Zecnero

Wallet 0.3.0-beta and the upgrade at block 16,529

By Zecnero ·

The testnet upgrades at block 16,529, expected around October 8, 2026 at 22:00 UTC. What nodes, miners and wallets need, and wallet 0.3.0-beta, an Orchard beta. Wallet 0.2.2 stays the recommended wallet.

The Zecnero testnet upgrades at block 16,529, expected around Thursday, October 8, 2026 at 22:00 UTC. The upgrade is called NU1. This post sums up what changes at that block and what to run before it, and introduces wallet 0.3.0-beta, a beta that adds Orchard. Wallet 0.2.2 stays the recommended wallet. Testnet coins have no value.

What changes at block 16,529

  • Payments are shielded. Only coinbase transactions may have transparent outputs: the miner’s reward and the founder output. Every other transaction pays Sapling or Orchard outputs, change included, and the network refuses a payment to an nm… address. Transparent coins can still be spent, into a shielded address.
  • Mined coins are shielded before they are spent. The testnet’s exception to this rule ends, so the testnet follows the Mainnet rule. Coinbase still matures after 100 blocks.
  • Difficulty reacts faster. The ASERT half-life goes from 2 hours to 1 hour. The formula is re-anchored at the block before the upgrade, so difficulty carries on with no jump.
  • A new branch ID. From block 16,529 transactions carry the branch ID 0x02524D5A. Transactions built for the old rules are not valid from that block, and nodes drop them from their mempools.
  • Orchard. The node’s Orchard rules do not change: it verifies Orchard under the corrected circuit before and after the upgrade. The fix for Orchard proofs built by wallets switches on with the upgrade, and wallet 0.3.0-beta uses Orchard from that block.

Mainnet applies the NU1 rules from its first block. The upgrade announcement explains the reasons.

When, and how to check the height

The rules switch at the height, not at a time. At 75 seconds a block, block 16,529 is expected around October 8 at 22:00 UTC, but the pace follows the hashrate, so it can come earlier or later.

  • The explorer shows the current height.
  • Solo miners: zecnero-miner status shows your node’s height on the Node: line. It should match the explorer.
  • Your own node: getblockchaininfo lists the upgrade under upgrades as 02524d5a, with activationheight 16529 and status pending until the block arrives. If it shows another height, or no such entry, upgrade the node.

Node operators: zecnerod 0.2.0

Run zecnerod 0.2.0, from the testnet-v0.2.0 release of October 4 on the file host. zecnerod --version prints zecnerod 0.2.0. With the one-command install, zecnero-miner update installs it.

A node that has not upgraded stops at block 16,528 and loses its peers, and blocks mined on it after that never count. Upgrade the node and start it again, and it carries on with the chain.

Miners

  • No new miner for NU1. The upgrade does not change the proof of work, the block header or the RandomX key. Any released xmrig-zecnero keeps working through it. The next miner update is for NU2, the upgrade that changes the proof of work; it gets its own post.
  • On the pool, log in with a Sapling address. From block 16,529 the pool refuses nm… logins and closes sessions that still use one. Use your ntestsapling1… address as the login, with .worker after it if you like. The pool does not take a unified address as a login, so use the Sapling one even with wallet 0.3.0-beta. With the one-command install, zecnero-miner pool-login new makes a wallet and uses its Sapling address, and zecnero-miner pool-login ntestsapling1… sets one you already have. With your own xmrig-zecnero, set -u to the Sapling address.
  • Pool balances on an nm… login: at block 16,469, about 75 minutes before the upgrade, the pool pays out every nm… balance. The upgrade announcement says how to register a Sapling address for anything credited after that.
  • Solo with your own node: update the node to 0.2.0. Rewards still go to your nm… address. Shield them with the wallet before you spend them.

Wallets

Use wallet 0.2.2, from the wallets page. It follows the chain through the upgrade. Wallet 0.2.1 stops syncing at block 16,529.

