Taproot’s activation height was 709,632. The Bitcoin Core 0.21.1 release notes specify that height, conditional on the signaling process locking in. The activation block’s header records November 14, 2021, in UTC.
Two ways to spend
BIP 341 defines a Taproot output that can be spent through a key path or a script path. The key path uses a Schnorr signature. The script path reveals a chosen script and the information needed to prove its commitment, without revealing every unused alternative. Read BIP 341.
The upgrade spans multiple proposals: BIP 340 specifies Schnorr signatures, BIP 341 defines Taproot, and BIP 342 specifies Tapscript. The release notes identify all three. Upgrade scope.
A narrower privacy claim
Unused spending conditions can remain undisclosed. That is a specific privacy property, not a claim that addresses, amounts, or payment flows vanish from the ledger. The benefit depends on how funds are received and spent. Taproot’s design.
Activation is not universal adoption
A rule becoming available at an activation height is different from every wallet immediately using it. The historical milestone is the new validation capability; a claim about adoption requires separate, dated evidence.
For the underlying idea of spending conditions, start with keys and wallets.