> ## Documentation Index > Fetch the complete documentation index at: https://docs.getcarbon.co/llms.txt > Use this file to discover all available pages before exploring further. # Create Guarantor > Add a guarantor to a loan application. ## Overview Adds a guarantor to the loan. The guarantor will receive an invitation via the `clientPath` link to complete their form. This step is optional unless required by the underwriting decision. ### Request **Method:** `POST`\ **URL:** `/v1/loans/:applicationId/guarantor` #### Parameters | Name | In | Type | Required | Description | | --------------- | ------ | -------- | -------- | --------------------------- | | `x-carbon-key` | Header | `string` | Yes | API key for authentication. | | `applicationId` | Path | `string` | Yes | Application ID. | #### Request Body ```json theme={null} { "first_name": "Bola", "last_name": "Akin", "phone": "08099887766", "email": "bola.akin@example.com" } ``` | Field | Type | Required | Description | | ------------ | ------ | -------- | --------------------------- | | `first_name` | string | Yes | Guarantor's first name | | `last_name` | string | Yes | Guarantor's last name | | `phone` | string | Yes | Valid Nigerian phone number | | `email` | string | Yes | Valid email address | ### Response #### 201 Created ```json theme={null} { "status": "success", "data": { "id": 7, "firstName": "Bola", "lastName": "Akin", "phoneNumber": "08099887766", "emailAddress": "bola.akin@example.com", "clientPath": "https://app.carbon.ng/guarantor", "loanOfferId": 42, "tokenExpiresAt": "2025-01-22T10:00:00.000Z", "inviteSentAt": null, "submittedAt": null } } ``` | Field | Description | | ---------------- | ------------------------------------------------- | | `clientPath` | Link sent to the guarantor to complete their form | | `tokenExpiresAt` | Expiry of the guarantor invite link | | `submittedAt` | Populated when the guarantor completes the form | #### Error Responses | Status | Message | Cause | | ------ | --------------------------------------- | ------------------------------ | | 400 | `first_name is required` | Field missing | | 400 | `last_name is required` | Field missing | | 400 | `phone must be a valid Nigerian number` | Invalid or missing phone | | 400 | `email must be a valid email address` | Invalid or missing email | | 400 | `Application not found` | Invalid `applicationId` | | 422 | `Application has no loan ID` | Application not yet registered | ## OpenAPI ````yaml POST /v1/loans/{applicationId}/guarantor openapi: 3.0.0 info: title: Carbon Business API description: >- ## Welcome to our API Developer Documentation Carbon aims to unlock the full potential of your business with a feature-rich account designed for growth. ## Integrations We aim to provide our APIs for developers and businesses to offer financial services to their existing customer base through REST APIs without doing the heavy lifting. Our API has predictable resource-oriented URLs, accepts form-encoded request bodies, returns JSON-encoded responses, and uses standard HTTP response codes, authentication, and verbs. ### Authentication `Authorization : API Key` Header `x-carbon-key : value` `x-carbon-key` can be generated via developer page on Carbon Business | Environment | URL | | --- | --- | | Live | | | Sandbox | [https://carbonapistagingsecure.getcarbon.co/baas/api](https://carbonapistagingsecure.getcarbon.co/baas/api) | ### **Handling Errors** We use the conventional HTTP response codes to indicate the success or failure of an API request. Codes in the 2xx range indicate success. Codes in the 4xx range indicate an error that failed given the information provided (e.g., a required parameter was omitted, etc.). Codes in the 5xx range indicate an error with our servers. | Error | Description | | --- | --- | | 400 - Bad Request | The request was unacceptable, often due to missing a required parameter. | | 401 - Unauthorized | Not a valid API key was provided. | | 402 - Request Failed | The parameters were valid but the request failed. | | 403 - Forbidden | The API key doesn't have permission to perform the request. | | 404 - Not Found | The requested resource doesn't exist. | | 429 - Too Many Requests | Too many requests hit the API | | 500, 502, 503, 504 - Server Errors | System Error | version: 1.0.0 servers: - url: https://carbonapistagingsecure.getcarbon.co/baas/api description: >- Replace {{base_url}} with your API base URL (e.g., https://api.example.com) security: - apikeyAuth: [] tags: - name: Accounts description: >- Virtual accounts are generated account details (account number and bank) that allow Carbon Business merchants to receive payments