> ## Documentation Index > Fetch the complete documentation index at: https://docs.xo.market/llms.txt > Use this file to discover all available pages before exploring further. # Cancel single order > Cancel a single order via signed `CancelOrder(orderId, marketId)` or via HMAC + `orderID`. ## OpenAPI ````yaml /api-reference/openapi.yaml delete /order openapi: 3.0.3 info: title: XO Orderbook API description: | Public REST surface of the XO CLOB API. XO mainnet chain id is `3223`. The EIP-712 order domain is `XO Market CLOB` with `verifyingContract` set to the [CTF Exchange](/) address. See [Smart accounts](../guides/smart-accounts) for the smart-account identity model and ERC-1271 order signing. Wire conventions: * Prices are trimmed decimal strings (e.g. `"0.5"`, `"0.555"`). * Sizes are decimal-string integers in human shares. * Timestamps in trade and book responses are stringified Unix seconds / milliseconds (the SDK uses `TimestampSeconds` / `TimestampMilliSeconds`). * Token IDs are decimal U256 strings; condition IDs are `0x`-prefixed 32-byte hex. version: 1.0.0 contact: name: XO Market url: https://beta.xo.market servers: - url: https://orderbooks.xo.market description: Mainnet (XO chain id 3223) security: [] tags: - name: Authentication description: >- Create and manage API keys. The L1 ClobAuth EIP-712 flow mints HMAC credentials that authenticate every other private request. - name: Market Data description: >- Public reads for books, prices, midpoints, spreads, last trades, and price history. Also includes server time and per-token configuration. - name: Markets description: >- Discovery for tradable markets, including pagination and SDK-compatible simplified shapes. - name: Trade description: Place, cancel, and inspect orders and trades for the authenticated maker. - name: Account description: Maker balance, allowance, positions, and claimable settled positions. paths: /order: delete: tags: - Trade summary: Cancel single order description: >- Cancel a single order via signed `CancelOrder(orderId, marketId)` or via HMAC + `orderID`. requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CancelOrderRequest' examples: hmac_clob_form: summary: CLOB SDK form (HMAC auth, just `orderID`) value: orderID: '42' eip712_legacy_form: summary: legacy form (EIP-712 cancel signature) value: orderId: 42 marketId: >- 0x39a12d52b63969654926e095ddd96f5c459112714da03edca769aa58173c78fb signature: >- 0xb2c3d4e5f60718293a4b5c6d7e8f90a1b2c3d4e5f60718293a4b5c6d7e8f90a1b2c3d4e5f60718293a4b5c6d7e8f90a1b2c3d4e5f60718293a4b5c6d7e8f90a11c signatureType: 3 signer: '0xCAFE000000000000000000000000000000000A11' responses: '200': description: OK content: application/json: schema: $ref: '#/components/schemas/CancelResponse' examples: canceled_ok: summary: order successfully cancelled value: canceled: - '42' notCanceled: {} already_filled: summary: order was already filled before the cancel arrived value: canceled: [] notCanceled: '42': already filled '401': $ref: '#/components/responses/Error401' '404': $ref: '#/components/responses/Error404' x-codeSamples: - lang: Rust label: xo-orderbook-client-rs source: > // Requires an authenticated client (see POST /order for setup). let resp = client .cancel_order("0x0011223344556677889900aabbccddeeff00112233445566778899aabbccddee") .await?; println!("canceled: {:?}, not canceled: {:?}", resp.canceled, resp.not_canceled); components: schemas: CancelOrderRequest: type: object required: - orderId - marketId - signature - signatureType properties: orderId: type: integer format: int64 marketId: type: string signature: type: string description: EIP-712 sig over CancelOrder(orderId, marketId) signatureType: type: integer enum: - 0 - 3 description: 0 = EOA, 3 = EIP-1271 smart wallet signer: type: string description: Required when signatureType = 3 CancelResponse: type: object description: | Wire shape uses **camelCase** (`canceled` / `notCanceled`) per the CLOB SDK contract. American spelling — one `l` (NOT `cancelled`). Shared by `DELETE /order`, `DELETE /orders`, `DELETE /cancel-all`, `DELETE /cancel-market-orders`. required: - canceled - notCanceled properties: canceled: type: array items: type: string description: Order ids that were successfully cancelled, decimal strings. notCanceled: type: object additionalProperties: type: string description: | Map of ` → ` for orders that could not be cancelled. Common reasons: `"already filled"`, `"not found"`, `"not owner"`. ErrorResponse: type: object required: - error properties: error: type: string responses: Error401: description: | Authentication failure. L1 ClobAuth (wallet) or L2 HMAC (API key) headers were missing, malformed, expired, or did not match the requested resource. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: l1_required: summary: L1 ClobAuth headers missing value: error: L1 ClobAuth headers required l2_required: summary: HMAC credentials missing value: error: HMAC L2 credentials required address_mismatch: summary: L1-recovered address does not match request value: error: L1 auth address does not match request address Error404: description: | Resource not found. The message embeds the requested identifier verbatim (`market not found: 0x…`, `trade not found: 0x…`, `no API key found for address 0x…`). Read endpoints that fail token lookup return the canonical CLOB string `"No orderbook exists for the requested token id"`. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: market_not_found: summary: unknown condition_id value: error: >- market not found: 0x0000000000000000000000000000000000000000000000000000000000000000 no_orderbook: summary: unknown token_id on a read endpoint value: error: No orderbook exists for the requested token id trade_not_found: summary: unknown trade id value: error: >- trade not found: 0x0000000000000000000000000000000000000000000000000000000000000000 api_key_not_found: summary: derive-api-key called for an address with no key value: error: >- no API key found for address 0xCAFE000000000000000000000000000000000A11 ````