Opcodes · function · enabled

OP_INVOKE (0x8a)

Pops a function identifier and runs that function's bytecode on the current stack, then continues after OP_INVOKE. Fails if no function has that identifier. This byte was OP_RESERVED2 before May 2026.

Verified
Stack in → out
… id → …
Since
May 2026 (Layla): loops, functions, bitwise ops and Pay-to-Script
Cost
Base instruction cost 100, plus the cost of every instruction the function runs. Each call uses a control-stack frame (depth limit 100).
Bitcoin status
Not in Bitcoin (BTC)0x8a is OP_RESERVED2 in BTC; an OP_SUCCESS code in Tapscript.

Example

<OP_DUP OP_MUL> OP_0 OP_DEFINE OP_3 OP_0 OP_INVOKE OP_9 OP_EQUAL

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

Sources

  1. CHIP-2025-05 Functions: Function Definition and Invocation Operations
  2. Libauth BCH_2026_05 opcodes (bch-2026-opcodes.ts)
  3. Announcing Bitcoin Cash Node v29.0.0