# Release: Zakura 1.0.2

Announcement dated 2026-07-20: Zakura 1.0.2, a stability and performance
release. Zakura is a Zcash full node.

What the announcement says:

- Zakura 1.0.2 makes the zcashd compatibility mode substantially more
  reliable and fixes a number of other bugs. All node operators should
  update. Release:
  https://github.com/zakura-core/zakura/releases/tag/v1.0.2
- zcashd compatibility mode (the release's headline improvement; the mode
  runs a real zcashd process with the Zakura node as its only peer,
  described at https://zakura.com/zcashd/): its most visible problem,
  zcashd occasionally stalling behind the chain tip, had three distinct
  causes, and this release fixes all of them. Block announcements to a
  momentarily busy zcashd are no longer dropped (including on locally
  mining nodes); Zakura's denial-of-service protection no longer
  disconnects the operator's own zcashd (its requests are still shed under
  load, and protection for every other peer is unchanged); and supervision
  is more complete (the managed zcashd process is shut down when Zakura
  exits, legacy wallet RPCs are enabled by default with
  `-allowdeprecated=none` as the opt-out, pruned Zakura nodes are
  supported, and requests for block bodies that pruning has dropped get an
  actionable error).
- Other improvements: mempool hardening (the mempool now favors
  protecting miners and RPC operators, with trade-offs chosen to preserve
  every real usage pattern the team has seen: transactions over a
  configurable 250,000-byte default size limit are rejected, many kinds of
  rejection are faster and cheaper, peer penalties follow the root cause
  of what actually went wrong, limiting what a malicious peer can do, and
  an edge case where peers could get banned at the Ironwood (NU6.3)
  upgrade boundary is avoided), faster block template
  refreshes (Sapling proving parameters are parsed once per process and
  the prover shared instead of re-parsing on every getblocktemplate
  refresh, and mempool metrics are maintained incrementally), faster
  transparent signature checks (signature-hash components shared across a
  transaction's inputs are computed once and reused for every transparent
  signature check), pruned nodes no longer advertising block bodies they
  cannot serve to legacy peers, peer addresses redacted in logs and
  metrics by default (new opt-in `network.expose_peer_addresses` setting),
  an early-chain difficulty edge case fixed at the averaging-window
  boundary, and header sync made forward-only from the durable verified
  tip.
- Sprout history repair in experimental fast sync: fresh
  verified-commitment-tree (VCT) fast sync, part of Zakura's experimental
  P2P stack (off by default), did not persist the chain's historical
  Sprout note-commitment history, so an affected node could no longer
  validate a transaction spending against a historical Sprout anchor. Only
  mainnet databases created by fast sync over the experimental transport
  are affected. 1.0.2 fixes the bug and repairs affected databases
  automatically at startup from a reviewed copy of the mainnet Sprout
  history, distributed as exact-versioned crates.io packages and validated
  before any repaired state is written. The repair is crash-safe and
  fail-closed (an interruption restarts it, and an affected database
  refuses to run until its repair completes), and a new read-only command,
  `zakurad validate-vct-sprout-history`, audits the historical Sprout
  anchors of any mainnet database, archive or pruned. Redownloading a
  snapshot (https://zakura.com/snapshots/) or resyncing from genesis are
  the alternatives to repairing in place.
- End of support: Zakura 1.0.2 supports Ironwood (NU6.3) activation and
  reaches end of support roughly ten days after it, by which point the
  first post-Ironwood release will be available. Nodes still on 1.0.1
  reach end of support roughly one week after activation: they begin
  warning about the required update a few days beforehand and then halt.
  Operators should update now rather than during the activation window.
- Updating: signed release binaries
  (https://github.com/zakura-core/zakura/releases/tag/v1.0.2) or upgrading
  the `zakura` crate to 1.0.2 via Cargo; installation and verification
  instructions are on the download page (https://zakura.com/download/).

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Canonical HTML version: https://zakura.com/announcements/zakura-1-0-2/