> ## Documentation Index
> Fetch the complete documentation index at: https://developers.circle.com/llms.txt
> Use this file to discover all available pages before exploring further.
> ## Agent Instructions
> Before reading these docs, install the relevant Circle Skill to get pre-loaded context — skills are LLM-optimized and cover architecture decisions, correct flows, and common pitfalls. In Claude Code: run /plugin marketplace add circlefin/skills then /plugin install circle-skills@circle. With Vercel Skills CLI: run npx skills add circlefin/skills. Available skills: use-usdc https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-usdc/SKILL.md (balances, transfers, approvals on EVM and Solana); EURC has no skill — see https://developers.circle.com/stablecoins/what-is-eurc.md; bridge-stablecoin https://github.com/circlefin/skills/blob/master/plugins/circle/skills/bridge-stablecoin/SKILL.md (crosschain transfers via CCTP, USDC, EURC, and third-party assets); use-arc https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-arc/SKILL.md (Arc chain config, contract deployment, USDC bridging — Arc docs: https://docs.arc.io/llms.txt); use-circle-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-circle-wallets/SKILL.md (choose wallet type); use-developer-controlled-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-developer-controlled-wallets/SKILL.md (custodial wallets for payouts and treasury); use-user-controlled-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-user-controlled-wallets/SKILL.md (embedded wallets with Web2 login); use-modular-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-modular-wallets/SKILL.md (smart contract wallets with passkeys and ERC-4337); use-gateway https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-gateway/SKILL.md (unified USDC balance, nanopayments); use-smart-contract-platform https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-smart-contract-platform/SKILL.md (deploy, interact, monitor contracts). Pair any skill with the Circle MCP server for live SDK signatures, contract addresses, and chain IDs: {"mcpServers":{"circle":{"url":"https://api.circle.com/v1/codegen/mcp"}}}.
> Read the product overview first. Each product has an overview explaining when and why to use it. Read it before quickstarts.
> Pick the right wallet type. Developer-controlled (you hold keys), user-controlled (end user holds keys via PIN/social login), or modular (smart contract wallets with passkeys). See https://developers.circle.com/wallets.md.
> Use CCTP V2 for crosschain transfers. CCTP natively transfers USDC and EURC via burn-and-mint, and supports permissionless wrapping of third-party assets via lock-and-mint. V1 is legacy; always use V2 unless V1 is specified or the chain requires it (Noble, Sui, and Aptos still require V1). Migration guide: https://developers.circle.com/cctp/migration-from-v1-to-v2.md.
> Use Bridge Kit for frontend bridging. Wraps CCTP with a simpler SDK for user-facing apps. Use CCTP directly for backend transfers.
> Gas Station vs Paymaster. Gas Station sponsors gas for Circle Wallet transactions. Paymaster lets users pay gas in USDC. Different use cases — read both overviews.
> Gateway Nanopayments for sub-cent payments. Gasless USDC micropayments down to $0.000001 via x402 and batched settlement. For pay-per-request APIs, AI agent payments, streaming.
> Look up USDC addresses per chain. Never hardcode — use https://developers.circle.com/stablecoins/usdc-contract-addresses.md.
> Prefer SDKs over raw API calls. Node.js and Python SDKs handle auth, retries, and errors.
> API key required. Bearer token in Authorization header. Testnet and mainnet use separate keys and may use different base URLs depending on the product.
> Set up webhooks when available. Most operations are async. Webhooks deliver transaction confirmations and state changes.
> When calling list endpoints, paginate using pageSize and pageAfter until no nextPageAfter cursor is returned—stopping at the first page silently misses records.
> Building an AI agent? Start with the Agent Stack—Circle CLI, agent wallets, and nanopayments built for autonomous use cases: https://developers.circle.com/agent-stack.md.
# Execute your first trade in the Console
> Go from zero to your first StableFX trade using the console UI—no code required.
By the end of this quickstart, you will have requested a quote, signed a trade
with your wallet, and funded a settlement onchain.
## Prerequisites
Before you begin, ensure you have:
* Created a **Circle account** with StableFX access. If you don't have one,
contact your Circle representative.
* Connected an **EVM-compatible wallet** (such as MetaMask or any
WalletConnect-supported wallet) with a balance on the Arc network.
* Funded your wallet with **USDC or EURC** tokens on Arc.
