The NU7 upgrade went live on Zcash's test network on Sunday. Developers will decide on Oct. 20 whether to set a mainnet date, and holders of old Sprout-pool coins have a deadline to move them.
Zcash's biggest protocol change in years is running, for now on the network built for breaking things.
The NU7 network upgrade activated on the Zcash testnet at block 4,465,026 at 18:21:45 UTC on Sunday, Oct. 4, two days ahead of the Oct. 6 date developers had published in September. That timeline, released on Sept. 21, called for code completion by Sept. 30, testnet on Oct. 6 and a mainnet target of Nov. 5. The Zcash Foundation has asked node operators running its Zebra client to test the release "under real conditions."
The real gate comes later. Developers plan to decide on Oct. 20 whether NU7 is ready for mainnet and, if so, at what block height it activates. Until then, Nov. 5 is a target rather than a commitment.
What changes
NU7 cuts Zcash's target block time to 25 seconds from 75 seconds. That triples the number of blocks the network produces, to about 3,456 a day from roughly 1,152, which shortens confirmation times for payments and exchanges.
The upgrade also introduces a Network Sustainability Mechanism that routes part of transaction fees toward future block rewards, a change to how the network funds its security over time. Developers have not yet specified what share of fees the mechanism will capture, which leaves the economic effect open.
The most concrete risk falls on a small group of holders. NU7 disables version 4 transactions, which means coins still sitting in the old Sprout shielded pool become unspendable unless they are moved before activation. Exchanges, custodians and wallet providers holding Sprout balances on behalf of users face an operational deadline that is now visible on the calendar.
A lobbyist for the coin
The upgrade arrives as Zcash's backers build a presence in Washington. Pretty Good Policy for Zcash, a 501(c)(4) advocacy group, has registered its executive director, Divij Pandya, as its first federal lobbyist. The filing lists the CLARITY Act market-structure bill and two digital-asset tax proposals among the issues he will work on.
The market backdrop
ZEC traded at $1,332.12 early Monday, down 1.5%, and about 21% below its Sept. 27 peak near $1,697. It remains well above its 50-day average of $1,095, a reminder of how far the privacy coin has run this year. The Grayscale Zcash Trust (ZCSH), which closed Friday at $34.04, recently recorded its first weekly outflow.
What to watch: Testnet stability through Oct. 20, the decision on a mainnet activation height, and any disclosure of the fee share the sustainability mechanism will take. Exchange notices on Sprout-pool balances would signal how many coins remain exposed to the cutoff.