> ## Documentation Index > Fetch the complete documentation index at: https://docs.kalshi.com/llms.txt > Use this file to discover all available pages before exploring further. # WebSocket Connection > Main WebSocket connection endpoint. Authentication is required during the WebSocket handshake. ## AsyncAPI ````yaml perps_asyncapi.yaml root id: root title: WebSocket Connection description: | Main WebSocket connection endpoint. Authentication is required during the WebSocket handshake. servers: - id: production protocol: wss host: external-api-margin-ws.kalshi.com bindings: [] variables: [] - id: demo protocol: wss host: external-api-margin-ws.demo.kalshi.co bindings: [] variables: [] address: / parameters: [] bindings: - protocol: ws version: latest value: method: GET schemaProperties: - name: method type: string description: GET required: false operations: - &ref_6 id: sendSubscribe title: Subscribe to Channels type: receive messages: - &ref_17 id: subscribeCommand contentType: application/json payload: - name: Subscribe Command description: Subscribe to one or more margin channels type: object properties: - name: id type: integer description: Unique ID of a command within a WebSocket session required: true - name: cmd type: string description: subscribe required: true - name: params type: object required: true properties: - name: channels type: array required: true properties: - name: item type: string enumValues: - orderbook_delta - ticker - trade - fill - user_orders - order_group_updates required: false - name: market_ticker type: string required: false - name: market_tickers type: array required: false properties: - name: item type: string description: Unique market identifier required: false - name: send_initial_snapshot type: boolean description: Sends an initial snapshot for ticker subscriptions. required: false - name: skip_ticker_ack type: boolean required: false headers: [] jsonPayloadSchema: type: object required: - id - cmd - params properties: id: &ref_0 type: integer minimum: 0 description: Unique ID of a command within a WebSocket session x-parser-schema-id: commandId cmd: type: string const: subscribe x-parser-schema-id: params: type: object required: - channels properties: channels: type: array minItems: 1 items: type: string enum: - orderbook_delta - ticker - trade - fill - user_orders - order_group_updates x-parser-schema-id: x-parser-schema-id: market_ticker: type: string x-parser-schema-id: market_tickers: type: array items: &ref_3 type: string description: Unique market identifier x-parser-schema-id: marketTicker minItems: 1 x-parser-schema-id: send_initial_snapshot: type: boolean description: Sends an initial snapshot for ticker subscriptions. default: false x-parser-schema-id: skip_ticker_ack: type: boolean default: false x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: subscribeCommandPayload title: Subscribe Command description: Subscribe to one or more margin channels example: No examples found bindings: [] extensions: - id: x-parser-unique-object-id value: subscribeCommand bindings: [] extensions: &ref_1 - id: x-parser-unique-object-id value: root - &ref_7 id: sendUnsubscribe title: Unsubscribe from Channels type: receive messages: - &ref_18 id: unsubscribeCommand contentType: application/json payload: - name: Unsubscribe Command description: Cancel one or more subscriptions type: object properties: - name: id type: integer description: Unique ID of a command within a WebSocket session required: true - name: cmd type: string description: unsubscribe required: true - name: params type: object required: true properties: - name: sids type: array required: true properties: - name: item type: integer description: Server-generated subscription identifier required: false headers: [] jsonPayloadSchema: type: object required: - id - cmd - params properties: id: *ref_0 cmd: type: string const: unsubscribe x-parser-schema-id: params: type: object required: - sids properties: sids: type: array items: &ref_2 type: integer minimum: 1 description: Server-generated subscription identifier x-parser-schema-id: subscriptionId minItems: 1 x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: unsubscribeCommandPayload title: Unsubscribe Command description: Cancel one or more subscriptions example: No examples found bindings: [] extensions: - id: x-parser-unique-object-id value: unsubscribeCommand bindings: [] extensions: *ref_1 - &ref_8 id: sendListSubscriptions title: List Subscriptions type: receive messages: - &ref_19 id: listSubscriptionsCommand contentType: application/json payload: - name: List Subscriptions Command description: List all active subscriptions type: object properties: - name: id type: integer description: Unique ID of a command within a WebSocket session required: true - name: cmd type: string description: list_subscriptions required: true headers: [] jsonPayloadSchema: type: object required: - id - cmd properties: id: *ref_0 cmd: type: string const: list_subscriptions x-parser-schema-id: x-parser-schema-id: listSubscriptionsCommandPayload title: List Subscriptions Command description: List all active subscriptions example: |- { "id": 123, "cmd": "" } bindings: [] extensions: - id: x-parser-unique-object-id value: listSubscriptionsCommand bindings: [] extensions: *ref_1 - &ref_9 id: sendUpdateSubscription title: Update Subscription - Add Markets type: receive messages: - &ref_20 id: updateSubscriptionCommand contentType: application/json payload: - name: Update Subscription - Add Markets description: Add markets to an existing subscription type: object properties: - name: id type: integer description: Unique ID of a command within a WebSocket session required: true - name: cmd type: string description: update_subscription required: true - name: params type: object required: true properties: - name: sid type: integer description: Server-generated subscription identifier required: false - name: sids type: array required: false properties: - name: item type: integer description: Server-generated subscription identifier required: false - name: market_ticker type: string required: false - name: market_tickers type: array required: false properties: - name: item type: string description: Unique market identifier required: false - name: send_initial_snapshot type: boolean description: >- Sends an initial snapshot for newly added ticker subscriptions. required: false - name: action type: string enumValues: - add_markets - delete_markets required: true headers: [] jsonPayloadSchema: &ref_4 type: object required: - id - cmd - params properties: id: *ref_0 cmd: type: string const: update_subscription x-parser-schema-id: params: type: object required: - action properties: sid: *ref_2 sids: type: array items: *ref_2 minItems: 1 maxItems: 1 x-parser-schema-id: market_ticker: type: string x-parser-schema-id: market_tickers: type: array items: *ref_3 minItems: 1 x-parser-schema-id: send_initial_snapshot: type: boolean description: >- Sends an initial snapshot for newly added ticker subscriptions. default: false x-parser-schema-id: action: type: string enum: - add_markets - delete_markets x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: updateSubscriptionCommandPayload title: Update Subscription - Add Markets description: Add markets to an existing subscription example: No examples found bindings: [] extensions: - id: x-parser-unique-object-id value: updateSubscriptionCommand bindings: [] extensions: *ref_1 - &ref_10 id: sendUpdateSubscriptionDelete title: Update Subscription - Delete Markets type: receive messages: - &ref_21 id: updateSubscriptionDeleteCommand contentType: application/json payload: - name: Update Subscription - Delete Markets description: Remove markets from an existing subscription type: object properties: - name: id type: integer description: Unique ID of a command within a WebSocket session required: true - name: cmd type: string description: update_subscription required: true - name: params type: object required: true properties: - name: sid type: integer description: Server-generated subscription identifier required: false - name: sids type: array required: false properties: - name: item type: integer description: Server-generated subscription identifier required: false - name: market_ticker type: string required: false - name: market_tickers type: array required: false properties: - name: item type: string description: Unique market identifier required: false - name: send_initial_snapshot type: boolean description: >- Sends an initial snapshot for newly added ticker subscriptions. required: false - name: action type: string enumValues: - add_markets - delete_markets required: true headers: [] jsonPayloadSchema: *ref_4 title: Update Subscription - Delete Markets description: Remove markets from an existing subscription example: No examples found bindings: [] extensions: - id: x-parser-unique-object-id value: updateSubscriptionDeleteCommand bindings: [] extensions: *ref_1 - &ref_11 id: sendUpdateSubscriptionSingleSid title: Update Subscription - Single SID type: receive messages: - &ref_22 id: updateSubscriptionSingleSidCommand contentType: application/json payload: - name: Update Subscription - Single SID description: Update a subscription using `sid` rather than `sids` type: object properties: - name: id type: integer description: Unique ID of a command within a WebSocket session required: true - name: cmd type: string description: update_subscription required: true - name: params type: object required: true properties: - name: sid type: integer description: Server-generated subscription identifier required: false - name: sids type: array required: false properties: - name: item type: integer description: Server-generated subscription identifier required: false - name: market_ticker type: string required: false - name: market_tickers type: array required: false properties: - name: item type: string description: Unique market identifier required: false - name: send_initial_snapshot type: boolean description: >- Sends an initial snapshot for newly added ticker subscriptions. required: false - name: action type: string enumValues: - add_markets - delete_markets required: true headers: [] jsonPayloadSchema: *ref_4 title: Update Subscription - Single SID description: Update a subscription using `sid` rather than `sids` example: No examples found bindings: [] extensions: - id: x-parser-unique-object-id value: updateSubscriptionSingleSidCommand bindings: [] extensions: *ref_1 - &ref_12 id: receiveSubscribed title: Subscription Confirmed type: send messages: - &ref_23 id: subscribedResponse contentType: application/json payload: - name: Subscribed Response description: Confirmation that subscription was successful type: object properties: - name: id type: integer description: Unique ID of a command within a WebSocket session required: false - name: type type: string description: subscribed required: true - name: msg type: object required: true properties: - name: channel type: string required: true - name: sid type: integer description: Server-generated subscription identifier required: true headers: [] jsonPayloadSchema: type: object required: - type - msg properties: id: *ref_0 type: type: string const: subscribed x-parser-schema-id: msg: type: object required: - channel - sid properties: channel: type: string x-parser-schema-id: sid: *ref_2 x-parser-schema-id: x-parser-schema-id: subscribedResponsePayload title: Subscribed Response description: Confirmation that subscription was successful example: |- { "id": 