> ## Documentation Index > Fetch the complete documentation index at: https://docs.novig.com/llms.txt > Use this file to discover all available pages before exploring further. # Cancel order > Cancel a specific order by its unique identifier. The order must belong to the trader associated with the API key. This operation is idempotent, but does not make guarantees about reaching the matching engine before the order is filled. To reliably ensure that an order has been cancelled, consume messages from the matching tape to reconstruct the order book and other stateful structures. > **Note:** A successful response indicates that the cancellation request was sent to the queue, but does **not** guarantee that the order will be cancelled. **Rate limit:** 1,000 requests per second. ## OpenAPI ````yaml /api-reference/spec-files/openapi31.json delete /nbx/v2/emm/orders/{orderId} openapi: 3.1.0 info: title: NBX API description: >+ ## API Overview The NBX API is designed with a tri-interface architecture: - **REST API** - **URL:** `https://api.novig.us/nbx/v2` - **Constraints:** - **Rate limits:** - Order placement (single and batch): 20 requests per second - Order cancellation: 1,000 requests per second - Kill switch: 1 request per 30 seconds - Data retrieval: 100 requests per second - User history (`/fills`, `/orders`, `/transactions`): 16 requests/second burst, 256 requests/minute sustained - **Timeout:** 5 seconds - **Features:** - Place, cancel, and query orders. - Retrieve market data and positions. - Manage account settings and balances. - **Best Practices:** - Use appropriate HTTP methods. - Include `Authorization` and `Content-Type` headers. - Implement exponential backoff for handling rate limits and robust error handling. - **WebSocket API** - **URL:** `wss://api.novig.us/tape` - **Constraints:** - **Rate limit:** 10 messages per minute - **Timeout:** 300 seconds without heartbeat - **Features:** - Real-time order book ticks. - Real-time market lifecycle updates. - Private fill and cancel notifications. - Heartbeat mechanism to ensure connection health. - **Best Practices:** - Implement reconnection logic with exponential backoff. - Process messages sequentially to maintain order book integrity. - Appropriately handle various event types. - Subscribe to specific market events or to the global tape. - **GraphQL API** - **URL:** `https://gql.novig.us/v1/graphql` - **Constraints:** - **Rate limit:** 650 requests per minute - **Timeout:** 2 seconds - **Features:** - Interactive Explorer available via [**Hoppscotch GraphQL Sandbox**](https://hoppscotch.io/graphql) - Flexible querying of market data and prices with tailored filters. - Access historical data and statistics. - Role-based access control with baseline lurker permissions. - **Best Practices:** - Use GraphQL for historical analysis and non-time-critical queries. - Opt for the WebSocket API for real-time data needs. ## Authentication The NBX API uses [**OAuth 2.0 Client Credentials**](https://auth0.com/docs/get-started/authentication-and-authorization-flow/client-credentials-flow) with JSON Web Tokens (JWT). 1. **Obtain Credentials:** Request your client ID and secret from Novig. 2. **Request an Access Token:** Send a POST request to the OAuth endpoint. For example: ```bash curl --request POST --url https://auth.novig.us/oauth/token --header "Content-Type: application/json" --data '{ "audience" : "https://api.novig.us", "grant_type" : "client_credentials", "client_id" : "YOUR_CLIENT_ID", "client_secret" : "YOUR_CLIENT_SECRET" }' ``` 3. **Use the Token:** Include the token in your requests by setting the HTTP header: ```bash Authorization: Bearer YOUR_ACCESS_TOKEN ``` > **Note:** For integration in the QA environment, you'll need to use different endpoints: > - **Issuer:** `https://auth-qa.novig.us` > - **Audience:** `https://api-qa.novig.us` > - **API Base URL:** `https://api-qa.novig.us` version: 0.0.44 contact: name: Contact url: https://novig.us email: tech@novig.us servers: - url: https://api.novig.us description: Production - url: https://api-qa.novig.us description: QA security: [] tags: - name: Orders description: Endpoints for managing orders and trades - name: Markets description: Endpoints for accessing market data and order books - name: Events description: Endpoints for discovering events and fetching event-related data - name: Account description: Endpoints for managing account settings and balances - name: Positions description: Endpoints for accessing positions and fills - name: WebSockets description: Channels for real-time market data and order updates - name: GraphQL description: GraphQL API for querying market data and prices paths: /nbx/v2/emm/orders/{orderId}: delete: tags: - Orders summary: Cancel order description: >- Cancel a specific order by its unique identifier. The order must belong to the trader associated with the API key. This operation is idempotent, but does not make guarantees about reaching the matching engine before the order is filled. To reliably ensure that an order has been cancelled, consume messages from the matching tape to reconstruct the order book and other stateful structures. > **Note:** A successful response indicates that the cancellation request was sent to the queue, but does **not** guarantee that the order will be cancelled. **Rate limit:** 1,000 requests per second. operationId: cancelSingleOrder parameters: - name: orderId required: true in: path description: The server-generated UUID of the order to be cancelled schema: type: string responses: '200': description: Order cancelled successfully. content: application/json: schema: $ref: '#/components/schemas/OrderResponseDto' '400': description: Bad request components: schemas: OrderResponseDto: type: object properties: id: type: string description: The unique identifier of the order example: 123e4567-e89b-12d3-a456-426614174002 outcomeId: type: string description: The ID of the outcome associated with this order example: 123e4567-e89b-12d3-a456-426614174000 marketId: type: string description: The ID of the market associated with this order example: 123e4567-e89b-12d3-a456-426614174003 price: type: number description: The limit price at which the order is placed example: 0.125 qty: type: number description: >- The remaining quantity of the order, denominated in Minimum Currency Units example: 4200 originalQty: type: number description: >- The original quantity of the order, denominated in Minimum Currency Units example: 4200 currency: type: string description: The currency in which the order is denominated example: COIN timestamp: type: string description: The timestamp when the order was placed example: '2023-10-05T12:00:00Z' status: type: string description: The current status of the order example: FILLED flags: type: string description: The trader-specified metadata associated with the order example: ABC12345 ````