Wallet 0.3.0-beta: Orchard

Wallet 0.3.0-beta is a beta for people who want to try Orchard on the testnet. It is a command-line wallet for Linux and Windows and a desktop wallet for Windows, like 0.2.2.

  • Orchard. Orchard keys come from the same 24-word seed. The wallet finds Orchard notes in the same scan as Sapling notes, spends them, and counts them in the balance.
  • Unified addresses. zecnero-wallet unified-address (or ua, with --new for a fresh one) prints a unified address, nutest1…, with Orchard, Sapling and transparent receivers. The desktop wallet shows it as the default receive address. Sends accept unified addresses. Zcash addresses (u1…) and unified addresses of another Zecnero network are refused.
  • Shield to Orchard. zecnero-wallet shield --pool orchard moves mined coins to your Orchard address.

Orchard starts at block 16,529. Before that block the beta builds no Orchard part in any transaction: a shield asked for Orchard goes to your Sapling address, and the preview says so; a unified address is paid through its Sapling receiver; a unified address with only an Orchard receiver is refused. From block 16,529 Orchard works with no action on your part.

Your wallet file: format 2, which 0.2.2 cannot open

The beta stores the wallet in file format 2. Wallet 0.2.2 and older cannot open it; they stop with “unsupported wallet file version 2”. The first time the beta opens a wallet written by 0.2.x, it:

  1. copies the file unchanged to the same name plus .v1.bak, in the same folder (testnet.wallet becomes testnet.wallet.v1.bak), unless a file with that name already exists, in which case it keeps that one;
  2. rewrites the wallet file in format 2, at once;
  3. scans the shielded pools again from the wallet’s birthday, which takes a while. Keys, addresses, labels, imported keys, pending sends and transparent coins are kept.

The wallet file is ~/.local/share/zecnero-wallet/testnet.wallet on Linux and %APPDATA%\zecnero-wallet\testnet.wallet on Windows. The command-line wallet and the desktop wallet use the same file.

To keep a copy that 0.2.2 can open, close every wallet program, then copy testnet.wallet to another folder before you start the beta. Or try the command-line beta on a copy and leave your wallet as it is:

cp ~/.local/share/zecnero-wallet/testnet.wallet ~/.local/share/zecnero-wallet/beta.wallet
./zecnero-wallet-linux-x86_64 --wallet ~/.local/share/zecnero-wallet/beta.wallet balance

The desktop wallet always opens testnet.wallet, so for it, copy the file first.

To go back to 0.2.2, close the beta, copy testnet.wallet.v1.bak (or your own copy) over testnet.wallet, and start 0.2.2. It then scans the blocks since that copy was made. Wallet 0.2.2 does not see Orchard notes at all: coins sent to your Orchard address stay on the chain, and the beta shows them again. Your 24-word seed restores the wallet in either version.

Download and check

The files are in the wallet-v0.3.0-beta folder of the file host, with a signed checksum list:

Check the signature first, then the files, in the folder you downloaded them to:

curl -O https://zecnero.org/zecnero.asc
gpg --import zecnero.asc
gpg --fingerprint 653209A344E75767
gpg --verify SHA256SUMS.asc SHA256SUMS
sha256sum -c --ignore-missing SHA256SUMS

The fingerprint must read FFFC 8AC0 2BF7 B4B4 50B4 3B1F 6532 09A3 44E7 5767, the same release key as the node. On Linux, run chmod +x zecnero-wallet-linux-x86_64 once it has verified. Keep all the files from the desktop wallet’s zip together in one folder when you unzip it. The desktop wallet has no code signature, so Windows SmartScreen warns the first time you start it. The wallets page lists the beta below 0.2.2 and has the check on Windows.

Each program was built twice in fresh containers, and both builds were byte-identical.

Problems and questions

Questions go to Discord, and bugs to GitLab. For a wallet bug, say whether you use 0.2.2 or 0.3.0-beta, the command-line or the desktop wallet, and what it printed. Never post your seed words or passphrase. Testnet coins have no value. Mainnet has not launched and is planned for Q4 2026.

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