> ## 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.

# How-to: Cancel and modify orders

> Cancel a single resting order, cancel all orders in an auction, or change an order's fee limit before the auction clears.

Match provides three mutation endpoints for resting orders: cancel a single
order, cancel all of your orders in the current auction, or modify an order's
fee limit. These operations are available at any time during an auction cycle
with one exception: the lock window that opens before clearing imposes
additional constraints.

<Warning>
  During the lock window, cancellations are blocked and only fee changes that
  make an order more competitive are accepted. Attempting to cancel returns
  error 136001. Attempting to make a fee less competitive returns error 137005.
  New orders are still accepted during the lock window. For a full explanation
  of the lock window and auction lifecycle, see [How Match
  works](/circle-match/concepts/how-it-works).
</Warning>

## Prerequisites

Before you begin, ensure that you've:

* Obtained a Circle API key with Match access
* Placed at least one order that is in `pending` status (see
  [Place and manage orders](/circle-match/howtos/place-orders))
* Retrieved the `auctionId` and `orderId` for the order you want to act on

## Steps

### Step 1. Cancel a single order

Send a `POST` request to `/v1/match/orders/cancel` with the `auctionId` and
`orderId` of the resting order.

```bash theme={null}
curl -X POST https://api-sandbox.circle.com/v1/match/orders/cancel \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "auctionId": 42,
    "orderId": "550e8400-e29b-41d4-a716-446655440000"
  }'
```

A successful response returns status `cancelled`:

```json theme={null}
{
  "data": {
    "auctionId": 42,
    "orderId": "550e8400-e29b-41d4-a716-446655440000",
    "status": "cancelled"
  }
}
```

If the lock window is open, the request is rejected with error 136001. Wait for
the auction to clear and retry against the next auction cycle if the order rolls
over.

### Step 2. Cancel all orders

To cancel every resting order you have in the current auction, send a `POST`
request to `/v1/match/orders/cancel-all`. No request body is required.

```bash theme={null}
curl -X POST https://api-sandbox.circle.com/v1/match/orders/cancel-all \
  -H "Authorization: Bearer $API_KEY"
```

A successful response lists all cancelled order IDs:

```json theme={null}
{
  "data": {
    "auctionId": 42,
    "orderIds": [
      "550e8400-e29b-41d4-a716-446655440000",
      "661f9511-f30c-52e5-b827-557766551111"
    ],
    "status": "cancelled"
  }
}
```

If you have no resting orders in the current auction, `orderIds` is an empty
array and the call still returns 200. As with single-order cancellation, this
endpoint returns error 136001 when the lock window is open.

### Step 3. Modify an order's fee

Use `POST /v1/match/orders/modify` to change the fee limit on a resting order.
Only the fee changes; the order remains in `pending` status with its original
size and side.

The competitiveness direction differs by order type:

* **BURN orders:** a higher `feeBps` is more competitive (willing to pay a
  larger fee)
* **MINT orders:** a lower `feeBps` is more competitive (requiring a smaller
  rebate)

Outside the lock window, you can move the fee in either direction. During the
lock window, the new `feeBps` must be more competitive than the current value.
Submitting a less competitive fee during the lock window returns error 137005.

To convert a limit order to a market order, set `feeBps` to `null`.

```bash theme={null}
curl -X POST https://api-sandbox.circle.com/v1/match/orders/modify \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "auctionId": 42,
    "orderId": "550e8400-e29b-41d4-a716-446655440000",
    "feeBps": "3"
  }'
```

A successful response confirms the order is still `pending` with the updated
fee:

```json theme={null}
{
  "data": {
    "auctionId": 42,
    "orderId": "550e8400-e29b-41d4-a716-446655440000",
    "status": "pending"
  }
}
```

## Error reference

| Code | HTTP | Meaning |
| - | - | - |
| 136001 | 400 | The auction is locked. Cancellations are not accepted until the auction clears. |
| 136002 | 400 | The auction is settling the previous batch. Try again after settlement completes. |
| 137005 | 400 | During the lock window, a fee change must improve competitiveness. The submitted fee is less competitive than the current fee. |