> ## 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. # WebSocket reference > Complete reference for the Match WebSocket protocol, including connection setup, session frames, client messages, channel events, and reconnection behavior. The Match WebSocket API delivers real-time auction state and account updates over a persistent connection. All monetary values in WebSocket events are integer cents, not the REST `Money` object. For example, \$10.00 is represented as `1000`. ## Connection Connect by sending a WebSocket upgrade request to the appropriate endpoint. | Environment | Endpoint | | ----------- | ------------------------------------------ | | Production | `wss://api.circle.com/v1/match/ws` | | Sandbox | `wss://api-sandbox.circle.com/v1/match/ws` | Include both of the following protocol values in the `Sec-WebSocket-Protocol` header of the upgrade request: * `circle-match.v1` * `ticket.`: replace `` with the ticket token from `POST /v1/match/ws/ticket` ## Authentication Obtain a WebSocket ticket before opening the connection. **Endpoint:** `POST /v1/match/ws/ticket` No request body is required. The response contains a short-lived, single-use token: ```json theme={null} { "data": { "ticket": "eyJ..." } } ``` Obtain the ticket immediately before opening the socket. The server validates the ticket during the upgrade handshake. An invalid, expired, or missing ticket returns HTTP 401 and the connection is not established. ## Session frames The server sends the following session-level frames to the client. | Frame type | When sent | Fields | | ------------ | -------------------------------------------------- | ------------------------------------------------------------- | | `hello` | Immediately after a successful upgrade | `type: "hello"`, `entityId` (string), `serverTime` (ISO 8601) | | `keepalive` | Periodically while connected | `type: "keepalive"`, `serverTime` (ISO 8601) | | `subscribed` | After a subscribe message is acknowledged | `type: "subscribed"`, `channel` (`"market"` or `"account"`) | | `error` | On an invalid subscription or authentication error | `type: "error"`, `channel` (string or null), `error` (string) | ## Client messages Send subscribe messages to the server after receiving the `hello` frame. You can subscribe to multiple channels in a single session. | Message type | Fields | Notes | | ------------ | ---------------------------------------------------------- | ------------------------------------------------------------ | | `subscribe` | `type: "subscribe"`, `channel` (`"market"` or `"account"`) | Send after `hello`. Multiple subscribe messages are allowed. | ## Market channel The market channel is public and delivers real-time auction state. **Subscribe:** ```json theme={null} { "type": "subscribe", "channel": "market" } ``` ### Market channel events | Event type | When sent | Key fields | | -------------------- | ---------------------------------- | -------------------------------------------------------------------------------------------------------------- | | `snapshot` | On subscribe | All fields listed in the [market channel fields](#market-channel-fields) table | | `auction_opened` | A new auction cycle starts | `auctionId`, `lockAt` (ISO 8601), `clearAt` (ISO 8601), `auctionIntervalNs` (integer, nanoseconds) | | `auction_locked` | Lock window opens | `auctionId`, `phase: "locked"` | | `auction_cleared` | Auction clears | `auctionId`, `clearingFeeBps` (string or null if no match), `matchedSizeCents` (integer cents) | | `indicative_updated` | Periodically during the open phase | `indicativeFeeBps` (string or null), `matchableSizeCents` (integer cents), `netImbalanceCents` (integer cents) | ### Market channel fields The following fields are present on the `snapshot` event and on most market events. For background on auction phases and clearing, see [How Match works](/circle-match/concepts/how-it-works). | Field | Type | Description | | -------------------- | -------------- | ---------------------------------------------------------------------------- | | `phase` | string | Current auction phase: `"open"`, `"locked"`, or `"settling"` | | `indicativeFeeBps` | string or null | Indicative clearing fee in basis points; null if no indicative match exists | | `matchableSizeCents` | integer | Volume (in cents) that would match at the indicative fee | | `netImbalanceCents` | integer | Net imbalance in cents; negative values indicate burn side exceeds mint side | | `mintTotalCents` | integer | Total mint-side volume in cents | | `burnTotalCents` | integer | Total burn-side volume in cents | | `lockAt` | string | ISO 8601 timestamp when the lock window opens | | `clearAt` | string | ISO 8601 timestamp when the auction clears | | `lastClearResult` | object or null | Result from the last cleared auction; null if no prior auction has cleared | #### `lastClearResult` fields | Field | Type | Description | | ------------------ | -------------- | ------------------------------------------------------- | | `auctionId` | integer | Identifier for the last cleared auction | | `clearingFeeBps` | string or null | Clearing fee in basis points; null if no orders matched | | `matchedSizeCents` | integer | Total matched volume in cents | ## Account channel The account channel is private and scoped to the authenticated entity. It requires a valid ticket. **Subscribe:** ```json theme={null} { "type": "subscribe", "channel": "account" } ``` ### Account channel events | Event type | When sent | Key fields | | -------------------- | ------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------- | | `account_snapshot` | On subscribe | Current open orders, available balance, reserved balance, total balance | | `order_received` | A new order is accepted | `orderId` (UUID), `status: "pending"`, `orderType`, `amount` (integer cents), `feeBps` (string or null), `postFillAction` | | `order_modified` | An order's fee is modified | `orderId`, `feeBps` (string or null) | | `order_canceled` | A single order is cancelled | `orderId`, `status: "cancelled"` | | `order_canceled_all` | A cancel-all request completes | `orderIds` (array of UUIDs), `auctionId` | | `account_cleared` | An auction clears with activity for this account | `fills` (array), `forwardOrders` (array), `feesRebatedCents` (signed integer) | ### `account_cleared` fields | Field | Type | Description | | ------------------ | -------------- | ------------------------------------------------------------------------------------------------------------------------------------------- | | `fills` | array | One fill object per matched order. Each fill contains: `orderId`, `filledAmountCents`, `unfilledAmountCents`, `clearingFeeBps`, `matchedAt` | | `forwardOrders` | array | Orders rolled into the next auction, resulting from a `roll` post-fill action | | `feesRebatedCents` | signed integer | Net rebate or fee for the auction. Positive: net rebate received (mint side). Negative: net fee paid (burn side). Zero: no fills. | ## Reconnection Tickets are single-use and cannot be reused after the connection opens. When a connection drops: 1. Obtain a new ticket using `POST /v1/match/ws/ticket`. 2. Open a new WebSocket connection with the new ticket. 3. Re-send your `subscribe` messages. The server delivers a fresh snapshot on re-subscribe. Events that occurred during the disconnection are not replayed. If the auction cleared while you were disconnected, the `account_cleared` event for that auction is not delivered. Use `GET /v1/match/orders` to reconcile any fills you may have missed.