Tapscript

Tapscript is the scripting language used for taproot script-path spends.

It shares most operations with legacy and segwit Bitcoin Script but has a few differences:

• OP_CHECKMULTISIG and OP_CHECKMULTISIGVERIFY are replaced by a OP_CHECKSIGADD opcode.

• Many previously disabled opcodes are redefined to be OP_SUCCESS opcodes that unconditionally render the entire script valid to simplify soft fork upgrades.

• Signature hashes are calculated differently than in legacy script or BIP143 v0 segwit.

Primary code and documentation

• bip-tapscript

Optech newsletter and website mentions

2023

• Research showing effect of OP_SUCCESSx on covenants using output script introspection
• Description of tapscript signature malleability and proposed fix for SIGHASH_ANYPREVOUT

2022

• Discussion about lowering tapscript resource limits
• Question: why do invalid OP_CHECKSIGADD signatures fail their script?

2021

• Rust Bitcoin #644 adds support for tapscript’s new opcodes
• Bitcoin Core #21365 allows the wallet to create signatures for tapscript spends
• Using backup tapscript spending paths to recover from crypto breaks

2020

• 2020 year in review: Taproot, tapscript, and schnorr signatures
• Bitcoin Core #19953 merged with consensus implementation of BIP342
• Bitcoin Core #16902 fixes an inefficiency in OP_IF related opcodes
• btcdeb adds tap command for experimenting with taproot and tapscript

2019

• 2019 year-in-review: taproot and tapscript
• Discussion about position commitments using signature-checking opcodes
• Bitcoin Optech schnorr/taproot workshop
• Announcement of structured taproot review (including tapscript)
• Update on changes to schnorr, taproot, and tapscript
• Tapscript resource limits
• BIP322 signmessage forward compatibility
• Executive briefing: Taproot and Tapscript
• Overview of Taproot and Tapscript
• Extended summary of bip-taproot and bip-tapscript

See also

• Taproot

  
  

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