OP Code Reference

This reference outlines the integer representations of each virtual machine OP code and the methods available through the public APIs (for both Typescript and Solidity).

OP_DEBUG

Used for debugging. Outputs the machine state to the console. Available only in JavaScript.

Int	JS	Solidity
255	`debug(label: string)`	N/A

OP_TARGET

Pops the top item off the stack and uses it as the target for the following operations.
Resets the slot position to 0.

Int	JS	Solidity
1	`target()`	`target()`

OP_SET_OUTPUT

Pops the top value from the stack and sets it as an output at the specified index.

Int	JS	Solidity
2	`setOutput(i: number)`	`setOutput(uint8 i)`

OP_EVAL_LOOP

Evaluates an expression or operation.

Int	JS	Solidity
3	`evalLoop(opts: {success?: boolean; failure?: boolean; acquire?: boolean; back?: number; } = {})`	`evalLoop(uint8 flags)` / `eval(uint8 flags, uint8 back)`

OP_EVAL_INLINE

Int	JS	Solidity
4	`eval()`	`eval()`

OP_REQ_NONZERO

Ensures the value at a specific offset (back from the top of the stack) is non-zero.
Defaults to the value at the stack's top. If zero, it sets an exit code and returns.

Int	JS	Solidity
10	`requireNonzero(back = 0)`	`requireNonzero(uint8 back)`

OP_REQ_CONTRACT

Checks if the current target is a contract address. If zero, sets an exit code and returns.

Int	JS	Solidity
11	`requireContract()`	`requireContract()`

OP_READ_SLOTS

Reads n slots from the current target starting from the current slot defined in the machine.

Int	JS	Solidity
20	`read(n = 1)`	`read()` / `read(uint8 n)`

OP_READ_BYTES

Reads a bytes value from the storage of the current target.

Int	JS	Solidity
21	`readBytes()`	`readBytes()`

OP_READ_ARRAY

Reads array values from the storage of the current target.

Int	JS	Solidity
22	`readArray(step: number)`	`readArray(uint8 step)`

OP_SLOT_ZERO

Resets the machine slot to 0.

Int	JS	Solidity
30	`zeroSlot()`	`zeroSlot()`

OP_SLOT_ADD

Increments the slot in the virtual machine by the value at the top of the stack.

Int	JS	Solidity
31	`addSlot()`	`addSlot()`

OP_SLOT_FOLLOW

Generates and updates the machine slot ID for a mapping or array using the value at the stack's top as the key/index.

Int	JS	Solidity
32	`follow()`	`follow()`

OP_PUSH_INPUT

Pushes a value from the input register onto the stack. Various helper methods exist for different types.

Int	JS	Solidity
40	`pushInput(i: number)` / `pushStr(s: string)` / `pushBytes(v: BytesLike)` / `push(x: BigNumberish)`	`push(uint256 x)` / `push(address x)` / `push(bytes32 x)` / `push(string memory s)` / `push(bytes memory v)` / `push(GatewayRequest memory x)`

OP_PUSH_OUTPUT

Pushes an output at index i onto the stack.

Int	JS	Solidity
41	`pushOutput(i: number)`	`pushOutput(uint8 i)`

OP_PUSH_SLOT

Pushes the current virtual machine slot onto the stack.

Int	JS	Solidity
42	`pushSlot()`	`readSlot()`

OP_PUSH_TARGET

Pushes the current virtual machine target address onto the stack.

Int	JS	Solidity
43	`pushTarget()`	`readTarget()`

OP_DUP

Pushes the stack item offset from the head by back to the top of the stack.

Int	JS	Solidity
50	`dup(back = 0)`	`dup(uint8 back)`

OP_POP

Removes the top stack item.

Int	JS	Solidity
51	`pop()`	`pop()`

OP_SWAP

Swaps the item at the top of the stack with the item at the specified offset from the head.

Int	JS	Solidity
52	`swap(back = 1)`	``

OP_KECCAK

Computes the Keccak-256 hash of the item at the head of the stack and replaces it on the stack.

Int	JS	Solidity
60	`keccak()`	`keccak()`

OP_CONCAT

Pops and concatenates the last back items on the stack.

Int	JS	Solidity
61	`concat(back: number)`	`concat(uint8 n)`

OP_SLICE

Slices n bytes from the value at the head of the stack starting from offset x.

Int	JS	Solidity
62	`slice(x: number, n: number)`	`slice(uint16 pos, uint16 len)`

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