> ## Documentation Index > Fetch the complete documentation index at: https://docs.celo.org/llms.txt > Use this file to discover all available pages before exploring further. # Transaction Types on Celo export const InlineImage = ({src, alt = '', height = '1.6em'}) => { return {alt}; }; This page contains an explainer on transaction types supported on Celo and a demo to make specific transactions. *** ## Summary Celo has support for all Ethereum transaction types (i.e. "100% Ethereum compatibility") and a single Celo transaction type. ### Actively Supported on Celo | Chain | Transaction type | # | Specification | Recommended | Support | Comment | | -------------------------------------------------------------------- | -------------------------- | ----- | ------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------ | --------- | -------------------------------------------------------- | | | Dynamic fee transaction v2 | `123` | [CIP-64](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0064.md) | ✅ | Active 🟢 | Supports paying gas in custom fee currencies | | | Set code transaction | `4` | [EIP-7702](https://eips.ethereum.org/EIPS/eip-7702) | Available since the Isthmus hardfork | | | | | Dynamic fee transaction | `2` | [EIP-1559](https://eips.ethereum.org/EIPS/eip-1559) ([CIP-42](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0042.md)) | ✅ | Active 🟢 | Typical Ethereum transaction | | | Access list transaction | `1` | [EIP-2930](https://eips.ethereum.org/EIPS/eip-2930) ([CIP-35](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0035.md)) | ❌ | Active 🟢 | Does not support dynamically changing *base fee* per gas | | | Legacy transaction | `0` | [Ethereum Yellow Paper](https://ethereum.github.io/yellowpaper/paper.pdf) ([CIP-35](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0035.md)) | ❌ | Active 🟢 | Does not support dynamically changing *base fee* per gas | ### Deprecated on Celo | Chain | Transaction type | # | Specification | 　 Support | Comment | | ---------------------------------------------------------------- | ----------------------- | ----- | -------------------------------------------------------------------------------------------------------------- | ------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | Dynamic fee transaction | `124` | [CIP-42](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0042.md) | Deprecated 🔴 | Deprecation warning published in [Gingerbread hard fork](https://github.com/celo-org/celo-proposals/blob/8260b49b2ec9a87ded6727fec7d9104586eb0752/CIPs/cip-0062.md#deprecation-warning) and no longer supported following the transition to Celo L2 | | | Legacy transaction | `0` | Celo Mainnet launch ([Blockchain client v1.0.0](https://github.com/celo-org/celo-blockchain/tree/celo-v1.0.0)) | Deprecated 🔴 | Deprecation warning published in [Gingerbread hard fork](https://github.com/celo-org/celo-proposals/blob/8260b49b2ec9a87ded6727fec7d9104586eb0752/CIPs/cip-0062.md#deprecation-warning) and no longer supported following the transition to Celo L2 | The stages of support are: * **Active support** 🟢: the transaction type is supported and recommended for use. * **Security support** 🟠: the transaction type is supported but not recommended for use because it might be deprecated in the future. * **Deprecated** 🔴: the transaction type is not supported and not recommended for use. ### Client Library Support Legend: * = support for the recommended Ethereum transaction type (`2`) * = support for the recommended Celo transaction type (`123`) * ✅ = available * ❌ = not available | Client library | Language | | | since | Comment | | --------------------- | :------: | :------------------------------------------------------------------: | :--------------------------------------------------------------- | --------------------------------------------------------------------------- | ------------------------------------------------ | | `viem` | TS/JS | ✅ | ✅ | >[1.19.5][1] | --- | | `ethers` | TS/JS | ✅ | ❌ | | Support via fork in
`celo-ethers-wrapper` | | `celo-ethers-wrapper` | TS/JS | ✅ | ✅ | >[2.0.0](https://github.com/jmrossy/celo-ethers-wrapper/releases/tag/2.0.0) | --- | | `web3js` | TS/JS | ✅ | ❌ | | Support via fork in
