> ## Documentation Index > Fetch the complete documentation index at: https://docs.hyperprop.com/llms.txt > Use this file to discover all available pages before exploring further. # Close one position on an account > Closes one open position at market, wholly or in part, with the organization API key. The account keeps its status and is not locked out. - **Whole position** (no `quantity`, or the full open size): the contract's working orders on the account are cancelled, the position is closed at market, and its take-profit and stop-loss orders are cancelled after the fill. This is what `POST .../flatten` does, for this one contract. Orders on other contracts are untouched. - **Part of it** (`quantity` below the open size): a reduce-only market order for `quantity`. Working orders stay; take-profit and stop-loss orders keep protecting what remains. The close is an ordinary market order: it fills at the market price with the usual commissions, updates balance and rules like any close, and appears on the real-time stream (`OrderUpdate`, `Fill`, `PositionUpdate`, `AccountUpdate`) and in order history with reason `Admin flatten: — ` (trigger `admin_flatten`). An `ACCOUNT_UPDATED` event (trigger `admin_position_close`) lands on the account's event log and goes to `account.updated` webhooks. It is refused with **409 MARKET_CLOSED** while the contract's market is closed (for example during the daily break, at the weekend or on a holiday); nothing is closed. **Retries:** send an `Idempotency-Key` header to make retries safe; a retry with the same key returns the first answer and never closes twice. A whole-position close repeated without a key answers 404 NO_POSITION once the position is gone. On **504 CLOSE_OUTCOME_UNKNOWN** read the positions before retrying a partial close. Requires **manage** permission on traders. ```bash curl -X POST "https://api.hyperprop.com/platform/v1/organization/trading-accounts/7c9e6679-7425-40de-944b-e07fc1f90ae7/positions/MNQZ6/close" \ -H "X-API-Key: hp_live_your_key_here" \ -H "Content-Type: application/json" \ -H "Idempotency-Key: close-7c9e6679-mnqz6-001" \ -d '{"reason": "Risk review", "quantity": 1}' ``` ## OpenAPI ````yaml https://api.hyperprop.com/platform/openapi.json post /v1/organization/trading-accounts/{accountId}/positions/{contract}/close openapi: 3.0.0 info: title: Hyperprop Platform API version: 1.0.0 description: >- REST API for the Hyperprop Trading Platform — provision evaluation and funded trading accounts, manage traders and plans, react to account lifecycle events via signed webhooks, and reconcile billing. Built for prop firms integrating from their own backend. Authentication, quick start, error handling, idempotency, pagination, custom metadata, webhooks, and the MCP connector are documented at https://docs.hyperprop.com. x-logo: url: https://app.hyperprop.com/logo-icon.svg altText: Hyperprop href: https://hyperprop.com servers: - url: https://api.hyperprop.com/platform description: Production security: [] tags: - name: Trading accounts description: Create, update, and inspect trading accounts. - name: Traders description: Look up and update the traders in your organization. - name: Trading plans description: Define the plans you sell. - name: Trading rules description: Define how accounts are evaluated. - name: Instruments description: >- The contracts your organization's accounts can trade, with their specifications. - name: Lockouts description: Pause and resume trading on an account. - name: Payouts description: Check payout eligibility and record payouts. - name: Purchases description: Purchases recorded for your organization. - name: Time Machine description: Restore accounts to an earlier trading day or instant. - name: Mass credit description: >- Credit back losses across many accounts after an incident, as background jobs you can follow, pause, export and reverse. - name: Webhooks description: Register webhook endpoints and inspect deliveries. - name: Events description: Your organization's event history and real-time event stream. - name: Reconciliation description: Balances, end-of-day snapshots, and fills for reconciliation. - name: Analytics description: Organization performance and plan economics. - name: Billing description: 'Your Hyperprop bill: activity, billing cycles, and forecasts.' - name: Team and roles description: Manage dashboard access for your staff. - name: API keys description: >- Manage your organization's API keys: rotation, read-only keys and IP allowlists. - name: Logs and health description: >- API request logs, the audit log, integration health, and idempotency key recovery. - name: Organization profile description: Your organization's profile and logo. - name: Support description: Open and follow up on support tickets. - name: Partner access description: >- Read a trader's journal as an approved partner app, with the trader's own key. paths: /v1/organization/trading-accounts/{accountId}/positions/{contract}/close: post: tags: - Trading accounts summary: Close one position on an account description: >- Closes one open position at market, wholly or in part, with the organization API key. The