tell topic for tomorrow's mob prog session.
• Bringing other researchers up to speed.
  • Multiparty silent payments and Verifiable randomization are hype and ammo for sniping

spacebear

• Async persistence (Async persistence #1236 Implement replay_event_log_async #1266)
  • now working on exposing it to FFI layer
  • follow-up with Bull Bitcoin re: async support
• Unified payjoin service #1232 self-loop detection - ready for review
  • Once merged will port @zealsham 's work from Remove hyper and migrate to axum. #1101 to payjoin-service
• Recruiting channels with Vinteum, BOSS program warming up
• Traveling next week (1/26 - 2/7)

zealsham

• back and forth with Camilarhi on LDK-node payjoin integration PR Add Payjoin Receiver Support lightningdevkit/ldk-node#746
• Looking into FFI

Dan

• Mainly writing grants
• Meeting with PlanB regarding Lugano residency
• Determine focus for upcoming sprints as efforts seem ~widely spread currently
• How to keep dev calls short moving forward? auto-request notes from contributors before hand? hard time limit per individual update?
• Press releases for Cake wallet funding and bitcoin core RPC Alpen collab

[arminsabouri]

• Review all things async persister
• Main focus has and will continue to be the analysis framework. Finishing up the transformation pipeline this week. Same as nothingmuch's update above. Lets do a Q/A / demo tomorrow for mob programming if nothing else is scheduled.
• Collab more on nothingmuch's "big ass overview" towards the end of the week.

@DanGould what does this point mean: "bitcoin core RPC Alpen collab"

[spacebear21]

what does this point mean: "bitcoin core RPC Alpen collab"

My bad for poor note taking: alpen asked for a shoutout about our use of https://github.com/alpenlabs/bitcoind-async-client to promote the project

[DanGould]

w/ regard to async persistence, because our code surface is getting so large across languages I'd rather only support things if they're pulled out of us by people using the bindings. It sounds like that means we do need to cover dart and JS and maybe python works already? But wanted to lay it out as a principle @spacebear21 .

[spacebear21]

I agree in principle, in this case python works already and JS and dart are the ones with actual demand so we're outta luck