> ## 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_7 id: sendSubscribe title: Subscribe to Channels type: receive messages: - &ref_18 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 the command request. Generated by the client and should be unique within a WS session. The simplest way to use it would be to start from 1 and then increment the value for every new command sent to the server. If the id is set to 0, the server treats it the same way as if there was no id. 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 - corporate_actions 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 description: > Unique ID of the command request. Generated by the client and should be unique within a WS session. The simplest way to use it would be to start from 1 and then increment the value for every new command sent to the server. If the id is set to 0, the server treats it the same way as if there was no id. minimum: 0 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 - corporate_actions 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_8 id: sendUnsubscribe title: Unsubscribe from Channels type: receive messages: - &ref_19 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 the command request. Generated by the client and should be unique within a WS session. The simplest way to use it would be to start from 1 and then increment the value for every new command sent to the server. If the id is set to 0, the server treats it the same way as if there was no id. required: true - name: cmd type: string description: unsubscribe required: true - name: params type: object required: true properties: - name: sids type: array description: List of subscription IDs to cancel required: true properties: - name: item type: integer description: >- Server-generated subscription identifier (sid) used to identify the channel 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 description: List of subscription IDs to cancel items: &ref_2 type: integer description: >- Server-generated subscription identifier (sid) used to identify the channel minimum: 1 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_9 id: sendListSubscriptions title: List Subscriptions type: receive messages: - &ref_20 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 the command request. Generated by the client and should be unique within a WS session. The simplest way to use it would be to start from 1 and then increment the value for every new command sent to the server. If the id is set to 0, the server treats it the same way as if there was no id. 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_10 id: sendUpdateSubscription title: Update Subscription - Add Markets type: receive messages: - &ref_21 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 the command request. Generated by the client and should be unique within a WS session. The simplest way to use it would be to start from 1 and then increment the value for every new command sent to the server. If the id is set to 0, the server treats it the same way as if there was no id. 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 (sid) used to identify the channel required: false - name: sids type: array required: false properties: - name: item type: integer description: >- Server-generated subscription identifier (sid) used to identify the channel 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 - get_snapshot 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 - get_snapshot 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_11 id: sendUpdateSubscriptionDelete title: Update Subscription - Delete Markets type: receive messages: - &ref_22 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 the command request. Generated by the client and should be unique within a WS session. The simplest way to use it would be to start from 1 and then increment the value for every new command sent to the server. If the id is set to 0, the server treats it the same way as if there was no id. 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 (sid) used to identify the channel required: false - name: sids type: array required: false properties: - name: item type: integer description: >- Server-generated subscription identifier (sid) used to identify the channel 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 - get_snapshot 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_12 id: sendUpdateSubscriptionSingleSid title: Update Subscription - Single SID type: receive messages: - &ref_23 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 the command request. Generated by the client and should be unique within a WS session. The simplest way to use it would be to start from 1 and then increment the value for every new command sent to the server. If the id is set to 0, the server treats it the same way as if there was no id. 