`contractkit` | | `contractkit` | TS/JS | ✅ | ✅ | >[5.0.0](https://github.com/celo-org/celo-monorepo/releases/tag/v5.0) | --- | | `Web3j` | Java | ✅ | ❌ | | --- | | `rust-ethers` | Rust | ✅ | ❌ | | --- | | `brownie` | Python | ✅ | ❌ | | --- | [1]: https://github.com/wevm/viem/blob/main/src/CHANGELOG.md#1195 ## Background ### Legacy Transactions Ethereum originally had one format for transactions (now called "legacy transactions"). A legacy transaction contains the following transaction parameters: `nonce`, `gasPrice`, `gasLimit`, `recipient`, `amount`, `data`, and `chaindId`. To produce a valid "legacy transaction": 1. the **transaction parameters** are [RLP-encoded](https://eth.wiki/fundamentals/rlp): ``` RLP([nonce, gasprice, gaslimit, recipient, amount, data, chaindId, 0, 0]) ``` 2. the RLP-encoded transaction is hashed (using Keccak256). 3. the hash is signed with a private key using the ECDSA algorithm, which generates the `v`, `r`, and `s` **signature parameters**. 4. the transaction *and* signature parameters above are RLP-encoded to produce a valid **signed transaction**: ``` RLP([nonce, gasprice, gaslimit, recipient, amount, data, v, r, s]) ``` A valid signed transaction can then be submitted on-chain, and its raw parameters can be parsed by RLP-decoding the transaction. ### Typed Transactions Over time, the Ethereum community has sought to add new types of transactions such as dynamic fee transactions ([EIP-1559: Fee market change for ETH 1.0 chain](https://eips.ethereum.org/EIPS/eip-1559)) or optional access list transactions ([EIP-2930: Optional access lists](https://eips.ethereum.org/EIPS/eip-2930)) to supported new desired behaviors on the network. To allow new transactions to be supported without breaking support with the legacy transaction format, the concept of **typed transactions** was proposed in [EIP-2718: Typed Transaction Envelope](https://eips.ethereum.org/EIPS/eip-2718), which introduces a new high-level transaction format that is used to implement all future transaction types. ### Distinguishing Between Legacy and Typed Transactions Whereas a valid "legacy transaction" is simply an RLP-encoded list of **transaction parameters**, a valid "typed transactions" is an arbitrary byte array prepended with a **transaction type**, where: * a **transaction type**, is a number between 0 (`0x00`) and 127 (`0x7f`) representing the type of the transaction, and * a **transaction payload**, is arbitrary byte data that encodes raw transaction parameters in compliance with the specified transaction type. To distinguish between legacy transactions and typed transactions at the client level, the EIP designers observed that the **first byte** of a legacy transaction would never be in the range `[0, 0x7f]` (or `[0, 127]`), and instead always be in the range `[0xc0, 0xfe]` (or `[192, 254]`). With that observation, transactions can be decoded with the following heuristic: * read the first byte of a transaction * if it's bigger than `0x7f` (`127`), then it's a **legacy transaction**. To decode it, you must read *all* bytes (including the first byte just read) and interpret them as a legacy transaction. * else, if it's smaller or equal to `0x7f` (`127`), then it's a **typed transaction**. To decode it you must read the *remaining* bytes (excluding the first byte just read) and interpret them according to the specified transaction type. Every transaction type is defined in an EIP, which specifies how to *encode* as well as *decode* transaction payloads. This means that a typed transaction can only be interpreted with knowledge of its transaction type and a relevant decoder. ## List of Transaction Types on Celo ### Legacy Transaction (`0`) This transaction type is 100% compatible with Ethereum and has no Celo-specific parameters. Although legacy transactions are never formally prepended with the `0x00` transaction type, they are commonly referred to as "type 0" transactions. * This transaction is defined as follows: ``` RLP([nonce, gasprice, gaslimit, recipient, amount, data, v, r, s]) ``` * It was introduced on Ethereum during Mainnet launch on [Jul 30, 2015](https://en.wikipedia.org/wiki/Ethereum) as specified in the [Ethereum Yellow Paper](https://ethereum.github.io/yellowpaper/paper.pdf). * It was introduced on Celo during the [Celo Donut hard fork](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0027.md) on [May 19, 2021](https://blog.celo.org/donut-hardfork-is-live-on-celo-585e2e294dcb) as specified in [CIP-35: Support for Ethereum-compatible