openapi: 3.1.0
info:
  title: Increase Account Numbers External Accounts API
  description: Increase is a bank-grade payments and financial infrastructure platform that exposes a single REST API for moving and holding money in the United States. This document models the primary resources of the Increase API - Accounts, Account Numbers, Cards, Card Payments, ACH / Wire / Real-Time Payments / Check transfers, Transactions, Entities, Events and webhooks, Bookkeeping, Card Profiles and Digital Wallets, Lockboxes, and Simulations. It is grounded in Increase's public OpenAPI 3.1 spec (https://api.increase.com/openapi.json) and the Stainless-generated SDKs. Authentication is a Bearer API key. All endpoints are HTTPS REST; state changes are delivered as Events over HTTP webhooks (no WebSocket surface). Requests support idempotency via the `Idempotency-Key` header. This is a representative, not exhaustive, subset of the full API.
  version: 0.0.1
  contact:
    name: Increase
    url: https://increase.com
  license:
    name: Increase Documentation
    url: https://increase.com/documentation
servers:
- url: https://api.increase.com
  description: Production
- url: https://sandbox.increase.com
  description: Sandbox
security:
- bearerAuth: []
tags:
- name: External Accounts
  description: Counterparty bank accounts you send to or debit.
paths:
  /external_accounts:
    get:
      operationId: listExternalAccounts
      tags:
      - External Accounts
      summary: List External Accounts
      responses:
        '200':
          description: A list of External Accounts.
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/ExternalAccount'
    post:
      operationId: createExternalAccount
      tags:
      - External Accounts
      summary: Create an External Account
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - routing_number
              - account_number
              - description
              properties:
                routing_number:
                  type: string
                account_number:
                  type: string
                description:
                  type: string
                funding:
                  type: string
                  enum:
                  - checking
                  - savings
                  - other
      responses:
        '200':
          description: The created External Account.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ExternalAccount'
  /external_accounts/{external_account_id}:
    parameters:
    - name: external_account_id
      in: path
      required: true
      schema:
        type: string
    get:
      operationId: retrieveExternalAccount
      tags:
      - External Accounts
      summary: Retrieve an External Account
      responses:
        '200':
          description: The External Account.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ExternalAccount'
    patch:
      operationId: updateExternalAccount
      tags:
      - External Accounts
      summary: Update an External Account
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                description:
                  type: string
                status:
                  type: string
                  enum:
                  - active
                  - archived
      responses:
        '200':
          description: The updated External Account.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ExternalAccount'
  /routing_numbers:
    get:
      operationId: listRoutingNumbers
      tags:
      - External Accounts
      summary: List Routing Numbers
      description: Look up which real-time payment rails a given routing number supports.
      parameters:
      - name: routing_number
        in: query
        required: true
        schema:
          type: string
      responses:
        '200':
          description: Routing number details.
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      type: object
                      additionalProperties: true
components:
  schemas:
    ExternalAccount:
      type: object
      properties:
        id:
          type: string
        routing_number:
          type: string
        account_number:
          type: string
        description:
          type: string
        funding:
          type: string
          enum:
          - checking
          - savings
          - other
        status:
          type: string
          enum:
          - active
          - archived
        type:
          type: string
          example: external_account
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: 'Increase API key passed as `Authorization: Bearer YOUR_API_KEY`. Keys are environment-scoped (production vs sandbox). OAuth is also supported for platform / Increase-for-platforms integrations.'