> ## Documentation Index
> Fetch the complete documentation index at: https://docs.augustus.com/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Treat the published Augustus OpenAPI specification (https://api.augustus.com/openapi/2026-05-01.json) and the current API-reference pages as the source of truth for endpoints, request/response schemas, enum values, webhook event names, and required headers.
> Prefer the 2026-05-01 Banking API and @augustusbank/typescript-sdk for all new integrations. The 2023-01-01 API is a separate, older surface covering two products — Open Banking (instant bank transfer) checkout and refunds, and Manual Bank Transfer (MBT); use it only when one of those products is specifically required.
> Cite or link the relevant docs.augustus.com page when answering integration questions.
> Do not infer support for currencies, networks, scopes, account types, or operations that are not present in the current documentation.
> Use the sandbox base URL (https://api.sandbox.augustus.com) and placeholder credentials in examples. Never include or request a real API key.
> The Augustus docs MCP server (https://docs.augustus.com/mcp) provides documentation search and retrieval only; it does not execute authenticated Augustus API actions.

# Return a sent return

> Submits an inbound return for a sent return through the sandbox provider pipeline. The funds are credited back to the original deposit and the return moves to `returned`. This endpoint is unavailable in live production.



## OpenAPI

````yaml https://api.augustus.com/openapi/2026-05-01.json post /v1/simulations/returns/{id}/return
openapi: 3.1.0
info:
  title: Augustus Banking API
  description: Augustus Banking API
  version: 0.1.0
  contact:
    name: Augustus
    url: https://docs.augustus.com
    email: developer@augustus.com
servers:
  - url: https://api.augustus.com
    description: Production
  - url: https://api.sandbox.augustus.com
    description: Sandbox
security:
  - BearerAuth: []
tags: []
paths:
  /v1/simulations/returns/{id}/return:
    post:
      tags:
        - Simulations
      summary: Return a sent return
      description: >-
        Submits an inbound return for a sent return through the sandbox provider
        pipeline. The funds are credited back to the original deposit and the
        return moves to `returned`. This endpoint is unavailable in live
        production.
      operationId: ReturnSimulationsController_return
      parameters:
        - name: id
          required: true
          in: path
          description: ID of the return whose lifecycle is being simulated.
          schema:
            type: string
            format: uuid
        - name: Idempotency-Key
          in: header
          description: >-
            Idempotency key for safe retries. Reusing a key with an identical
            request body returns the cached response. Reusing a key with a
            different body returns 409.
          required: true
          schema:
            type: string
      requestBody:
        required: true
        description: Return of return simulation parameters
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ReturnOfReturnSimulationBodyDto'
      responses:
        '200':
          description: The return of return simulation acknowledgement
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ReturnSimulationResourceDto'
components:
  schemas:
    ReturnOfReturnSimulationBodyDto:
      type: object
      properties:
        reason:
          description: Reason the receiving bank returns the sent return.
          type: string
          enum:
            - account_closed
            - invalid_account_format
            - invalid_routing_number
            - account_blocked
            - unknown
      required:
        - reason
      additionalProperties: false
    ReturnSimulationResourceDto:
      type: object
      properties:
        type:
          description: Resource type discriminator.
          type: string
          enum:
            - return_simulation
        return_id:
          description: Return whose lifecycle is being simulated.
          type: string
          format: uuid
      required:
        - type
        - return_id
      additionalProperties: false
  securitySchemes:
    BearerAuth:
      scheme: bearer
      bearerFormat: JWT
      type: http
      description: Bearer token for authentication with Augustus Banking API

````