# Swapper On-ramp

On-ramp from fiat or any supported EVM chain into Fast network — via CLI or AllSet SDK.

## What the On-ramp Does

The on-ramp bridges funds from the outside world into Fast:

* **Fiat → Crypto**: Buy USDC with a credit card or bank transfer; USDC is then bridged to Fast as `fastUSDC`
* **EVM → Fast**: Deposit USDC from any supported EVM chain (Arbitrum, Base, Ethereum) directly into Fast via the AllSet bridge

Funds arrive on Fast as `fastUSDC` and are immediately usable for agent payments, x402 requests, or cross-chain workflows. No exchange account or CEX KYC is required for EVM deposits.

## How to Use

### CLI

The [Fast CLI](https://github.com/fastxyz/fast-sdk/blob/main/app/cli/README.md) provides funding flows for both crypto deposits and fiat on-ramp entry points. In the current monorepo, `fast fund crypto` covers EVM-to-Fast deposits, while `fast fund fiat` returns a mainnet on-ramp URL for the selected Fast address.

The CLI wraps the underlying SDK flows where appropriate. For scripted integrations or custom orchestration, use the SDK directly.

### SDK

Use `@fastxyz/allset-sdk` to execute deposits programmatically. The SDK provides `createEvmWallet()`, `createEvmExecutor()`, and `executeDeposit()` for bridging from EVM chains to Fast. All functions are pure — you pass all addresses and RPC URLs explicitly.

For complete API documentation and runnable code examples, see the [AllSet SDK README on GitHub](https://github.com/fastxyz/fast-sdk/blob/main/packages/allset-sdk/README.md). See the [AllSet SDK reference](/sdk-references/core-sdk-execution/allset-sdk.md) for an overview of how deposits, withdrawals, and intents work.

## How AllSet SDK Enables the Bridge

The AllSet bridge is a two-step protocol built into `@fastxyz/allset-sdk`:

1. **Approve + Deposit** (EVM side): `executeDeposit` submits an ERC-20 `approve` (if needed) and a deposit transaction to the AllSet bridge contract on the source EVM chain
2. **Mint on Fast** (Fast side): The AllSet relayer observes the EVM event, cross-signs the proof, and mints `fastUSDC` to the receiver's Fast address

This means:

* No liquidity fragmentation — funds arrive as Fast-native USDC (`fastUSDC`)
* No waiting for finality — Fast settlement is sub-second once the EVM deposit confirms
* No user-controlled bridging keys — the relayer handles cross-chain proof generation

For advanced intent-based flows (custom calldata, deposit-back, revoke), see `executeIntent()` in the [AllSet SDK reference](/sdk-references/core-sdk-execution/allset-sdk.md).

## Supported Tokens and Chains

### EVM Source Chains

| Chain            | Chain ID | USDC Address                                 | Status |
| ---------------- | -------- | -------------------------------------------- | ------ |
| Ethereum Sepolia | 11155111 | `0x...` (test USDC)                          | ✅      |
| Arbitrum Sepolia | 421614   | `0x75faf114eafb1bdbe2f0316df893fd58ce46aa4d` | ✅      |
| Arbitrum         | 42161    | `0xaf88d065e77c8cC2239327C5EDb3A432268e5831` | ✅      |
| Base             | 8453     | `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913` | ✅      |
| Ethereum         | 1        | `0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48` | ✅      |

### Fast Tokens (on Fast network)

| Token      | Description                 | Minted via AllSet? |
| ---------- | --------------------------- | ------------------ |
| `fastUSDC` | Fast-native USDC (1:1 USDC) | ✅ (from EVM USDC)  |
| `testUSDC` | Testnet equivalent          | ✅ (from test USDC) |

### Fiat On-ramp

| Method        | Region     | Token Out     | Status      |
| ------------- | ---------- | ------------- | ----------- |
| Credit Card   | US, EU, UK | USDC/testUSDC | Coming soon |
| Bank Transfer | US, EU     | USDC/testUSDC | Coming soon |

> Fiat on-ramp is integrated via third-party providers. The current CLI exposes the entry point, while broader SDK wrappers and provider coverage continue to evolve. Track the high-level roadmap in the [Funding Abstraction](/sdk-references/funding-abstraction.md) overview.

## SDK Reference

| SDK                                                                                                  | Use for                                      |
| ---------------------------------------------------------------------------------------------------- | -------------------------------------------- |
| [@fastxyz/allset-sdk](https://github.com/fastxyz/fast-sdk/blob/main/packages/allset-sdk/README.md)   | EVM ↔ Fast deposits, withdrawals, intents    |
| [@fastxyz/sdk](https://github.com/fastxyz/fast-sdk/blob/main/packages/fast-sdk/README.md)            | Fast address conversion, transaction signing |
| [@fastxyz/x402-client](https://github.com/fastxyz/fast-sdk/blob/main/packages/x402-client/README.md) | Pay for x402 APIs with Fast or EVM funds     |


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