transactions](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0035.md). ### Access List Transaction (`1`) This transaction type is 100% compatible with Ethereum and has no Celo-specific parameters. * This transaction is defined as follows: ``` 0x01 || RLP([chainId, nonce, gasPrice, gasLimit, to, value, data, accessList, signatureYParity, signatureR, signatureS]) ``` * It was introduced on Ethereum during the Ethereum Berlin hard fork on [Apr, 15 2021](https://ethereum.org/en/history/#berlin) as specified in [EIP-2930: Optional access lists](https://eips.ethereum.org/EIPS/eip-2930). * It was introduced on Celo during the [Celo Donut hard fork](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0027.md) on [May 19, 2021](https://blog.celo.org/donut-hardfork-is-live-on-celo-585e2e294dcb) as specified in [CIP-35: Support for Ethereum-compatible transactions](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0035.md). ### Dynamic Fee Transaction (`2`) This transaction type is 100% compatible with Ethereum and has no Celo-specific parameters. * This transaction is defined as follows: ``` 0x02 || RLP([chainId, nonce, maxPriorityFeePerGas, maxFeePerGas, gasLimit, to, value, data, accessList, signatureYParity, signatureR, signatureS]) ``` * It was introduced on Ethereum during the Ethereum London hard fork on [Aug, 5 2021](https://ethereum.org/en/history/#london) as specified in [EIP-1559: Fee market change for ETH 1.0 chain](https://eips.ethereum.org/EIPS/eip-1559). * It was introduced on Celo during the [Celo Espresso hard fork](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0041.md) on [Mar 8, 2022](https://blog.celo.org/brewing-the-espresso-hardfork-92a696af1a17) as specified in [CIP-42: Modification to EIP-1559](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0042.md) ### Set Code Transaction (`4`) This transaction type is 100% compatible with Ethereum and has no Celo-specific parameters. * This transaction is defined as follows: ``` 0x04 || RLP([chainId, nonce, maxPriorityFeePerGas, maxFeePerGas, gasLimit, to, value, data, accessList, authorizationList, signatureYParity, signatureR, signatureS]) ``` * It was introduced on Ethereum during the Ethereum Pectra hard fork on [May, 7 2025](https://ethereum.org/en/history/#pectra) as specified in [EIP-7702: Set Code for EOAs](https://eips.ethereum.org/EIPS/eip-7702). * It is scheduled for support on Celo during the [Celo Isthmus](/infra-partners/notices/archive/isthmus-upgrade) hardfork. ### Legacy Transaction (`0`) This transaction type is no longer supported following the migration to Celo L2. This transaction is not compatible with Ethereum and has three Celo-specific parameters: `feecurrency`, `gatewayfeerecipient`, and `gatewayfee`. * This transaction is defined as follows: ``` RLP([nonce, gasprice, gaslimit, feecurrency, gatewayfeerecipient, gatewayfee, recipient, amount, data, v, r, s]) ``` * It was introduced on Celo during Mainnet launch on [Apr 22, 2020](https://dune.com/queries/3106924/5185945) as specified in [Blockchain client v1.0.0](https://github.com/celo-org/celo-blockchain/tree/celo-v1.0.0). ### Dynamic Fee Transaction (`124`) This transaction type is no longer supported following the migration to Celo L2. This transaction is not compatible with Ethereum and has three Celo-specific parameters: `feecurrency`, `gatewayfeerecipient`, and `gatewayfee`. > **Warning** > This transaction type is scheduled for deprecation. A deprecation warning was published in the > [Gingerbread hard fork](https://github.com/celo-org/celo-proposals/blob/8260b49b2ec9a87ded6727fec7d9104586eb0752/CIPs/cip-0062.md#deprecation-warning) > on [Sep 26, 2023](https://forum.celo.org/t/mainnet-alfajores-gingerbread-hard-fork-release-sep-26-17-00-utc/6499). * This transaction is defined as follows: ``` 0x7c || RLP([chain_id, nonce, max_priority_fee_per_gas, max_fee_per_gas, gas_limit, feecurrency, gatewayfeerecipient, gatewayfee, destination, amount, data, access_list, v, r, s]) ``` * It was introduced on Celo during the [Celo Espresso hard fork](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0041.md) on [Mar 8, 2022](https://blog.celo.org/brewing-the-espresso-hardfork-92a696af1a17) as specified in [CIP-42: Modification to EIP-1559](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0042.md). ### Dynamic Fee Transaction v2 (`123`) This transaction is not compatible with Ethereum and has one