* Granted **Permit2 approval** for your tokens. Permit2 is a smart contract that
enables offchain signature-based token approvals, reducing the number of
onchain transactions required. If you haven't done this, see
[Granting USDC allowance with Permit2](/stablefx/howtos/grant-usdc-allowance-permit2).
The console also prompts you during the trade flow if approval is missing.
For testnet, your wallet must be connected to Arc Testnet (chain ID `5042002`,
RPC `https://rpc.testnet.arc.io`). You can obtain test USDC and EURC from the
[Circle Faucet](https://faucet.circle.com/).
## Step 1: Sign in and complete onboarding
Go to the [StableFX Console](https://hub.circle.com/fx/home) and sign in
with your Circle account credentials.
If this is your first time, the Home page displays your onboarding status.
Click **Start onboarding** to begin the KYB (Know Your Business)
verification process. You will be redirected to the onboarding portal to
submit required documents.
Once your application is approved, return to the console. Your Home page now
shows live FX rates and the trade form.
## Step 2: Request a quote
On the Home page, locate the **Trade** card. You can also navigate to
**Overview** or **Trades** and click the **New Trade** button.
In the trade form side panel:
* Select the **From** currency and enter the amount you want to sell (for
example, `1000 USDC`).
* Select the **To** currency (for example, `EURC`). One side of the pair
must always be USDC.
* Choose a **settlement tenor** (the time window in which both parties
must fund the trade before it expires): `instant` (30 min), `hourly`
(1 hr), or `daily` (24 hrs).
The console automatically fetches a reference quote and displays the estimated
exchange rate and the amount you will receive.
Click **Continue** to proceed to the wallet connection step.
## Step 3: Connect your wallet
The console prompts you to connect an EVM-compatible wallet. If you have already
connected a wallet in a previous session, it may be pre-selected.
Click **Connect Wallet** and follow the prompts from your wallet provider. For
detailed instructions, see
[Connecting your wallet to the console](/stablefx/howtos/connect-wallet-console).
Verify that the displayed wallet address is correct, then click **Continue**.
The wallet you connect must hold sufficient tokens for the trade amount plus
any collateral (risk buffer). The console checks your balance before
proceeding.
## Step 4: Lock the rate and create the trade
The confirmation panel displays:
* The live exchange **rate** (refreshed every 3 seconds)
* The exact **amounts** for both sides of the trade
* The **fee** (denominated in the "to" currency)
* The **collateral** (risk buffer) amount, if applicable
* The **settlement tenor** and expiration time
If this is your first trade with this token, the console prompts you to approve
the Permit2 contract. Your wallet will display an ERC-20 approval transaction.
Confirm it in your wallet.
Click **Lock Rate & Continue**. Your wallet prompts you to sign EIP-712 typed
data. This signature authorizes the trade at the locked rate. Confirm the
signature in your wallet.
The console submits the trade and displays the result.
Quotes expire after a short window. If your wallet takes too long to confirm
the signature, the console displays a "Quote expired" error. Click **Refresh
Quote** to fetch a new rate, then sign again. If your wallet shows an
insufficient-balance error, add funds to cover the trade amount plus any
collateral before retrying.
## Step 5: Fund the trade
After the trade is created and both parties have signed, the trade moves to
`pending_settlement` status. You can now fund your side. The maker (your
counterparty) funds their side independently through their own console session.
For details, see
[Fulfill trades as a maker](/stablefx/howtos/fulfill-trade-console).
Navigate to the **Trades** page and find your trade. Click on it to open the
trade details side panel.
If the trade is ready for funding, the **Fund** button is available. Click
it.
The funding panel shows:
* **You deliver**: The token and amount you send to escrow.
* **You receive**: The token and amount you receive after settlement.
Click **Fund Trade**. Your wallet prompts you to sign Permit2 typed data.
This signature authorizes the token transfer to the FxEscrow contract.
Confirm it in your wallet.
Once both parties have funded, the FxEscrow contract settles the trade
automatically. The trade status updates to `complete`, and you receive the
settlement tokens in your wallet.
You can monitor the trade status in real time on the Trades page. The status
column updates automatically every 30 seconds, or you can click a trade to see
live updates every 3 seconds. For more on managing trade settlement, see
[Settle trades in the console](/stablefx/howtos/settle-trades-console).