Arborist Call #104 | R&D Summary (06/26/2025)
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 06/26/2025
Zebra Just Got More Powerful Zebra devs have been on fire!
In the last 2 weeks:
Missing fields added to GetRawTransaction
Value pool data now queryable by block
New mempoolChange gRPC to track real-time updates Zcash infra keeps evolving!
Testers & Devs Two new RPC methods landed in Zebra:
✔️invalidateBlock
✔️reconsiderBlock
Perfect for testing and edge-case debugging.
Plus: deprecated debug configs cleaned up for better UX.invalidateBlock
Zebra RPC Cleanup = Dev UX Win
Zebra’s RPC crate is now cleaner & more usable for client builders.
Naming conventions in CI?✔️
IPv6 enabled by default? ✔️
Client dev with Zebra just got smoother than ever.
Rust Replacing C++ in Zcash?
The zcash_script crate now has a Rust implementation (thanks Greg from ECC) It runs alongside C++ to detect mismatches. Goal: go full Rust.
Zebra is future-proofing
Zallet Alpha Is Coming
ECC urges:
→ Test it now (but only with funds you're OK losing!)
→ Report any bugs, UX friction, or weird behavior This is how we build a better Zcash wallet — together.
Zcash Shielded Assets (ZSA) Momentum
Big strides in Zcash Shielded Assets from @Qedit
Key rotation support w/o TX format change
Major ZSA PR landed in Halo 2
Ongoing reviews by ECC & Zebra teams
Updated Zcash Transaction Tool released
Devs Waiting on Green Checks
Test Vectors PR #101 ,just needs workflows run
Librustzcash PR — waiting on final review Once merged, Zebra gets rebased & progress continues Builders are building
Unblocking Zcash Development
Key Zcash development progress is currently pending final actions:
Test Vectors PR needs workflows triggered
Librustzcash PR awaiting final review
Once cleared, related updates can proceed to Zebra. Timely reviews critical to keeping momentum.
Crosslink Milestone 3 in Motion Zcash Crosslink is progressing:
Milestone 3 introduces consensus link between PoW → ← BFT blocks
Finalizers are hardcoded (PoA-style) for now
Focused on “objective verifiability” by including BFT signatures in-chain
Crosslink PoS design is underway:
Lock ZEC into bonds or delegate to finalizers
Define registration, rewards, slashing, and fee logic
Researching Namada, Cosmos Hub, and Penumbra for design insights Early-stage, but aligned with best-in-class PoS systems.
Formal Verification for Crosslink researchers exploring models for PoS logic using Quint, a specification language from InformalSys
✔️Based on TLA+
✔️Supports temporal logic, non-determinism, state transitions
✔️Aligns with work already being done by other teams like namada
A new milestone: one grantee has successfully integrated a Testnet Block Explorer with Zebra.
Meanwhile, the Zashi team is collecting feedback via a user survey—developers and Zcashers are encouraged to participate to help shape future tools and features.
