> ## Documentation Index > Fetch the complete documentation index at: https://docs.usecobalt.com/llms.txt > Use this file to discover all available pages before exploring further. # Create Payment > Posts a patient payment back to the provider's EMR ledger. Posting payments is an asynchronous operation. The endpoint validates your request, queues the payment, and returns immediately with a `payment_id` and `job_id`. The payment is posted to the EMR by a background worker, and a webhook event is sent to your registered endpoint upon completion. ### Request Parameters #### Required Fields * **patient\_mrn** (string, required): Medical Record Number (MRN) of the patient the payment belongs to. * **payment\_method** (string, required): Name of the payment method as configured in the EMR (e.g. `"Card"`). The worker resolves this name to the EMR's internal payment method id at post time. * **reference\_number** (string, required): Your reference for the payment (e.g. a transaction or receipt number). Reference numbers may be reused across payments — they are not used as a uniqueness key. * **location** (string, required): Identifier of the EMR location/facility the payment is posted against. * **amount** (number, required): Payment amount. Must be a positive number. #### Optional Fields * **notes** (string, optional): Free-text note recorded with the payment in the EMR. * **deposit\_date** (string, optional): Deposit date in `YYYY-MM-DD` format. Defaults to today if omitted. ### Example Request ```bash theme={null} curl -X POST https://api.usecobalt.com/v1/payments \ -H 'Content-Type: application/json' \ -H 'client_id: ci_live_198908HJDKJSH98789OHKJL' \ -H 'client_secret: cs_live_9827hofdsklOYYHJLJh' \ -H 'access_token: 493JKLHIU98789hLKH9HHJH' \ -d '{ "patient_mrn": "MRN-12345", "payment_method": "Card", "reference_number": "#123456", "location": "1404", "amount": 350, "notes": "Patient copay collected at front desk", "deposit_date": "2026-06-15" }' ``` ### Example Response ```json theme={null} { "success": true, "message": "Payment processing. A webhook event will be sent upon completion.", "payment_id": "123e4567e89b12d3a456426614174001", "job_id": 12345 } ``` The response includes: * **payment\_id**: Unique identifier for the created payment record. * **job\_id**: Job execution identifier for tracking the async operation. ### Error Responses #### Missing or Invalid Field If a required field is missing or invalid, the API returns a `400` with the specific field name: ```json theme={null} { "success": false, "message": "Missing or invalid required field: amount (must be a positive number)" } ``` #### Patient Not Found If the patient MRN cannot be resolved to an EMR patient, the API returns a `404`: ```json theme={null} { "success": false, "message": "Patient with MRN 'MRN-12345' not found. Please ensure the patient has been synced and has an EMR patient ID." } ``` #### User Not Found ```json theme={null} { "success": false, "message": "User not found." } ``` ### Webhook Notifications When the payment posting is complete, we will send a webhook to your registered endpoint. Here are examples of what those webhook payloads will look like: #### Success ```json theme={null} { "id": "evt_1J9X2q2eZvKYlo2CluR9g9gV", "access_token_reference_id": "user_1J9X2q2eZvKYlo2Cxyz", "object": "event", "created": "2026-06-15T10:30:00Z", "type": "payment.created", "job_id": "12345", "data": { "payment_id": "123e4567e89b12d3a456426614174001", "emr_transaction_id": "13969262", "payment_method": "Card", "amount": 350, "reference_number": "#123456", "patient_mrn": "MRN-12345" } } ``` #### Failure ```json theme={null} { "id": "evt_1J9X2q2eZvKYlo2CluR9g9gW", "access_token_reference_id": "user_1J9X2q2eZvKYlo2Cxyz", "object": "event", "created": "2026-06-15T10:35:00Z", "type": "payment.failed", "job_id": "12345", "data": { "payment_id": "123e4567e89b12d3a456426614174001", "failure_reason": "Failed to post payment" } } ``` ## OpenAPI ````yaml POST /payments openapi: 3.0.0 info: title: Cobalt API version: 1.0.1 description: API for interacting with Cobalt's EHR integration services servers: - url: https://api.usecobalt.com/v1 security: - ClientCredentials: [] ClientSecret: [] AccessToken: [] paths: /payments: post: summary: Create Payment description: >- Posts a patient payment back to the provider's EMR ledger. This is an asynchronous operation that returns immediately with a job_id, and sends a webhook notification upon completion. requestBody: required: true content: application/json: schema: type: object required: - patient_mrn - payment_method - reference_number - location - amount properties: patient_mrn: type: string description: >- Medical Record Number (MRN) of the patient the payment belongs to. payment_method: type: string description: >- Name of the payment method as configured in the EMR (e.g. "Card"). Resolved to the EMR's internal payment method id at post time. reference_number: type: string description: >- Your reference for the payment (e.g. a transaction or receipt number). Reference numbers may be reused across payments. location: type: string description: >- Identifier of the EMR location/facility the payment is posted against. amount: type: number description: Payment amount. Must be a positive number. notes: type: string description: >- Optional free-text note recorded with the payment in the EMR. deposit_date: type: string format: date description: >- Optional deposit date (YYYY-MM-DD). Defaults to today if omitted. responses: '200': description: Payment queued successfully content: application/json: schema: type: object properties: success: type: boolean message: type: string payment_id: type: string description: Unique identifier for the created payment record job_id: type: integer description: Job execution identifier for tracking the async operation '400': description: Bad request - Missing or invalid parameters content: application/json: schema: type: object properties: success: type: boolean message: type: string '404': description: User not found or Patient not found content: application/json: schema: type: object properties: success: type: boolean message: type: string example: User not found. '500': description: Internal server error content: application/json: schema: type: object properties: success: type: boolean message: type: string components: securitySchemes: ClientCredentials: type: apiKey in: header name: client_id ClientSecret: type: apiKey in: header name: client_secret AccessToken: type: apiKey in: header name: access_token ````