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 (sid) used to identify the channel required: false - name: sids type: array required: false properties: - name: item type: integer description: >- Server-generated subscription identifier (sid) used to identify the channel 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 - get_snapshot 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_13 id: receiveSubscribed title: Subscription Confirmed type: send messages: - &ref_24 id: subscribedResponse contentType: application/json payload: - name: Subscribed Response description: Confirmation that subscription was successful type: object properties: - name: type type: string description: subscribed required: true - name: id type: integer description: > Unique ID of the command request. Generated by the client and should be unique within a WS session. The simplest way to use it would be to start from 1 and then increment the value for every new command sent to the server. If the id is set to 0, the server treats it the same way as if there was no id. required: false - name: msg type: object required: true properties: - name: channel type: string required: true - name: sid type: integer description: >- Server-generated subscription identifier (sid) used to identify the channel required: true - name: sending_ts_ms type: integer description: >- Unix timestamp in milliseconds when Kalshi queued this message at the network layer. required: false headers: [] jsonPayloadSchema: type: object required: - type - msg properties: type: type: string const: subscribed x-parser-schema-id: id: *ref_0 msg: type: object required: - channel - sid properties: channel: type: string x-parser-schema-id: sid: *ref_2 x-parser-schema-id: sending_ts_ms: &ref_5 type: integer format: int64 description: >- Unix timestamp in milliseconds when Kalshi queued this message at the network layer. x-parser-schema-id: sendingTimestampMs x-parser-schema-id: subscribedResponsePayload title: Subscribed Response description: Confirmation that subscription was successful example: |- { "type": "", "id": 123, "msg": { "channel": "", "sid": 123 }, "sending_ts_ms": 123 } bindings: [] extensions: - id: x-parser-unique-object-id value: subscribedResponse bindings: [] extensions: *ref_1 - &ref_14 id: receiveUnsubscribed title: Unsubscription Confirmed type: send messages: - &ref_25 id: unsubscribedResponse contentType: application/json payload: - name: Unsubscribed Response description: Confirmation that unsubscription was successful type: object properties: - name: type type: string description: unsubscribed required: true - name: id type: integer description: > Unique ID of the command request. Generated by the client and should be unique within a WS session. The simplest way to use it would be to start from 1 and then increment the value for every new command sent to the server. If the id is set to 0, the server treats it the same way as if there was no id. required: false - name: sid type: integer description: >- Server-generated subscription identifier (sid) used to identify the channel required: true - name: seq type: integer description: >- Sequential number that should be checked if you want to guarantee you received all the messages. Used for snapshot/delta consistency required: true - name: sending_ts_ms type: integer description: >- Unix timestamp in milliseconds when Kalshi queued this message at the network layer. required: false headers: [] jsonPayloadSchema: type: object required: - sid - seq - type properties: type: type: string const: unsubscribed x-parser-schema-id: id: *ref_0 sid: *ref_2 seq: &ref_6 type: integer description: >- Sequential number that should be checked if you want to guarantee you received all the messages. Used for snapshot/delta consistency minimum: 1 x-parser-schema-id: sequenceNumber sending_ts_ms: *ref_5 x-parser-schema-id: unsubscribedResponsePayload title: Unsubscribed Response description: Confirmation that unsubscription was successful example: |- { "type": "", "id": 123, "sid": 123, "seq": 123, "sending_ts_ms": 123 } bindings: [] extensions: - id: x-parser-unique-object-id value: unsubscribedResponse bindings: [] extensions: *ref_1 - &ref_15 id: receiveOk title: Update Confirmed type: send messages: - &ref_26 id: okResponse contentType: application/json payload: - name: OK Response description: Successful update operation response type: object properties: - name: type type: string description: ok required: true - name: id type: integer description: > Unique ID of the command request. Generated by the client and should be unique within a WS session. The simplest way to use it would be to start from 1 and then increment the value for every new command sent to the server. If the id is set to 0, the server treats it the same way as if there was no id. required: false - name: sid type: integer description: >- Server-generated subscription identifier (sid) used to identify the channel required: false - name: seq type: integer description: >- Sequential number that should be checked if you want to guarantee you received all the messages. Used for snapshot/delta consistency required: false - name: msg type: object required: false properties: - name: market_tickers type: array description: Full list of market tickers after update required: false properties: - name: item type: string description: Unique market identifier required: false - name: market_ids type: array description: Full list of market IDs after update required: false properties: - name: item type: string description: Unique market UUID required: false - name: sending_ts_ms type: integer description: >- Unix timestamp in milliseconds when Kalshi queued this message at the network layer. required: false headers: [] jsonPayloadSchema: type: object required: - type properties: type: type: string const: ok x-parser-schema-id: id: *ref_0 sid: *ref_2 seq: *ref_6 msg: type: object properties: market_tickers: type: array description: Full list of market tickers after update items: *ref_3 x-parser-schema-id: market_ids: type: array description: Full list of market IDs after update items: type: string description: Unique market UUID format: uuid x-parser-schema-id: marketId x-parser-schema-id: x-parser-schema-id: sending_ts_ms: *ref_5 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_16 id: receiveListSubscriptions