openapi: 3.0.3 info: title: Cross River Operating System (COS) Accounts ACH API description: 'The Cross River Operating System (COS) is a collection of RESTful APIs from Cross River Bank (an FDIC-member bank) for embedded finance and Banking-as-a-Service - deposit accounts, ACH, wires, instant payments (RTP / FedNow / CRNow), card issuing and management, lending, and customer management (KYC / onboarding). COS is organized around REST with object-oriented URLs and JSON responses, and uses OAuth 2.0 (client credentials grant) to issue a signed JWT Bearer access token that must be sent on every request. ACCESS MODEL: Cross River is a regulated bank and COS access is partner/enterprise-gated. Programs are onboarded via Cross River sales and a relationship manager, who provision client_id / client_secret credentials for the sandbox (https://sandbox.crbcos.com) and, after go-live, for production. The public production base URL is not published in the open documentation. GROUNDING NOTE: The paths, methods, and module base URLs in this document are grounded in the public Cross River developer documentation at docs.crossriver.com (as of 2026-07-12). Because the live sandbox is credential-gated, request and response BODY SCHEMAS below are MODELED representative structures, not copied from the credential-gated OpenAPI / Postman collection Cross River shares with onboarded partners. Verify exact field names and required properties against the official reference and the partner-provided collection.' version: '1.0' contact: name: Cross River url: https://www.crossriver.com/ license: name: Proprietary url: https://www.crossriver.com/ servers: - url: https://sandbox.crbcos.com description: COS sandbox host for the core modules (Core, ACH, Wires, RTP, Cards, etc.). Requires partner-provisioned OAuth2 credentials. Production host is issued separately during go-live and is not publicly documented. - url: https://arixapisandbox.crbnj.net description: Lending / loan origination sandbox host (separate from the core COS host). security: - oauth2ClientCredentials: [] tags: - name: ACH description: ACH origination and receipt (COS Payments, /ach). paths: /ach/v1/payments: post: operationId: sendAchPayment tags: - ACH summary: Send an ACH payment description: Originates a single ACH payment over the Federal Reserve ACH network. Supports standard and same-day ACH. An idempotency-key header is recommended to safely retry. MODELED request body. parameters: - $ref: '#/components/parameters/IdempotencyKey' requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/AchPaymentInput' responses: '200': description: The created ACH payment. content: application/json: schema: $ref: '#/components/schemas/Payment' '401': $ref: '#/components/responses/Unauthorized' '422': $ref: '#/components/responses/ValidationError' components: responses: ValidationError: description: The request payload failed validation. content: application/json: schema: $ref: '#/components/schemas/Error' Unauthorized: description: Missing or invalid Bearer token. content: application/json: schema: $ref: '#/components/schemas/Error' schemas: AchPaymentInput: type: object description: MODELED. Verify required fields against the official reference. required: - amount - accountNumber properties: amount: type: number currency: type: string default: USD accountNumber: type: string description: The funding account number. counterparty: type: object additionalProperties: true sameDay: type: boolean secCode: type: string description: Standard Entry Class code (e.g. PPD, CCD, WEB). Error: type: object properties: error: type: object properties: code: type: string message: type: string details: type: object additionalProperties: true Payment: type: object properties: id: type: string status: type: string amount: type: number currency: type: string createdAt: type: string format: date-time parameters: IdempotencyKey: name: idempotency-key in: header required: false description: A client-generated UUID used to safely retry a request without duplicating it. schema: type: string format: uuid securitySchemes: oauth2ClientCredentials: type: oauth2 description: 'OAuth 2.0 client credentials grant. POST client_id, client_secret and grant_type=client_credentials to the COS identity provider token endpoint (sandbox: https://idptest.crbcos.com/connect/token; lending uses https://oauthtest.crbnj.net/connect/token). The response is a signed JWT that must be sent as `Authorization: Bearer ` on every request.' flows: clientCredentials: tokenUrl: https://idptest.crbcos.com/connect/token scopes: {}