EVM Gasless (Universal Gasless)

Overview

New to EVM Gasless? See Universal Gasless in the Help Center for a product introduction, then use this guide for the setup and API behavior. EVM Gasless, also known as Universal Gasless, lets a vault account on an EVM chain send tokens and call contracts without holding the native asset. The vault account signs a meta-transaction, and a relay vault account submits it on-chain and pays the gas. It supports any ERC-20, ERC-721, or ERC-1155 token on the Universal Gasless integrated chains. It does not relay native asset transfers such as ETH. For how gasless compares across chains, see the Gasless Transactions Overview.

How it works

EVM Gasless uses EIP-7702 to upgrade a vault account’s address into a smart contract wallet that accepts relayed calls. The upgrade happens once per vault account per chain, during that account’s first gasless transaction. That first transaction carries one additional action (the delegation), and later transactions from the same account are single meta-transactions. The upgrade does not change the vault account’s address, keys, or balances. After the upgrade, the Console shows an indicator next to the vault account.

Choose a relay

The relay is the vault account that pays gas for your gasless transactions.

Console option	Who pays gas	Setup
This workspace	A vault account in your own workspace	Self-serve. You keep the relay vault account funded with the native asset.
External workspace	A vault account in another Fireblocks workspace	Requested through your Customer Success Manager and approved by the other workspace’s Admin.
Fireblocks	A Fireblocks-operated relay	Paid add-on. See Using the Fireblocks Gasless Relay.

Use a Wallet Pool as the relay

A single relay vault account has one nonce stream, so it becomes a bottleneck as gasless volume grows. With This workspace as the relay, you can select a Wallet Pool instead of a single vault account, and Fireblocks spreads relaying across the pool’s members. A relay pool needs more native-asset headroom per member than a transfer pool, because the first transaction from each vault account also pays for the EIP-7702 upgrade. See Wallet Pools use cases.

Relay for other workspaces

To pay gas for other workspaces, go to Settings > Become a gasless relayer. A relay workspace must use an API Co-signer to sign relay transactions. See Configuring your workspace as a relay provider.

Step 1. Configure EVM Gasless in the Console

Go to Settings > Initiate gasless transactions, turn on EVM, select Universal gasless and the relay, then select the default mode. See Configuring Universal Gasless transactions for the full steps.

Mode	Behavior
On by default	Eligible transactions are gasless unless the request sets `useGasless: false`.
Off by default	Transactions pay their own fee unless the request sets `useGasless: true`.
None	Gasless is off for every vault account and cannot be requested per transaction.

Step 2. Add Policy rules

EVM Gasless adds transactions that your Policy must allow:

Rule	Where	Needed for
Vault account upgrade, source = the vault accounts that send gasless, action = Allow	Your workspace	Every relay option
Contract call, initiator = Gasless-Orchestrator, designated signer = Single user or Multiple users	The relay’s workspace	This workspace as the relay

For the Contract call rule:

Initiator. Select Gasless-Orchestrator explicitly. This rule is required even if you already have a Contract call rule whose initiator is any, because a rule that generalizes the initiator does not cover Gasless-Orchestrator.
Designated signer. Gasless-Orchestrator cannot sign, so the designated signer cannot be the initiator. Set Designated signer to Single user or Multiple users, not Initiator.

Step 3. Send a transaction

Submit a standard transfer with Create a new transaction. When the mode is On by default, you need no extra fields. POST /v1/transactions

{
  "assetId": "USDC",
  "amount": "250",
  "source": {
    "type": "VAULT_ACCOUNT",
    "id": "42"
  },
  "destination": {
    "type": "ONE_TIME_ADDRESS",
    "oneTimeAddress": {
      "address": "0x..."
    }
  },
  "useGasless": true // Optional - Overrides the workspace default for this transaction
}

Field notes:

useGasless: set true to request gasless when the mode is Off by default, or false to pay the fee directly when it is On by default. Omit it to follow the workspace default. It has no effect when the mode is None.
source: the vault account needs the token balance only. It does not need the native asset.
assetId: a token on a supported chain. Native asset transfers are not relayed.

Step 4. Confirm the relay paid

Get a transaction or read the transaction webhook. A gasless transaction carries gaslessInfo, and feeInfo reports who paid.

{
  "id": "5c1f...",
  "status": "COMPLETED",
  "assetId": "USDC",
  "gaslessInfo": {
    "isMetaTx": true,
    "relayTenantId": "8a2e...",
    "relayTenantName": "Acme Treasury",
    "relayVaultAccountId": "7"
  },
  "feeInfo": {
    "paidByRelay": true,
    "relayType": "LOCAL",
    "relayId": "7"
  }
}

Field	Description
`gaslessInfo.isMetaTx`	`true` when the transaction was relayed. `gaslessInfo` is returned only for relayed transactions.
`gaslessInfo.relayVaultAccountId`	The relay vault account that paid the gas.
`feeInfo.paidByRelay`	`true` when the relay paid the fee.
`feeInfo.relayType`	`LOCAL` for a relay in your workspace, `THIRD_PARTY` for an external workspace or the Fireblocks relay.
`feeInfo.relayName`	The relay’s workspace name. Returned for `THIRD_PARTY` relays only.

For relayed transactions, the deprecated top-level fee field is omitted. Read feeInfo instead.

Troubleshooting

Symptom	Cause	Fix
Error `1455` “Missing Gasless configuration”	Gasless is not set up for this workspace or asset	Configure a relay in the Console, or send without `useGasless: true`.
First transaction from a vault account is blocked by Policy	No Vault account upgrade rule covers the account	Add the rule from Step 2.
Relay transaction is blocked by Policy in the relay workspace	The Contract call rule does not name Gasless-Orchestrator, or its designated signer is Initiator	Fix the relay workspace’s rule as in Step 2.

See API error codes for the full list.

Gasless Transactions Overview: compare gasless mechanisms across chains.
Wallet Pools: spread relaying across several vault accounts.
Sweep to omnibus: use EVM Gasless to sweep tokens from deposit vault accounts.
Work with Gas Station: fund vault accounts for native asset transfers.

Get Started

Workspace & Security

Webhooks

Direct Custody Wallets

Manage Wallets

Embedded Wallets

Transactions

Gas Management

Treasury & Trading

Smart Contracts & Tokenization

Assets & NFTs

Compliance

Payments

Offchain Signing

API Co-Signers

Key Link

Integrations

Overview

How it works

Choose a relay

Use a Wallet Pool as the relay

Relay for other workspaces

Step 1. Configure EVM Gasless in the Console

Step 2. Add Policy rules

Step 3. Send a transaction

Step 4. Confirm the relay paid

Troubleshooting

​Overview

​How it works

​Choose a relay

​Use a Wallet Pool as the relay

​Relay for other workspaces

​Step 1. Configure EVM Gasless in the Console

​Step 2. Add Policy rules

​Step 3. Send a transaction

​Step 4. Confirm the relay paid

​Troubleshooting

​Related

Overview

How it works

Choose a relay

Use a Wallet Pool as the relay

Relay for other workspaces

Step 1. Configure EVM Gasless in the Console

Step 2. Add Policy rules

Step 3. Send a transaction

Step 4. Confirm the relay paid

Troubleshooting

Related