> ## 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. # Place an order > Submits a BURN or MINT order to the current auction cycle. Returns 202 Accepted with the orderId and initial `pending` status. The order rests until the auction clears. The `idempotencyKey` you supply becomes the `orderId` for all subsequent lookups. Use a unique UUID v4 per order. Reusing a key with different parameters returns error 137004 (HTTP 409). BURN orders require `sourceWalletId` and `fiatAccountId`. MINT orders must omit those fields. Use the `orderType` discriminator to select the correct variant. ## OpenAPI ````yaml openapi/match.yaml post /v1/match/orders openapi: 3.1.0 info: title: Circle Match API description: > The Circle Match API provides endpoints for Circle Match, a periodic batch-auction venue that coordinates USDC burn demand with USDC mint demand for eligible Circle Mint customers. ## Authentication All REST endpoints require a Bearer token: ``` Authorization: Bearer ``` ## WebSocket Real-time auction state and account events are delivered over a persistent WebSocket connection at `wss://api.circle.com/v1/match/ws` (production) or `wss://api-sandbox.circle.com/v1/match/ws` (sandbox). Obtain a short-lived ticket with `POST /v1/match/ws/ticket`, then pass two `Sec-WebSocket-Protocol` values in the upgrade request: - `circle-match.v1` - `ticket.` — the ticket value, prefixed with `ticket.` After connection, subscribe to the `market` channel for public auction state or the `account` channel for private order and fill events. See the Circle Match WebSocket reference for the full protocol specification. ## Error codes | Code | HTTP | Description | |--------|------|-------------| | 136001 | 400 | Auction locked — cancellations and less-competitive fee changes not accepted | | 136002 | 400 | Auction settling — try again after settlement completes | | 137001 | 400 | Insufficient available balance | | 137002 | 400 | Invalid wallet | | 137003 | 400 | Wallet not found | | 137004 | 409 | Idempotency key reused with different parameters | | 137005 | 400 | Fee change not more competitive during lock window | | 137006 | 409 | Self-match violation — open order on opposite side of same auction | | 137007 | 400 | Invalid fiat account | | 137008 | 400 | Maximum orders per auction reached | | 137009 | 400 | Transaction limit exceeded | | 137010 | 400 | Entity not eligible for Circle Match | | 138001 | 400 | Withdrawal amount exceeds available balance | | 138002 | 400 | Withdrawal request invalid | | 138003 | 404 | No Circle Match account found for this entity | | 138004 | 400 | Invalid withdrawal destination | | 139001 | 400 | Circle Match wallet invalid | version: 1.0.0 servers: - url: https://api.circle.com description: Production - url: https://api-sandbox.circle.com description: Sandbox security: - BearerAuth: [] tags: - name: Account description: Account balance and activity summary - name: Orders description: Place, list, retrieve, cancel, and modify orders - name: Withdrawals description: Withdraw restricted mint-side USDC - name: WebSocket description: Obtain a WebSocket connection ticket paths: /v1/match/orders: post: tags: - Orders summary: Place an order description: >- Submits a BURN or MINT order to the current auction cycle. Returns 202 Accepted with the orderId and initial `pending` status. The order rests until the auction clears. The `idempotencyKey` you supply becomes the `orderId` for all subsequent lookups. Use a unique UUID v4 per order. Reusing a key with different parameters returns error 137004 (HTTP 409). BURN orders require `sourceWalletId` and `fiatAccountId`. MINT orders must omit those fields. Use the `orderType` discriminator to select the correct variant. operationId: placeOrder requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/PlaceOrderRequest' examples: burn_limit: summary: BURN limit order value: idempotencyKey: 550e8400-e29b-41d4-a716-446655440000 orderType: BURN amount: amount: '500.00' currency: USD feeBps: '5' postFillAction: roll sourceWalletId: '1000001234' fiatAccountId: 550e8400-e29b-41d4-a716-446655440001 mint_limit: summary: MINT limit order value: idempotencyKey: 661f9511-f30c-52e5-b827-557766551111 orderType: MINT amount: amount: '1000.00' currency: USD feeBps: '5' postFillAction: roll burn_market: summary: BURN market order (no fee ceiling) value: idempotencyKey: 772a0622-a41d-63f6-c938-668877662222 orderType: BURN amount: amount: '500.00' currency: USD postFillAction: cancel sourceWalletId: '1000001234' fiatAccountId: 550e8400-e29b-41d4-a716-446655440001 responses: '202': description: Order accepted and resting in the current auction content: application/json: schema: type: object required: - data properties: data: type: object required: - auctionId - orderId - status properties: auctionId: type: integer description: Auction cycle the order entered example: 42 orderId: type: string format: uuid description: >- Order identifier; equals the idempotencyKey you supplied example: 550e8400-e29b-41d4-a716-446655440000 status: type: string enum: - pending example: pending '400': description: >- Bad request. Error codes: `137001` — insufficient available balance; `137002` — invalid wallet; `137003` — wallet not found; `137007` — invalid fiat account; `137008` — maximum orders per auction reached, wait for the next cycle; `137009` — transaction limit exceeded; `137010` — entity not eligible for Circle Match. content: application/json: schema: $ref: '#/components/schemas/Error' '401': description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/Error' '409': description: >- Conflict. Error codes: `137004` — idempotency key reused with different parameters; `137006` — self-match violation, you already have an open order on the opposite side. content: application/json: schema: $ref: '#/components/schemas/Error' components: schemas: PlaceOrderRequest: description: >- Request body for placing a Circle Match order. Use `orderType` to select the variant: BURN orders require `sourceWalletId` and `fiatAccountId`; MINT orders omit those fields. oneOf: - $ref: '#/components/schemas/PlaceBurnOrderRequest' - $ref: '#/components/schemas/PlaceMintOrderRequest' discriminator: propertyName: orderType mapping: BURN: $ref: '#/components/schemas/PlaceBurnOrderRequest' MINT: $ref: '#/components/schemas/PlaceMintOrderRequest' Error: type: object required: - code - message properties: code: type: integer description: Circle error code example: 137001 message: type: string description: Human-readable error description example: Insufficient available balance PlaceBurnOrderRequest: description: Request body for placing a BURN order allOf: - $ref: '#/components/schemas/PlaceOrderBase' - type: object required: - sourceWalletId - fiatAccountId properties: orderType: type: string enum: - BURN sourceWalletId: type: string description: Circle Mint wallet ID that funds the burn example: '1000001234' fiatAccountId: type: string format: uuid description: Fiat account that receives settlement proceeds example: 550e8400-e29b-41d4-a716-446655440001 PlaceMintOrderRequest: description: Request body for placing a MINT order allOf: - $ref: '#/components/schemas/PlaceOrderBase' - type: object properties: orderType: type: string enum: - MINT PlaceOrderBase: type: object required: - idempotencyKey - orderType - amount - postFillAction properties: idempotencyKey: type: string format: uuid description: >- Unique UUID v4 per order. Becomes the orderId for all subsequent lookups. Reusing a key with different parameters returns error 137004. example: 550e8400-e29b-41d4-a716-446655440000 orderType: $ref: '#/components/schemas/OrderType' amount: allOf: - $ref: '#/components/schemas/Money' description: Amount to burn or mint. Minimum $100, must be a multiple of $100. feeBps: oneOf: - type: string - type: 'null' description: >- For BURN orders: maximum fee in basis points you are willing to pay. For MINT orders: minimum rebate in basis points you require. Omit or set to null for a market order that matches at any clearing fee. example: '5' postFillAction: $ref: '#/components/schemas/PostFillAction' OrderType: type: string description: Whether this is a BURN (USDC-to-USD) or MINT (USD-to-USDC) order enum: - BURN - MINT Money: type: object description: A monetary amount with its currency required: - amount - currency properties: amount: type: string description: Decimal amount as a string, rounded to 2 decimal places example: '500.00' currency: type: string description: ISO 4217 currency code example: USD PostFillAction: type: string description: | Action to take on unfilled remainder after an auction cycle closes. - `roll`: Carry remainder into the next auction as a new linked order. - `fallback`: Route remainder to standard Circle Mint. - `cancel`: Drop the unfilled remainder. enum: - roll - fallback - cancel securitySchemes: BearerAuth: type: http scheme: bearer ````