account keeps its status and is not locked out. - **Whole position** (no `quantity`, or the full open size): the contract's working orders on the account are cancelled, the position is closed at market, and its take-profit and stop-loss orders are cancelled after the fill. This is what `POST .../flatten` does, for this one contract. Orders on other contracts are untouched. - **Part of it** (`quantity` below the open size): a reduce-only market order for `quantity`. Working orders stay; take-profit and stop-loss orders keep protecting what remains. The close is an ordinary market order: it fills at the market price with the usual commissions, updates balance and rules like any close, and appears on the real-time stream (`OrderUpdate`, `Fill`, `PositionUpdate`, `AccountUpdate`) and in order history with reason `Admin flatten: — ` (trigger `admin_flatten`). An `ACCOUNT_UPDATED` event (trigger `admin_position_close`) lands on the account's event log and goes to `account.updated` webhooks. It is refused with **409 MARKET_CLOSED** while the contract's market is closed (for example during the daily break, at the weekend or on a holiday); nothing is closed. **Retries:** send an `Idempotency-Key` header to make retries safe; a retry with the same key returns the first answer and never closes twice. A whole-position close repeated without a key answers 404 NO_POSITION once the position is gone. On **504 CLOSE_OUTCOME_UNKNOWN** read the positions before retrying a partial close. Requires **manage** permission on traders. ```bash curl -X POST "https://api.hyperprop.com/platform/v1/organization/trading-accounts/7c9e6679-7425-40de-944b-e07fc1f90ae7/positions/MNQZ6/close" \ -H "X-API-Key: hp_live_your_key_here" \ -H "Content-Type: application/json" \ -H "Idempotency-Key: close-7c9e6679-mnqz6-001" \ -d '{"reason": "Risk review", "quantity": 1}' ``` operationId: postV1OrganizationTradingaccountsAccountidPositionsContractClose parameters: - description: Trading account ID x-format: guid: true name: accountId in: path required: true schema: type: string - description: >- Contract symbol of the open position, as on the positions read and the real-time stream name: contract in: path required: true schema: type: string pattern: ^[A-Za-z0-9._-]{1,40}$ requestBody: content: application/json: schema: $ref: '#/components/schemas/Model1481' responses: '200': description: Position closed (wholly or in part) content: '*/*': schema: $ref: '#/components/schemas/Model1487' '400': description: >- Bad Request - Invalid parameter (`VALIDATION_ERROR`) or `quantity` above the open size (`QUANTITY_EXCEEDS_POSITION`) content: '*/*': schema: $ref: '#/components/schemas/Model1489' '401': description: Authentication required content: '*/*': schema: $ref: '#/components/schemas/Model11' '403': description: >- Forbidden - The caller lacks traders:manage (`INSUFFICIENT_PERMISSIONS`) content: '*/*': schema: $ref: '#/components/schemas/Model1490' '404': description: >- Not Found - No account with this ID in your organization (`ACCOUNT_NOT_FOUND`) or no open position in the contract (`NO_POSITION`) content: '*/*': schema: $ref: '#/components/schemas/Model1492' '409': description: >- Conflict - The contract's market is closed (`MARKET_CLOSED`), the engine refused the closing order (`CLOSE_REJECTED`), or a request with this `Idempotency-Key` is still in progress. The position is still open. content: '*/*': schema: $ref: '#/components/schemas/Model1493' '500': description: An unexpected error occurred content: '*/*': schema: $ref: '#/components/schemas/Model6' '502': description: The trading engine could not be reached; nothing was closed content: '*/*': schema: $ref: '#/components/schemas/Model1494' '504': description: >- The trading engine did not answer in time; the position may or may not have been closed. Read the account's positions before retrying. content: '*/*': schema: $ref: '#/components/schemas/Model1495' security: - X-API-Key: [] components: schemas: Model1481: type: object properties: reason: type: string description: >- Why the position is being closed. Recorded on the resulting orders and on the account's event log. example: Risk review minLength: 3 maxLength: 200 x-convert: trim: true quantity: type: integer description: >- How much to close, in the position's units (futures: contracts; perpetuals: units of the contract's `quantityStep`, as `quantity` on the positions read). Omit to close the whole position. example: 1 minimum: 1 maximum: 4294967295 required: - reason Model1487: type: object properties: success: type: boolean example: true data: $ref: '#/components/schemas/Model1486' Model1489: type: object properties: success: type: boolean example: false statusCode: type: number example: 400 error: type: string example: Bad Request message: type: string example: 'Cannot close 3 of MNQZ6: only 2 is open' code: $ref: '#/components/schemas/Model1488' Model11: type: object properties: success: type: boolean description: Always false on errors example: false statusCode: type: number example: 401 error: type: string example: Unauthorized message: type: string example: Authentication required code: type: string