Arborist Call | Zcash Protocol Updates (02/05/2026)
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 02/05/2026.
Zebra Updates
Zebra 4.1 highlights:
The Zcash Foundation added new Prometheus metrics and Grafana dashboards, ready for integration with the Z3 stack and built to better surface performance bottlenecks; it also introduced new mempool checks for standard transparent scripts, aligned with zcashd’s behavior.
Shielded coinbase progress:
Work on shielded coinbase transactions is complete and has been tested by mining a mainnet block with a shielded coinbase.
Review is ongoing. Early users can test via the PR implementing ZIP-213.
Former ECC Updates
Backend & SDK refactors:
Low-level refactors in the Zcash client backend aim to reduce duplicated logic across:
SQLite-backed mobile SDKs
Zallet & Zashi
In-memory and custom backend implementations
Result: easier maintenance and more reusable backend logic.
Multisig & chain index updates:
Recent community fund disbursements highlighted friction in current multisig workflows
Work on P2SH multisig is resuming (starting with Keystone firmware)
Remaining blocker for Zallet: missing subtree roots in the chain index API once resolved, deeper integration can proceed.
Zallet & API progress:
Draft “fuzzy get balances” RPC, intended to replace fragmented balance APIs.
New wallet status API proposed to improve test frameworks and sync reliability.
Ongoing PR reviews contributors encouraged to keep them coming.
Zaino Updates
Progress is steady but a few final blockers remain before release.
Key outstanding items include pass-through landing, local cache removal, and serving subtree roots via the chain index.
Transparent address handling clarified.
Zaino correctly supports only P2PKH (t1) and P2SH (t3) addresses the only transparent address formats defined by the Zcash protocol.
Non-standard transparent scripts may exist on-chain, but they aren’t addressable and don’t require special API support beyond raw block/transaction access.
Zcasd Deprecation Updates
Zcashd Deprecation Progress:
Zaino has added support for serving transparent data, advancing feature parity with librustzcash. This will land in an upcoming Zaino release as part of the ongoing transition away from zcashd.
Zaino ←→ Zebra alignment
The Zallet Contributors Board is now actively driving contributions, surfacing well scoped, priority-tagged tasks for external devs.
Community PRs have already landed, with more welcomed, lowering friction for new contributors and accelerating progress.
ZSAs Updates
Work continues on changes stemming from Orchard ZSA review, with most updates now complete. Recent efforts have focused on responding to review feedback and finalizing adjustments in the Orchard crate and related ZIPs.
ZIPs, test vectors & stack alignment
Minor ZIP cleanups are underway (including tightening value-burn bounds). Knock-on updates have been applied across librustzcash, Zebra, and tooling to keep the stack consistent.
ZSA test-vector PRs were split to isolate formatting changes, unblocking review and keeping v6 test vectors aligned with current ZIPs.
What’s next: swaps & infrastructure
Asset-swap work has resumed after the NU7 and Orchard review push, with progress across Orchard, librustzcash, Zebra, and transaction tooling.
QEDIT has also improved its single-node testnet, reducing sync times via smarter caching and state reuse.
NSM Updates
Updates to ZIP-234 clarify the motivation for smoothing issuance and redistributing block rewards burned under ZIP-233. The revised NSM simulator and corrected charts have now been merged.
NSM implementation status
The ZIP-234/235 implementation has been updated in response to reviewer feedback and is pending further review in Zebra.
A remaining blocker is alignment on build / sync flags, which must be standardized across Zebra, Zaino, and librustzcash with discussion underway on formalizing a cross-stack coordination.
Crosslink Updates
Crosslink progress:
Shielded Labs is nearing the end of the prototype phase, following the last 4C workshop.
Core UX and functionality goals for the prototype are now in place, with one final milestone planned to transition Crosslink toward production readiness.
Next steps & analysis
Plans are being discussed for a persistent feature testnet running through 2026 as the foundation for a production Crosslink deployment.
A newly completed mechanism design analysis highlights potential risks and improvements, with further iterations planned.
Work is also ongoing to improve custom testnet workflows in Zebra to better support Crosslink development.
Dynamic Fees Updates
A dedicated R&D call reviewed the draft ZIP design, with substantive feedback from ZIP editors.
Updates addressing that feedback are in progress, with revisions and commits expected shortly.
Open discussion touched on shielded coinbase transactions in Zebra. A draft PR implementing ZIP-213 is already functional and has been used to mine a mainnet block, but remains in draft due to pending dependency PRs.
ZIP-213 status clarified
The PR depends on a small API change in zcash_script, which needs to land, be released, and then pulled into librustzcash before Zebra can merge. Merge conflicts are minor, and the implementation is considered production-ready in practice.
Fun bit + next steps
Shielded coinbase block was born directly in Orchard never touching transparent or legacy code and even included hidden Easter eggs (with the block reward up for grabs.
A lot landed this week from shielded coinbase on mainnet and Zebra 4.1, to steady momentum on Zallet, Zaino, ZSA, NSM, Dynamic Fees, and Crosslink. Solid engineering, open collaboration, real progress.