> ## 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.

# Error codes

> HTTP status codes and numeric error codes returned by Managed Payments endpoints, with causes and remediation steps

Errors from Managed Payments endpoints use a flat response and the following
endpoint-specific numeric codes. For general errors returned by any Circle API,
see [API errors](/api-reference/errors).

## Error response shape

Managed Payments endpoints return errors as a flat object:

```json theme={null}
{
  "code": 1177,
  "message": "The purposeOfTransfer field is missing or invalid",
  "errors": []
}
```

## Common error codes

| Status code | Error code | Description |
| - | - | - |
| `500` | `-1` | Circle couldn't process the request. Retry later. If it fails again, contact Circle support with the `errId`. |
| `401` | `1` | The `Authorization` header is missing or malformed. Pass the API key as a `Bearer` token. |
| `400` | `2` | A request field is missing or has the wrong type. Check `message` for the field name. |
| `403` | `3` | The API key can't use this resource, or your entity doesn't support it. |
| `401` | `4` | The API key is invalid, expired, or inactive. Check the key. |
| `429` | `5` | Too many requests. Wait, then retry. |

## Create a payment intent

Codes returned by `POST /v1/paymentIntents`.

| Status code | Error code | Description |
| - | - | - |
| `400` | `1127` | Send one blockchain payment method. The value can't be `null` or contain more than one method. |
| `400` | `1128` | The `expiresOn` value is missing, malformed, in the past, or more than 24 hours after creation. Set it to a valid timestamp no more than 24 hours from now. |
| `400` | `1130` | The currency and blockchain pair isn't supported. Use a supported pair or confirm support with Circle. |
| `400` | `1131` | The intent and settlement currency pair isn't supported. Use a supported pair. |
| `400` | `1132` | The amount is `0`, less than `0`, or has too many decimal places. Send a valid amount. |
| `400` | `1177` | `purposeOfTransfer` is missing or invalid. Enforcement depends on account configuration; Circle Singapore (`CIRCLE_SG`) and certain Circle LLC (`CIRCLE_INC`) accounts require it. See [payment reason codes](/cpn/references/errors/payment-reason-codes). |
| `400` | `1069` | The merchant doesn't own the `merchantWalletId`, or the wallet wasn't found. Check the ID. |
| `409` | `1083` | The idempotency key is bound to another request. Fetch that result, or use a new key for a new request. |

## Refund a payment intent

Codes returned by `POST /v1/paymentIntents/{paymentIntentId}/refund`.

| Status code | Error code | Description |
| - | - | - |
| `400` | `1130` | The refund currency and blockchain pair isn't supported. Use a supported pair. |
| `400` | `1137` | The intent has no completed crypto payment, or the intent failed. It can't be refunded. |
| `400` | `1138` | Use the source currency from the first payment or settlement. |
| `400` | `1141` | The refund currency must match the first payment. |
| `400` | `1142` | The amount is more than the balance that can be refunded. Reduce it. |
| `400` | `1145` | The 30-day refund window has passed. Handle the refund outside this API. |
| `400` | `1146` | A crypto payment is still pending. Wait for it to finish, then retry. |
| `400` | `1165` | Set one destination: a raw `address` and `chain`, or an `addressBookId`. |
| `400` | `1166` | Use an address book entry owned by the merchant's legal entity. Circle Singapore (`CIRCLE_SG`) requires this. |
| `400` | `1167` | The address book entry isn't active. Wait for approval, then retry. |
| `400` | `1168` | The crypto payment can't be refunded in its current state. Check the state before you retry. |
| `400` | `1169` | The total refund is more than the crypto payment. Reduce the amount. |
| `400` | `1170` | The payment doesn't belong to this intent. Use the correct payment. |
| `400` | `1178` | The refund amount must be greater than `0`. |
| `404` | `1126` | The payment intent wasn't found. Check `paymentIntentId`. |
| `404` | `1164` | The address book entry wasn't found. Check `addressBookId`. |

<Note>
  Circle Singapore (`CIRCLE_SG`) doesn't support a raw refund destination. Use
  an `addressBookId` or set `useOriginalSender: true`.
</Note>

## Address book recipients

Codes returned when creating or updating an address book recipient.

| Status code | Error code | Description |
| - | - | - |
| `400` | `2024` | Circle Singapore (`CIRCLE_SG`) recipients require `identity`. |
| `400` | `2025` | Circle Singapore (`CIRCLE_SG`) recipients require `ownership`. |
| `400` | `2026` | A hosted-custody recipient requires `ownership.custody.vaspId`. |
| `400` | `2027` | `ownership.type` isn't supported. Circle Singapore (`CIRCLE_SG`) recipients must use `third_party`. |
| `400` | `2028` | `ownership.custody.type` isn't supported for this entity. |
| `400` | `2029` | Set `ownership.custody`. |
| `400` | `2030` | `ownership.custody.vaspId` isn't a known VASP. |
| `400` | `2031` | `identity.type` must be `individual` or `business`. |
| `400` | `2032` | An individual recipient requires a first name in `identity.individual`. |
| `400` | `2033` | An individual recipient requires a last name in `identity.individual`. |
| `400` | `2034` | A business recipient requires a business name in `identity.business`. |
| `400` | `2035` | A self-hosted recipient must not set `ownership.custody.vaspId`. |
| `400` | `2038` | A self-hosted Circle Singapore (`CIRCLE_SG`) recipient requires `metadata.email`. Its `ownership.custody.type` is `self_hosted`. |
| `400` | `2048` | A self-hosted individual recipient requires `identity.individual`. |
| `400` | `2049` | A self-hosted business recipient requires `identity.business`. |