description: Machine-readable error code — switch on this, not on message text example: UNAUTHORIZED Model1490: type: object properties: statusCode: type: number example: 403 error: type: string example: Forbidden message: type: string example: Your role does not have write access to "Traders & accounts" code: $ref: '#/components/schemas/code' Model1492: type: object properties: success: type: boolean example: false statusCode: type: number example: 404 error: type: string example: Not Found message: type: string example: No open position in MNQZ6 code: $ref: '#/components/schemas/Model1491' Model1493: type: object properties: success: type: boolean example: false statusCode: type: number example: 409 error: type: string example: Conflict message: type: string example: Market is closed. Trading resumes at session open. code: type: string example: MARKET_CLOSED Model6: type: object properties: success: type: boolean description: Always false on errors example: false statusCode: type: number example: 500 error: type: string example: Internal Server Error message: type: string example: An unexpected error occurred code: type: string description: Machine-readable error code — switch on this, not on message text example: INTERNAL_ERROR Model1494: type: object properties: success: type: boolean description: Always false on errors example: false statusCode: type: number example: 502 error: type: string example: Error message: type: string example: The trading engine could not be reached; nothing was closed code: type: string description: Machine-readable error code — switch on this, not on message text example: ENGINE_UNAVAILABLE Model1495: type: object properties: success: type: boolean description: Always false on errors example: false statusCode: type: number example: 504 error: type: string example: Error message: type: string example: >- The trading engine did not answer in time; the position may or may not have been closed. Read the account's positions before retrying. code: type: string description: Machine-readable error code — switch on this, not on message text example: CLOSE_OUTCOME_UNKNOWN Model1486: type: object properties: accountId: type: string example: 7c9e6679-7425-40de-944b-e07fc1f90ae7 x-format: guid: true accountNumber: type: string example: ACC-50K-000123 contract: type: string example: MNQZ6 side: $ref: '#/components/schemas/Model1482' requestedQuantity: type: integer description: Quantity sent to close example: 1 remainingQuantity: type: integer description: Open size left on the contract after the close; 0 when closed example: 1 closed: type: boolean description: True when no position is left on the contract example: false ordersCancelled: type: integer description: >- Working orders cancelled with a whole-position close (entries, take-profit and stop-loss); 0 for a partial close example: 0 orders: $ref: '#/components/schemas/Model1485' reason: type: string example: 'Admin flatten: API key — Risk review' Model1488: type: string example: QUANTITY_EXCEEDS_POSITION enum: - VALIDATION_ERROR - QUANTITY_EXCEEDS_POSITION code: type: string example: INSUFFICIENT_PERMISSIONS enum: - INSUFFICIENT_PERMISSIONS Model1491: type: string example: NO_POSITION enum: - ACCOUNT_NOT_FOUND - NO_POSITION Model1482: type: string description: Direction of the position before the close example: long enum: - long - short Model1485: type: array description: The closing order(s), with their fill items: $ref: '#/components/schemas/Model1484' Model1484: type: object properties: orderId: type: string x-format: guid: true contract: type: string example: MNQZ6 side: $ref: '#/components/schemas/Model1483' type: type: string example: market quantity: type: integer example: 1 filledQuantity: type: integer example: 1 status: type: string description: >- `filled` when the close executed; `rejected` with `rejectReason` otherwise example: filled avgFillPrice: type: number example: 20010.5 filledAt: type: string example: '2026-10-30T14:41:07.312Z' rejectReason: type: string example: null reason: type: string example: 'Admin flatten: API key — Risk review' Model1483: type: string example: sell enum: - buy - sell securitySchemes: X-API-Key: type: apiKey name: X-API-Key in: header description: >- Organization API key. Format: "hp_live_{key}". Organization admins manage the key in the dashboard. ```` ## Related topics - [Close all positions on an account](https://docs.hyperprop.com/platform-api/trading-accounts/close-all-positions-on-an-account.md) - [Close all positions across accounts](https://docs.hyperprop.com/platform-api/trading-accounts/close-all-positions-across-accounts.md) - [Close all open positions for an account](https://docs.hyperprop.com/trade-api/positions/close-all-open-positions-for-an-account.md) - [Flatten account: close positions and cancel orders](https://docs.hyperprop.com/trade-api/positions/flatten-account:-close-positions-and-cancel-orders.md) - [Set TP/SL at the position level for one (account, contract) pair.](https://docs.hyperprop.com/trade-api/positions/set-tpsl-at-the-position-level-for-one-account-contract-pair.md) This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.