Deploy a Contract

Deploy and verify smart contracts on Taiko using Foundry.

Prompt mode

Paste this into your coding agent:

Reference https://docs.taiko.xyz/SKILL.md
 
Write a minimal Counter contract at src/Counter.sol, then deploy and verify
it on Taiko mainnet. Use FOUNDRY_PROFILE=taiko to target Shanghai EVM and
verify via the Etherscan V2 endpoint:
https://api.etherscan.io/v2/api?chainid=167000

Manual mode

Prerequisites

Foundry installed
ETH on Taiko (bridge from L1 or use a Hoodi faucet — see Bridge Tokens)
An Etherscan API key — the V2 unified key verifies on Taikoscan too

Scaffold a project

forge init hello-taiko && cd hello-taiko

forge init generates src/Counter.sol — a minimal contract we'll deploy below. If an agent is driving the flow, have it write a contract into src/ and use that filename instead.

Configure Foundry

Add a Taiko profile to foundry.toml:

[profile.taiko]
evm_version = "shanghai"

Build with it:

FOUNDRY_PROFILE=taiko forge build

Deploy and verify

Mainnet

FOUNDRY_PROFILE=taiko forge create src/Counter.sol:Counter \
  --rpc-url https://rpc.mainnet.taiko.xyz \
  --private-key $PRIVATE_KEY \
  --broadcast \
  --verify \
  --verifier etherscan \
  --verifier-url 'https://api.etherscan.io/v2/api?chainid=167000' \
  --etherscan-api-key $ETHERSCAN_API_KEY

--broadcast is required — without it, forge create only simulates.

Confirm deployment

cast code $DEPLOYED_ADDRESS --rpc-url https://rpc.mainnet.taiko.xyz

A non-empty hex response confirms the contract exists on-chain.

Verify an already-deployed contract

Same V2 URL, with forge verify-contract:

FOUNDRY_PROFILE=taiko forge verify-contract $CONTRACT_ADDRESS \
  src/Counter.sol:Counter \
  --verifier etherscan \
  --verifier-url 'https://api.etherscan.io/v2/api?chainid=167000' \
  --etherscan-api-key $ETHERSCAN_API_KEY \
  --watch

Swap chainid=167000 → chainid=167013 for Hoodi. --watch blocks until Taikoscan returns a final status.

If your constructor takes arguments, pass them with --constructor-args using the same values you deployed with. Encode complex types first: cast abi-encode "constructor(address,uint256)" 0xYourAddress 1000000000000000000.

Troubleshooting

Problem	Cause	Fix
`forge create` prints ABI but nothing deploys	Missing `--broadcast`	Add `--broadcast` to the command
Deployment reverts with no error	Wrong EVM version	Set `evm_version = "shanghai"` in `foundry.toml` and rebuild
`EvmError: NotActivated`	Cancun opcode on Shanghai	Same as above — rebuild with `FOUNDRY_PROFILE=taiko`
`insufficient funds`	Not enough ETH on Taiko	Bridge ETH from L1 or use the Hoodi faucet
`deprecated V1 endpoint`	Using `api.taikoscan.io/api`	Switch to `https://api.etherscan.io/v2/api?chainid=167000`
`NOTOK: Unable to verify`	EVM version mismatch	Recompile with `evm_version = "shanghai"` and redeploy
`NOTOK: Already Verified`	Contract is already verified	No action needed — check the explorer
Bytecode mismatch	Compiler version differs	Use the exact `solc` version from your build (check with `forge config`)
Missing constructor args	Args not provided or mis-encoded	Pass `--constructor-args` with the same values used at deploy time
`Invalid API Key`	Key not set or wrong key	Get an Etherscan API key — the V2 key works for all chains