123, "type": "", "msg": { "channel": "", "sid": 123 } } bindings: [] extensions: - id: x-parser-unique-object-id value: subscribedResponse bindings: [] extensions: *ref_1 - &ref_13 id: receiveUnsubscribed title: Unsubscription Confirmed type: send messages: - &ref_24 id: unsubscribedResponse contentType: application/json payload: - name: Unsubscribed Response description: Confirmation that unsubscription was successful type: object properties: - name: id type: integer description: Unique ID of a command within a WebSocket session required: false - name: sid type: integer description: Server-generated subscription identifier required: true - name: seq type: integer description: Sequence number used for snapshot/delta consistency required: true - name: type type: string description: unsubscribed required: true headers: [] jsonPayloadSchema: type: object required: - sid - seq - type properties: id: *ref_0 sid: *ref_2 seq: &ref_5 type: integer minimum: 1 description: Sequence number used for snapshot/delta consistency x-parser-schema-id: sequenceNumber type: type: string const: unsubscribed x-parser-schema-id: x-parser-schema-id: unsubscribedResponsePayload title: Unsubscribed Response description: Confirmation that unsubscription was successful example: |- { "id": 123, "sid": 123, "seq": 123, "type": "" } bindings: [] extensions: - id: x-parser-unique-object-id value: unsubscribedResponse bindings: [] extensions: *ref_1 - &ref_14 id: receiveOk title: Update Confirmed type: send messages: - &ref_25 id: okResponse contentType: application/json payload: - name: OK Response description: Successful update operation response type: object properties: - name: id type: integer description: Unique ID of a command within a WebSocket session required: false - name: sid type: integer description: Server-generated subscription identifier required: false - name: seq type: integer description: Sequence number used for snapshot/delta consistency required: false - name: type type: string description: ok required: true - name: msg type: object required: false properties: - name: market_tickers type: array required: false properties: - name: item type: string description: Unique market identifier required: false headers: [] jsonPayloadSchema: type: object required: - type properties: id: *ref_0 sid: *ref_2 seq: *ref_5 type: type: string const: ok x-parser-schema-id: msg: type: object properties: market_tickers: type: array items: *ref_3 x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: okResponsePayload title: OK Response description: Successful update operation response example: No examples found bindings: [] extensions: - id: x-parser-unique-object-id value: okResponse bindings: [] extensions: *ref_1 - &ref_15 id: receiveListSubscriptions title: List Subscriptions Response type: send messages: - &ref_26 id: listSubscriptionsResponse contentType: application/json payload: - name: List Subscriptions Response description: Response containing all active subscriptions type: object properties: - name: id type: integer description: Unique ID of a command within a WebSocket session required: true - name: type type: string description: ok required: true - name: msg type: array required: true properties: - name: channel type: string required: true - name: sid type: integer description: Server-generated subscription identifier required: true headers: [] jsonPayloadSchema: type: object required: - id - type - msg properties: id: *ref_0 type: type: string const: ok x-parser-schema-id: msg: type: array items: type: object required: - channel - sid properties: channel: type: string x-parser-schema-id: sid: *ref_2 x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: listSubscriptionsResponsePayload title: List Subscriptions Response description: Response containing all active subscriptions example: |- { "id": 123, "type": "", "msg": { "channel": "", "sid": 123 } } bindings: [] extensions: - id: x-parser-unique-object-id value: listSubscriptionsResponse bindings: [] extensions: *ref_1 - &ref_16 id: receiveError title: Error Response type: send messages: - &ref_27 id: errorResponse contentType: application/json payload: - name: Error Response description: Error response for failed operations type: object properties: - name: id type: integer description: Unique ID of a command within a WebSocket session required: false - name: type type: string description: error required: true - name: msg type: object required: true properties: - name: code type: integer required: true - name: msg type: string required: true - name: market_ticker type: string required: false headers: [] jsonPayloadSchema: type: object required: - type - msg properties: id: *ref_0 type: type: string const: error x-parser-schema-id: msg: type: object required: - code - msg properties: code: type: integer minimum: 1 maximum: 18 x-parser-schema-id: msg: type: string x-parser-schema-id: market_ticker: type: string x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: errorResponsePayload title: Error Response description: Error response for failed operations example: |- { "id": 123, "type": "", "msg": { "code": 123, "msg": "", "market_ticker": "" } } bindings: [] extensions: - id: x-parser-unique-object-id value: errorResponse bindings: [] extensions: *ref_1 sendOperations: - *ref_6 - *ref_7 - *ref_8 - *ref_9 - *ref_10 - *ref_11 receiveOperations: - *ref_12 - *ref_13 - *ref_14 - *ref_15 - *ref_16 sendMessages: - *ref_17 - *ref_18 - *ref_19 - *ref_20 - *ref_21 - *ref_22 receiveMessages: - *ref_23 - *ref_24 - *ref_25 - *ref_26 - *ref_27 extensions: - id: x-parser-unique-object-id value: root securitySchemes: - id: apiKey name: apiKey type: apiKey description: API key authentication required for margin WebSocket connections. in: user extensions: [] ````