title: List Subscriptions Response type: send messages: - &ref_27 id: listSubscriptionsResponse contentType: application/json payload: - name: List Subscriptions Response description: Response containing all active subscriptions type: object properties: - name: type type: string description: ok required: true - name: id type: integer description: > Unique ID of the command request. Generated by the client and should be unique within a WS session. The simplest way to use it would be to start from 1 and then increment the value for every new command sent to the server. If the id is set to 0, the server treats it the same way as if there was no id. required: false - name: msg type: array description: List of active subscriptions required: true properties: - name: channel type: string description: Name of the subscribed channel required: true - name: sid type: integer description: >- Server-generated subscription identifier (sid) used to identify the channel required: true - name: sending_ts_ms type: integer description: >- Unix timestamp in milliseconds when Kalshi queued this message at the network layer. required: false headers: [] jsonPayloadSchema: type: object required: - type - msg properties: type: type: string const: ok x-parser-schema-id: id: *ref_0 msg: type: array description: List of active subscriptions items: type: object required: - channel - sid properties: channel: type: string description: Name of the subscribed channel x-parser-schema-id: sid: *ref_2 x-parser-schema-id: x-parser-schema-id: sending_ts_ms: *ref_5 x-parser-schema-id: listSubscriptionsResponsePayload title: List Subscriptions Response description: Response containing all active subscriptions example: |- { "type": "", "id": 123, "msg": { "channel": "", "sid": 123 }, "sending_ts_ms": 123 } bindings: [] extensions: - id: x-parser-unique-object-id value: listSubscriptionsResponse bindings: [] extensions: *ref_1 - &ref_17 id: receiveError title: Error Response type: send messages: - &ref_28 id: errorResponse contentType: application/json payload: - name: Error Response description: Error response for failed operations type: object properties: - name: type type: string description: error required: true - name: id type: integer description: > Unique ID of the command request. Generated by the client and should be unique within a WS session. The simplest way to use it would be to start from 1 and then increment the value for every new command sent to the server. If the id is set to 0, the server treats it the same way as if there was no id. required: false - name: sid type: integer description: >- Server-generated subscription identifier (sid) used to identify the channel required: false - name: seq type: integer description: >- Sequential number that should be checked if you want to guarantee you received all the messages. Used for snapshot/delta consistency required: false - name: msg type: object required: true properties: - name: code type: integer description: > Error codes the Margin WebSocket endpoint can emit. Numbering is shared with the Predictions WebSocket API, so the list is not contiguous. Codes 23, 24, and 28 are used only on channels outside the public Margin surface. Codes 6, 16, and 17 are retired; the service no longer emits them and their numbers stay reserved. enumValues: - 1 - 2 - 3 - 4 - 5 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 18 - 23 - 24 - 25 - 26 - 27 - 28 required: true - name: msg type: string required: true - name: market_ticker type: string description: Optional market ticker associated with the error required: false - name: market_tickers type: array description: Optional market tickers associated with the error required: false properties: - name: item type: string required: false - name: sending_ts_ms type: integer description: >- Unix timestamp in milliseconds when Kalshi queued this message at the network layer. required: false headers: [] jsonPayloadSchema: type: object required: - type - msg properties: type: type: string const: error x-parser-schema-id: id: *ref_0 sid: *ref_2 seq: *ref_6 msg: type: object required: - code - msg properties: code: type: integer description: > Error codes the Margin WebSocket endpoint can emit. Numbering is shared with the Predictions WebSocket API, so the list is not contiguous. Codes 23, 24, and 28 are used only on channels outside the public Margin surface. Codes 6, 16, and 17 are retired; the service no longer emits them and their numbers stay reserved. enum: - 1 - 2 - 3 - 4 - 5 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 18 - 23 - 24 - 25 - 26 - 27 - 28 x-parser-schema-id: msg: type: string x-parser-schema-id: market_ticker: type: string description: Optional market ticker associated with the error x-parser-schema-id: market_tickers: type: array description: Optional market tickers associated with the error items: type: string x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: sending_ts_ms: *ref_5 x-parser-schema-id: errorResponsePayload title: Error Response description: Error response for failed operations example: No examples found bindings: [] extensions: - id: x-parser-unique-object-id value: errorResponse bindings: [] extensions: *ref_1 sendOperations: - *ref_7 - *ref_8 - *ref_9 - *ref_10 - *ref_11 - *ref_12 receiveOperations: - *ref_13 - *ref_14 - *ref_15 - *ref_16 - *ref_17 sendMessages: - *ref_18 - *ref_19 - *ref_20 - *ref_21 - *ref_22 - *ref_23 receiveMessages: - *ref_24 - *ref_25 - *ref_26 - *ref_27 - *ref_28 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: [] ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.