Available on private testnetTestnet: yesMainnet: Not availableSoftware: Vyper 0.4.3+commit.bff19ea2Updated 2026-11-08

Vyper

Pinned compiler	0.4.3+commit.bff19ea2 (Windows exe SHA-256 4878e251…7c9a)
EVM target	--evm-version cancun (or london)
Status	✅ Tested: compile, deploy, call on chain 77240 (CLI); Wallet Studio Vyper support is on an unreleased branch

Install

python3 -m venv .venv && . .venv/bin/activate
pip install vyper==0.4.3
vyper --version     # 0.4.3+commit.bff19ea2

The pinned Vyper LICENSE contains terms beyond stock Apache-2.0; read it before redistributing the compiler.

Example

Counter.vy

# pragma version 0.4.3
# Starter counter (Vyper 0.4.3). Unaudited example.

event Incremented:
    value: uint256

CREATOR: public(immutable(address))
count: uint256

@deploy
def __init__():
    CREATOR = msg.sender

@external
def increment():
    self.count += 1
    log Incremented(value=self.count)

@view
@external
def get() -> uint256:
    return self.count

Compile, ABI, deploy

vyper --evm-version cancun -f bytecode Counter.vy > Counter.bin
vyper -f abi Counter.vy > Counter.abi.json          # Vyper generates the ABI
TX=$(cast send --async --keystore "$KEYSTORE" --password-file "$PASSWORD_FILE" --rpc-url "$RPC" --create "$(cat Counter.bin)")
cast receipt "$TX" contractAddress --rpc-url "$RPC"

Measured: 207 runtime bytes, 98,394 deployment gas, 44,431 gas for increment().

Security caveats

• Vyper had compiler bugs in older versions (notably reentrancy-lock miscompilation in 0.2.15–0.3.0); stay on the pinned version and read its advisories.
• @nonreentrant and bounded loops are language features — use them rather than hand-rolled guards.
• Verification works the same way as Solidity (compare runtime bytes; Vyper immutables are appended to runtime code).

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Sources at 72057fe3ec: contracts/studio/compilers.json · developers/examples/languages/Counter.vy

Found a problem? Report a documentation issue · Build testnet-rc1+72057fe3ec