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 01/22/2026
v4.0.0 is out. 🚀
Key improvements include a new default DNS seeder, better parity with zcashd’s mempool behavior, and expanded config support
TOML files can now use arbitrary extensions.New Rust-based DNS seeder built on Zebra Network (thanks to David Campbell)
Support for custom test networks
Improved error typing in Zebra state
Minor fixes to metrics & diagnostics when connection heartbeat tasks exit.
CLIP
(Former ECC Updates)
Zallet CLI progress:
Work continues on shielded coinbase support
Fully transparent (t→t) functionality is also in progress, closing a feature gap with the legacy zcashd wallet.
Former ECC is proposing a new approach to the v6 transaction format (ZIP PR #1156).
- Goal: make Zcash easier to evolve by minimizing future parser changes and enabling NU7 consensus features to ship in smaller, more manageable releases. Feedback is especially encouraged from wallet developers.
New ZIP is in draft to generalize lockbox functionality into consensus accounts.
This could reduce UTXO management overhead across the ecosystem (grants, miners, issuance), enable key rotation, and potentially remove the coinbase maturity rule.
Regtest issues discussed: inability to spend mined or funded outputs was traced to coinbase maturity handling and missing shielded coinbase support. A librustzcash fix addressing the maturity blocker is ready for review, unblocking downstream wallet work.
CLIP
Zallet Beta is targeting a March release, with a couple more alphas expected beforehand. The team is coordinating with ZF (Gustavo) on the appropriate “z3” containers for the deprecation path, which more users are adopting instead of building from source.
Progress continues via adoption of canonical gRPC service definitions. Missing components are being implemented in Zaino, with the current work under review as the ecosystem transitions away from legacy lightwalletd.
Zallet engineering update: the issue backlog has been reviewed and labeled to surface tasks appropriate for external contributors. Coordination and technical discussion are being tracked via the Zallet GitHub repository, with additional updates expected as this work progresses.
Zaino Updates
Docker setup has been aligned more closely with the z3 system, including fixes to DNS hostname resolution. Additional sync bugs were addressed, with final work focused on cache migration, pass-through testing, and general release hardening.
CLIP
ZIP-233 has been revised to add requirements and privacy implications based on prior audit feedback. Updated PRs for ZIP-234 and ZIP-235 addressing review comments are awaiting review and merge into Zebra, bringing the NSM work close to completion.
A related engineering issue was flagged around NU7 config flag usage in Rust. Since config flags apply across all crates, the teams plan to document a unified approach to prevent incompatible flag handling across the Zcash ecosystem.
CLIP
Milestone 4c workshop is scheduled for the 28th and is expected to include the full intended prototype functionality.
The workshop will feature updated wallets from Zingo (mobile) and Shielded Labs (desktop with visualizer), followed by a broader Q&A on Crosslink.
Looking ahead, the team plans a final prototyping phase (Milestone 5) focused on cleanup and UI refinement, followed by a transition toward productionization. An external mechanism design audit is nearing completion, with early findings indicating no impact on PoW liveness, but a clearly observable risk of finality-layer stalls under malicious mining.
CLIP
Work is resuming with plans to stand up a dedicated testnet for simulations and long-term back/forward testing. Development continues alongside iteration on https://fees.shieldedinfra.net which serves as both a communication surface and an interactive explainer for the proposal.