Opcodes · introspection · enabled

OP_INPUTINDEX (0xc0)

Pushes the index of the input being evaluated.

Verified
Stack in → out
∅ → i
Since
May 2022: native introspection and 64-bit math
Cost
Base instruction cost 100 plus the byte length of the pushed result (2025 VM limits).
Bitcoin status
Not in Bitcoin (BTC)BTC has no native introspection opcodes. In Tapscript (BIP-342) this byte is an OP_SUCCESSx code reserved for future soft forks.

Example

OP_INPUTINDEX OP_0 OP_NUMEQUAL

Step through it opcode by opcode in Bitauth IDE, the in-browser BCH VM debugger.

Sources

  1. CHIP-2021-02 Native Introspection Opcodes
  2. Libauth BCH_2023_05 opcodes (bch-2023-opcodes.ts)
  3. CHIP-2021-05 VM Limits: Targeted Virtual Machine Limits