## Stablecoin payouts

Codes returned by stablecoin payout endpoints.

| Status code | Error code | Description |
| - | - | - |
| `400` | `5000` | The travel rule `identity.type` must be `individual` or `business`. |
| `400` | `5002` | The payout amount must be greater than `0`. |
| `400` | `5003` | The destination address is inactive. |
| `400` | `5004` | The destination address wasn't found. |
| `400` | `5005` | The source wallet wasn't found. |
| `400` | `5006` | The source wallet lacks funds. Check that its wire has settled. |
| `400` | `5007` | The currency isn't supported for this operation. |
| `400` | `5011` | The destination address is invalid. If you just added it, wait up to 24 hours before using it. |
| `400` | `5015` | The destination blockchain is invalid for the currency. |
| `400` | `5020` | `purposeOfTransfer` is missing or invalid on a payout. Enforcement depends on account configuration; Circle Singapore (`CIRCLE_SG`), Circle SAS (`CIRCLE_FR`), and certain Circle LLC (`CIRCLE_INC`) accounts require it. See [payment reason codes](/cpn/references/errors/payment-reason-codes). |
| `400` | `5021` | The destination address isn't associated with the source sub-wallet. |

## Create a withdrawal

Codes returned when `POST /v1/accounts/withdrawals` sends fiat to a linked bank
account.

| Status code | Error code | Description |
| - | - | - |
| `400` | `5002` | The payout amount must be greater than `0`. |
| `400` | `5006` | The source wallet lacks funds. Add funds or wait for settlement, then retry. |
| `400` | `5007` | The currency isn't supported. Use a supported currency. |
| `400` | `5016` | The fiat account can't use this transfer type. Check what the account supports. |
| `400` | `5017` | The transfer limit was reached. Reduce the amount or wait for the limit to reset. |
| `400` | `5019` | The payout limit was reached. Reduce the amount or wait for the limit to reset. |
| `400` | `1112` | The fiat account wasn't found. Check that it is registered. |
| `400` | `1100` | The fiat account type is invalid for payouts. |
| `400` | `1089` | The source account wasn't found. Verify the source account ID. |

## Asynchronous withdrawal outcomes

A valid `POST /v1/accounts/withdrawals` call returns `201` at once with
`data.status: "pending"`. Get the final result from the `payouts` webhook or
`GET /v1/accounts/withdrawals/{id}`. Store `trackingRef` to match the wire on
your bank statement.

| `data.status` | `data.errorCode` | Description |
| - | - | - |
| `pending` | (omitted) | The withdrawal was accepted and is processing. Wait for the webhook. |
| `complete` | (omitted) | USD was sent to the bank. Record `trackingRef` for reconciliation. |
| `failed` | `insufficient_funds` | The account ran out of funds after acceptance. Retry once funds are replenished. |
| `failed` | `transaction_denied` | A policy or risk check denied the wire. Contact Circle support. Don't retry on your own. |
| `failed` | `transaction_failed` | Circle or the bank couldn't process the wire. Retry once. If it fails again, contact support with the withdrawal ID. |
| `failed` | `transaction_returned` | The bank sent the wire back. Fix the bank details, register the account again, and retry. |
| `failed` | `bank_transaction_error` | The bank reported an error. Contact your bank and Circle support. |
| `failed` | `fiat_account_limit_exceeded` | The bank account reached its inbound limit. Ask the bank to raise it, then retry. |
| `failed` | `invalid_bank_account_number` | The bank account number is wrong. Register the account again with the right number. |
| `failed` | `invalid_ach_rtn` | The ACH routing number is invalid. Circle Singapore (`CIRCLE_SG`) accounts use wires only. Use the right SWIFT/BIC. |
| `failed` | `invalid_wire_rtn` | The SWIFT/BIC is invalid. Register the account again with the right value. |
| `failed` | `vendor_inactive` | A bank used by Circle is down for now. Retry in 5 to 10 minutes. Contact support if it still fails. |
| `failed` | `payout_canceled` | The withdrawal was canceled before it settled. Submit a new withdrawal if you still need it. |
| `failed` | `invalid_travel_rule_identity` | The travel rule identity failed validation. Circle Singapore (`CIRCLE_SG`) requires it. Correct the details and retry. |
| `failed` | `intermediary_bank_required` | The wire needs an intermediary bank. Add intermediary bank details to the account, then retry. |

## Wire accounts

| Status code | Error code | Description |
| - | - | - |
| `400` | `1106` | Set `billingDetails.district` for addresses in the United States or Canada. Use the state or province code. |

## Idempotency

An idempotency key stays bound to its record and doesn't expire. The same body
returns the first record. A new body returns `409` with code `1083`. Use a new
UUID for each new request.