Arborist Call #109 (09/04/2025) | Zcash Protocol Updates
Core Team Updates, Research & Implementation Updates, Open Announcements & Discussion.
The Zcash Arborist Calls are bi-weekly protocol development meetings focused on tracking upcoming protocol deployment logistics, consensus node implementation issues, and protocol research.
This summary focuses on the last call that took place on 09/04/2025
Conrado shared progress on Zebra:
Added Orchard + Sprout fields to getrawtransaction RPC.
Completed missing field in z_gettreestate RPC.
Migrated Zebra to layered config (TOML) → easier deploys & CI.
Zebra now uses librustzcash for Sapling verification → leaner codebase Refactoring CI & cleaning up RPC gaps.
Long term: replace custom Zebra tx types w/ librustzcash types.
Next: more support for Zallet & Zaino as Zcashd Deprecation nears.
Daira: Drafted ZIP-48 (P2SH multisig, needed for NU6.1), preparing for Zallet alpha, investigating bugs in Zashi & librustzcash.
Kris: Zallet alpha will use z_viewtransaction + z_listunspent to retire confusing Zcashd RPCs.
Str4d: Anchor height vs. confirmation fix rolling out via mobile SDKs (thanks to Mitschel, new ECC eng). Faster spends coming for Zashi, Edge & others.
Kris/Pacu: sendMax merged, Chainsafe’s in-memory wallet integrated.
Daira: Protocol spec changes for NU6.1 nearly done.
Za (Zingo Labs):
✅ Grant proposal pushed
✅ Addressing Zallet dev feature requests ahead of alpha
✅ Zaino redesign to strengthen type safety
✅ Upgrading for NU6.1 support (expected this week)
Pacu: Network Upgrade outreach survey underway → exchanges providing feedback to smooth future upgrades.
Also praised Alfredo’s new testing framework for Zebra RPCs, accelerating dev workflows.
Bug triaging + integration work ongoing.
On Zcashd Deprecation:
Str4d & Daira: Expect more features deprecated (but enabled by default) as focus shifts to Zallet migration.
RPC docs improving via OpenRPC; discussions on standardization.
Pacu: Goal isn’t 1:1 port of zcashd , avoid carrying tech debt, build cleaner stack.
Pablo (QEDIT): Orchard ZSA is now spec complete
Recent updates: SIG hash versioning + issuance key changes
Python reference implementation & Orchard ZSA circuit ready for independent review
Backward compatibility maintained w/ Orchard v5 bundles
Transaction v6 → designed to be future-proof for NU
Supports Orchard ZSA, NSM, and fee changes
Both Python ref implementation + librustzcash draft PR available
Goal: spec-complete implementation of ZIP-230
Daira & Str4d: Python code for transaction v6 is simple & clear—ideal for generating test vectors
Helps devs verify full transaction parsing
Prevents past issues
Ensures protocol compliance across implementations
Pablo: Zebra node now tracks global state for ZSA
Supply of issued assets
Finalization rules for assets
New consensus checks integrated
Also proposed a new health RPC endpoint for easier node monitoring.
(MARK)Shielded Labs:
NSM (ZIP-233) test vectors updated ✅ PRs merged & CI fixes landed. Next step: tackle the main Zebra PR.
Next step: tackle the main Zebra PR.
ZIP 234 & ZIP 235 remain unchanged. Work continues on the NSM simulator repo (fork available for contributions).
Nate: Milestone 3 workshop demoed rollback prevention past finality despite hiccups, progress made.
Next: Milestone 4 → add proof-of-stake, starting with 4.1 (simpler testnet + easy join instructions).
Blog post on staking implications coming soon
Daira asked about Crosslink’s approach to economic mechanism design.
Nate: Focus for 2025 is simple prototype → minimal rules, avoid complexity like slashing/fees initially. Privacy-motivated wrinkle: unbonding period may be added later.
Str4d: A test run of Zallet was delayed due to blocking bugs, but should happen soon.
Interested in trying the pre-alpha/alpha? Join the Zcash R&D Discord to participate in upcoming hands-on testing.
Pablo, Daira, Str4d discussed the post-quantum resilience ZIP:
Draft work is underway after NU6.1.
Could ride alongside NU7 (with ZSAs & memo bundles).
Debate: how to ensure wallet compatibility + avoid past pifalls. Do you think PQ resilience should be prioritized for NU7?