from customers via NGN bank transfer. This is currently only available in naira (NGN). Virtual accounts are either dynamic (temporary) or static (permanent). A dynamic account number expires after handling a transaction, while a static account number doesn't expire. **Static Account** Creating static accounts can be useful when receiving recurring payments through bank transfers. The process involves generating a static virtual account with customer information. Once payment is made, we will send you a webhook notification, which you can then manage. **Dynamic Account** Creating dynamic accounts can be useful when receiving one-time payments through bank transfers. The process involves generating a dynamic virtual account with a set amount for the customer during checkout. Once payment is made, we will send you a webhook notification, which you can then manage. Key things you can do with these endpoints: - Create an account - Retreive an account - Verify Transaction - Retreive a list of transactions - name: Accounts > Transactions - name: Banks description: |- - Get a list of banks and financial institutions - Verify/resolve account details - name: Customers description: >- This collection contains a set of API endpoints to manage customer-related operations for an application. The endpoints allow for creating a new customer, retrieving a list of all customers, and fetching details of a single customer. - Create Customer - Fetch Customer/Customers - name: Payout description: |- - Make Transfer - Verify Transfer - name: Status description: '- Service Health check' - name: Verification - name: Webhook description: |- ## EVENTS `account.incoming-transaction` ``` json { "event": "account.incoming-transaction", "data": { "id": "string", "amount": "float", "currency": "string", "transactionType": "string", "entryDate": "datetime", "uniqueRef": "string", "account": { "id": "string", "bankAccount": { "accountName": "string", "accountNumber": "string", "bank": { "code": "string", "name": "string" } }, "static": boolean, "currency": "string", "clientId": "string" } } } ``` `account.outgoing-transaction` ``` json { "event": "account.outgoing-transaction", "data": { "id": "string", "amount": "float", "currency": "string", "transactionType": "string", "entryDate": "datetime", "uniqueRef": "string", "account": { "id": "string", "bankAccount": { "accountName": "string", "accountNumber": "string", "bank": { "code": "string", "name": "string" } }, "static": boolean, "currency": "string", "clientId": "string" } } } ``` - name: Loans description: >- Partner lending API. Enables fintech partners to originate business loans for their end-customers. - Enroll customers for lending and trigger KYC - Submit loan applications and supporting documents - Manage offer acceptance, disbursement account, and post-offer steps - Charge repayments and retrieve repayment schedules paths: /v1/loans/{applicationId}/guarantor: post: tags: - Loans summary: Add Guarantor description: >- Adds a guarantor to the loan application. Required when the lending engine determines a guarantor is needed. ### Request Body - `first_name` (string, required): Guarantor's first name. - `last_name` (string, required): Guarantor's last name. - `phone` (string, required): Guarantor's phone number. - `email` (string, required): Guarantor's email address. ### Response - `status` (string): success - `data.id` (number): Guarantor record ID - `data.first_name` (string): Guarantor's first name - `data.last_name` (string): Guarantor's last name - `data.phone` (string): Guarantor's phone - `data.email` (string): Guarantor's email parameters: - name: x-carbon-key in: header schema: type: string required: true example: '{{access_token}}' - name: applicationId in: path schema: type: string required: true example: a1b2c3d4-e5f6-7890-abcd-ef1234567890 requestBody: description: Provide the required values for the request body. required: true content: application/json: schema: type: object required: - first_name - last_name - phone - email properties: first_name: type: string example: John last_name: type: string example: Doe phone: type: string example: '08012345678' email: type: string example: guarantor@example.com example: first_name: John last_name: Doe phone: '08012345678' email: guarantor@example.com responses: '200': description: Successful response content: application/json: schema: type: object example: status: success data: id: 1 first_name: John last_name: Doe phone: '08012345678' email: guarantor@example.com components: securitySchemes: apikeyAuth: type: apiKey in: header name: apikey description: Provide your API key in the 'apikey' header. ````