> ## Documentation Index > Fetch the complete documentation index at: https://developer.happenstance.ai/llms.txt > Use this file to discover all available pages before exploring further. # Get Usage > Get credit balance, purchase history, usage history, and Auto Reload settings for the authenticated user. ## OpenAPI ````yaml /openapi.json get /v1/usage openapi: 3.1.0 info: title: Happenstance API description: > The Happenstance API provides programmatic access to person research and network search functionality. ## Authentication All API endpoints require authentication using an API key. Include your API key in the `Authorization` header: ``` Authorization: Bearer YOUR_API_KEY ``` ## Error Responses All errors follow RFC 7807 Problem Details format with `application/problem+json` content type. Example error response: ```json { "type": "https://developer.happenstance.ai/errors/empty-field", "title": "Bad Request", "status": 400, "detail": "Description must not be empty", "instance": "/v1/research" } ``` version: 0.1.0 servers: - url: https://api.happenstance.ai description: Production security: [] paths: /v1/usage: get: summary: Get Usage description: >- Get credit balance, purchase history, usage history, and Auto Reload settings for the authenticated user. operationId: get_usage_v1_usage_get responses: '200': description: Successful Response headers: Link: description: >- RFC 8288 Web Linking header for HATEOAS. Contains URIs to related resources. schema: type: string example: ; rel="self" content: application/json: schema: $ref: '#/components/schemas/GetUsageResponseV1' '400': description: Bad Request content: application/json: schema: $ref: '#/components/schemas/ProblemDetailV1' '401': description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/ProblemDetailV1' '402': description: Payment Required content: application/json: schema: $ref: '#/components/schemas/ProblemDetailV1' '403': description: Forbidden content: application/json: schema: $ref: '#/components/schemas/ProblemDetailV1' '404': description: Not Found content: application/json: schema: $ref: '#/components/schemas/ProblemDetailV1' '410': description: Gone content: application/json: schema: $ref: '#/components/schemas/ProblemDetailV1' '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/ProblemDetailV1' '500': description: Internal Server Error content: application/json: schema: $ref: '#/components/schemas/ProblemDetailV1' '503': description: Service Unavailable content: application/json: schema: $ref: '#/components/schemas/ProblemDetailV1' security: - HTTPBearer: [] components: schemas: GetUsageResponseV1: properties: balance_credits: type: integer title: Balance Credits description: >- Current credit balance (can be negative if credits consumed without sufficient balance) has_credits: type: boolean title: Has Credits description: Whether the user has credits available (balance > 0) purchases: items: $ref: '#/components/schemas/ApiPurchaseV1' type: array title: Purchases description: List of credit purchases, most recent first usage: items: $ref: '#/components/schemas/ApiUsageV1' type: array title: Usage description: List of credit usage records, most recent first auto_reload: anyOf: - $ref: '#/components/schemas/AutoReloadSettingsV1' - type: 'null' description: Auto Reload settings if configured additionalProperties: false type: object required: - balance_credits - has_credits - purchases - usage title: GetUsageResponseV1 description: >- Response from GET /v1/usage - retrieving user's credit purchases and usage history. ProblemDetailV1: properties: type: type: string title: Type description: A URI reference that identifies the problem type default: >- https://developer.happenstance.ai/api-reference/introduction#error-response-format title: type: string title: Title description: A short, human-readable summary of the problem status: type: integer title: Status description: The HTTP status code detail: anyOf: - type: string - type: 'null' title: Detail description: A human-readable explanation specific to this occurrence instance: anyOf: - type: string - type: 'null' title: Instance description: >- A URI reference that identifies the specific occurrence of the problem additionalProperties: false type: object required: - title - status title: ProblemDetailV1 description: RFC 7807 Problem Details for HTTP APIs ApiPurchaseV1: properties: id: type: string title: Id description: Unique identifier for the purchase credits: type: integer title: Credits description: Number of credits purchased purchased_at: type: string title: Purchased At description: When the purchase was made (ISO 8601 format) additionalProperties: false type: object required: - id - credits - purchased_at title: ApiPurchaseV1 description: A credit purchase record ApiUsageV1: properties: id: type: string title: Id description: Unique identifier for the usage credit_used: type: integer title: Credit Used description: Number of credits consumed created_at: type: string title: Created At description: When the usage was recorded (ISO 8601 format) resource_id: anyOf: - type: string - type: 'null' title: Resource Id description: >- ID of the resource that consumed the credits (search ID or research ID) resource_type: anyOf: - type: string - type: 'null' title: Resource Type description: 'Type of resource: ''search'' or ''research''' additionalProperties: false type: object required: - id - credit_used - created_at title: ApiUsageV1 description: A credit usage record AutoReloadSettingsV1: properties: enabled: type: boolean title: Enabled description: Whether Auto Reload is enabled threshold_credits: type: integer title: Threshold Credits description: Credits threshold that triggers Auto Reload reload_credit_amount: type: integer title: Reload Credit Amount description: Number of credits to purchase on Auto Reload last_reload_at: anyOf: - type: string - type: 'null' title: Last Reload At description: Last Auto Reload timestamp (ISO 8601 format) additionalProperties: false type: object required: - enabled - threshold_credits - reload_credit_amount title: AutoReloadSettingsV1 description: Auto Reload configuration securitySchemes: HTTPBearer: type: http scheme: bearer ````