openapi: 3.1.0 info: title: BILL v3 Authentication Organizations API description: 'REST API providing access to BILL''s Accounts Payable, Accounts Receivable, and Spend & Expense capabilities — bills, invoices, vendors, customers, payments, funding accounts, organizations, webhooks, and authentication workflows. Best-effort OpenAPI reconstruction from BILL''s public developer portal at https://developer.bill.com/docs/home. Authoritative reference and Postman collection live under https://developer.bill.com/reference and https://developer.bill.com/llms.txt. ' version: 3.0.0 contact: name: BILL Developer Portal url: https://developer.bill.com/docs/home license: name: Proprietary servers: - url: https://gateway.prod.bill.com/connect/v3 description: BILL production gateway (Connect v3) - url: https://gateway.stage.bill.com/connect/v3 description: BILL sandbox gateway (Connect v3) - url: https://api.bill.com/v3 description: BILL production API - url: https://api-sandbox.bill.com/v3 description: BILL sandbox API security: - sessionAuth: [] tags: - name: Organizations paths: /organizations: get: tags: - Organizations summary: List accessible organizations operationId: listOrganizations responses: '200': description: Organizations. /users/{userId}/restore: post: tags: - Organizations summary: Restore an archived user operationId: restoreUser parameters: - name: userId in: path required: true schema: type: string responses: '200': description: Restored. components: securitySchemes: sessionAuth: type: apiKey in: header name: sessionId description: 'Session identifier obtained from `POST /login`. Expires after 35 minutes of inactivity. A `devKey` (developer key) is also required on requests and is sent alongside `sessionId` in the appropriate header per BILL''s official reference. '