Celo-specific parameter: `feecurrency`. * This transaction is defined as follows: ``` 0x7b || RLP([chainId, nonce, maxPriorityFeePerGas, maxFeePerGas, gasLimit, to, value, data, accessList, feeCurrency, v, r, s]) ``` * It was introduced on Celo during the [Celo Gingerbread hard fork](https://github.com/celo-org/celo-proposals/blob/8260b49b2ec9a87ded6727fec7d9104586eb0752/CIPs/cip-0062.md) on [Sep 26, 2023](https://forum.celo.org/t/mainnet-alfajores-gingerbread-hard-fork-release-sep-26-17-00-utc/6499) as specified in [CIP-64: New Transaction Type: Celo Dynamic Fee v2](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0064.md) ## How to Send Transactions ### Import Dependencies ```ts theme={null} import { createPublicClient, createWalletClient, hexToBigInt, http, parseEther, parseGwei, } from "viem"; import { privateKeyToAccount } from "viem/accounts"; import { celoAlfajores } from "viem/chains"; import "dotenv/config"; // use to read private key from environment variable ``` ### Create Public and Wallet Client ```ts theme={null} const PRIVATE_KEY = process.env.PRIVATE_KEY; /** * Boilerplate to create a viem client */ const account = privateKeyToAccount(`0x${PRIVATE_KEY}`); const publicClient = createPublicClient({ chain: celoAlfajores, transport: http(), }); const walletClient = createWalletClient({ chain: celoAlfajores, // Celo testnet transport: http(), }); ``` ### Function to Print Transaction Receipt ```ts theme={null} function printFormattedTransactionReceipt(transactionReceipt: any) { const { blockHash, blockNumber, contractAddress, cumulativeGasUsed, effectiveGasPrice, from, gasUsed, logs, logsBloom, status, to, transactionHash, transactionIndex, type, feeCurrency, gatewayFee, gatewayFeeRecipient } = transactionReceipt; const filteredTransactionReceipt = { type, status, transactionHash, from, to }; console.log(`Transaction details:`, filteredTransactionReceipt, `\n`); } ``` ### Code to Send Transaction Type (0) ```ts theme={null} /** - Transation type: 0 (0x00) - Name: "Legacy" - Description: Ethereum legacy transaction */ async function demoLegacyTransactionType() { console.log(`Initiating legacy transaction...`); const transactionHash = await walletClient.sendTransaction({ account, // Sender to: "0x70997970c51812dc3a010c7d01b50e0d17dc79c8", // Recipient (illustrative address) value: parseEther("0.01"), // 0.01 CELO gasPrice: parseGwei("20"), // Special field for legacy transaction type }); const transactionReceipt = await publicClient.waitForTransactionReceipt({ hash: await transactionHash, }); printFormattedTransactionReceipt(transactionReceipt); } ``` ### Code to Send Transaction Type (2) ```ts theme={null} /** * Transaction type: 2 (0x02) * Name: "Dynamic fee" * Description: Ethereum EIP-1559 transaction */ async function demoDynamicFeeTransactionType() { console.log(`Initiating dynamic fee (EIP-1559) transaction...`); const transactionHash = await walletClient.sendTransaction({ account, // Sender to: "0x70997970c51812dc3a010c7d01b50e0d17dc79c8", // Recipient (illustrative address) value: parseEther("0.01"), // 0.01 CELO maxFeePerGas: parseGwei("10"), // Special field for dynamic fee transaction type (EIP-1559) maxPriorityFeePerGas: parseGwei("10"), // Special field for dynamic fee transaction type (EIP-1559) }); const transactionReceipt = await publicClient.waitForTransactionReceipt({ hash: await transactionHash, }); printFormattedTransactionReceipt(transactionReceipt); } ``` ### Code to Send Transaction Type (123) ```ts theme={null} /** * Transaction type: 123 (0x7b) * Name: "Dynamic fee" * Description: Celo dynamic fee transaction (with custom fee currency) */ async function demoFeeCurrencyTransactionType() { console.log(`Initiating custom fee currency transaction...`); const transactionHash = await walletClient.sendTransaction({ account, // Sender to: "0x70997970c51812dc3a010c7d01b50e0d17dc79c8", // Recipient (illustrative address) value: parseEther("0.01"), // 0.01 CELO feeCurrency: "0x874069Fa1Eb16D44d622F2e0Ca25eeA172369bC1", // USDm fee currency maxFeePerGas: parseGwei("10"), // Special field for dynamic fee transaction type (EIP-1559) maxPriorityFeePerGas: parseGwei("10"), // Special field for dynamic fee transaction type (EIP-1559) }); const transactionReceipt = await publicClient.waitForTransactionReceipt({ hash: await transactionHash, }); printFormattedTransactionReceipt(transactionReceipt); } ```