> ## Documentation Index > Fetch the complete documentation index at: https://docs.lerian.studio/llms.txt > Use this file to discover all available pages before exploring further. # Create an outbound Pix refund (MED) > Issues a refund against a previously completed CASHIN transfer with a structured pacs.004 reasonCode. ## OpenAPI ````yaml /es/openapi/v3-current/pix-lerian-spi.yaml post /transfers/{id}/refunds openapi: 3.1.0 info: contact: name: Lerian Studio url: https://lerian.studio description: >- Public API for outbound Pix transfers, refunds, and scheduled payments. This release provides a mock-provider integration for testing; live BACEN connectivity is not included. license: name: Lerian Studio General License title: Pix Lerian — Payments version: 1.0.0 servers: - url: https://api.example.com/spi/v1 description: >- Replace the example host with the URL provided during environment onboarding. security: - BearerAuth: [] tags: - description: Create, list, and retrieve Pix refunds. name: Refunds - name: Scheduled Payments description: Register, list, retrieve, and cancel scheduled Pix payments. - description: Initiate, process, list, and retrieve outbound Pix transfers. name: Transfers paths: /transfers/{id}/refunds: post: tags: - Refunds summary: Create an outbound Pix refund (MED) description: >- Issues a refund against a previously completed CASHIN transfer with a structured pacs.004 reasonCode. operationId: createRefund parameters: - description: >- REQUIRED. Client-supplied replay key, at most 64 bytes. A request without it is refused with PIX-0030 @ 400 before the handler runs. Replaying the same key with a divergent method, URL or body is PIX-0031 @ 412. in: header name: X-Idempotency required: true schema: maxLength: 64 minLength: 1 type: string - description: Account UUID in: header name: X-Account-Id required: true schema: description: Account UUID examples: - 019606a1-3b4c-7d8e-9f01-234567890abc type: string - description: Original transfer UUID in: path name: id required: true schema: description: Original transfer UUID examples: - 0196070b-1234-7890-abcd-ef0123456789 type: string requestBody: content: application/json: schema: $ref: '#/components/schemas/CreateRefundBody' required: true responses: '201': content: application/json: schema: $ref: '#/components/schemas/RefundCashoutOutput' description: Created '400': content: application/json: example: code: PIX-0030 title: Idempotency Key Required message: >- The Idempotency-Key header is required for this operation and must be within the accepted length. schema: $ref: '#/components/schemas/LegacyErrorEnvelope' application/problem+json: example: type: https://errors.lerian.studio/v1/PIX-0403 title: Bad Request status: 400 detail: Missing or malformed required fields for refund. code: PIX-0403 schema: $ref: '#/components/schemas/Detail' description: >- Missing, duplicated, or malformed request headers/path/body fields, an invalid amount/reason, or another invalid refund input (PIX-0001-0003, PIX-0010, PIX-0015, PIX-0017, PIX-0403). X-Idempotency absent or longer than 64 bytes (PIX-0030). Legacy {code,title,message} envelope, NOT problem+json. '404': content: application/problem+json: example: type: https://errors.lerian.studio/v1/PIX-0400 title: Not Found status: 404 detail: Original transfer does not exist. code: PIX-0400 schema: $ref: '#/components/schemas/Detail' description: >- The original transfer does not exist in the calling account scope (PIX-0400). '409': content: application/problem+json: example: type: https://errors.lerian.studio/v1/PIX-0406 title: Conflict status: 409 detail: The refund changed during this request. Retry the operation. code: PIX-0406 schema: $ref: '#/components/schemas/Detail' description: >- A concurrent refund update won the race, or the operation reached another conflicting state (PIX-0406, PIX-0704). '412': content: application/json: example: code: PIX-0031 title: Idempotency Key Conflict message: The Idempotency-Key was already used with a different request. schema: $ref: '#/components/schemas/LegacyErrorEnvelope' description: >- X-Idempotency replayed with a divergent request -- a different method, URL (including the path parameter) or body (PIX-0031). Legacy {code,title,message} envelope, NOT problem+json. '415': content: application/problem+json: example: type: https://errors.lerian.studio/v1/PIX-0016 title: Unsupported Media Type status: 415 detail: >- The request body must be sent with Content-Type: application/json. code: PIX-0016 schema: $ref: '#/components/schemas/Detail' description: >- The non-empty request body is missing an accepted JSON Content-Type (PIX-0016). '422': content: application/problem+json: example: type: https://errors.lerian.studio/v1/PIX-0401 title: Unprocessable Entity status: 422 detail: Original transfer is not in COMPLETED status. code: PIX-0401 schema: $ref: '#/components/schemas/Detail' description: >- The original transfer is not completed, the refund exceeds the remaining amount, or the ledger account/balance cannot be used (PIX-0401, PIX-0402, PIX-0328, PIX-0329). '500': content: application/problem+json: example: type: https://errors.lerian.studio/v1/PIX-0000 title: Internal Server Error status: 500 detail: >- The server could not complete the request. Please try again later. code: PIX-0000 schema: $ref: '#/components/schemas/Detail' description: Unexpected server error (PIX-0000). '502': content: application/problem+json: example: type: https://errors.lerian.studio/v1/PIX-0404 title: Bad Gateway status: 502 detail: >- The server could not complete the request. Please try again later. code: PIX-0404 schema: $ref: '#/components/schemas/Detail' description: A required upstream service failed (PIX-0404, PIX-0405, PIX-0705). '503': content: application/json: example: code: PIX-0032 title: Idempotency Unavailable message: >- The request was not processed because the idempotency store is unavailable. Please retry. schema: $ref: '#/components/schemas/LegacyErrorEnvelope' description: >- Replay cache unavailable on this fail-closed route, so the mutation was refused rather than executed without replay protection (PIX-0032). Legacy {code,title,message} envelope, NOT problem+json. default: content: application/problem+json: schema: $ref: '#/components/schemas/Detail' description: Error components: schemas: CreateRefundBody: additionalProperties: false properties: amount: description: Refund amount examples: - '100.00' type: string reason: description: Human-readable refund reason examples: - Estorno solicitado pelo pagador type: string reasonCode: description: pacs.004 RtrRsnInf reason code examples: - MD06 type: string required: - amount - reasonCode - reason type: object RefundCashoutOutput: additionalProperties: false properties: accountId: examples: - 019606a0-1a2b-7c3d-8e4f-567890123abc type: string amount: examples: - '100.00' type: string createdAt: examples: - '2026-05-06T10:45:00Z' format: date-time type: string deletedAt: format: date-time type: string description: examples: - Estorno solicitado pelo pagador type: string id: examples: - 019606b1-3b4c-7d8e-9f01-234567890dee type: string ledger: $ref: '#/components/schemas/LedgerInfo' metadata: additionalProperties: {} type: object originalEndToEndId: examples: - E12345678202605061030abcdef12345 type: string reasonCode: examples: - MD06 type: string returnEndToEndId: examples: - D12345678202605061045fedcba54321 type: string status: examples: - COMPLETED type: string type: examples: - OUTBOUND type: string updatedAt: examples: - '2026-05-06T10:45:30Z' format: date-time type: string required: - id - originalEndToEndId - status - type - amount - reasonCode - createdAt - updatedAt type: object LegacyErrorEnvelope: additionalProperties: false properties: code: description: PIX-XXXX error code type: string message: description: Human-readable error message type: string title: description: Short error title type: string required: - code - title - message type: object Detail: additionalProperties: false properties: code: description: >- Stable, machine-readable domain error code scoped to the emitting service (format: -NNNN). examples: - ERR-0001 type: string detail: description: >- A human-readable explanation specific to this occurrence of the problem. examples: - Property foo is required but is missing. type: string errors: description: Optional list of individual error details items: $ref: '#/components/schemas/ErrorDetail' type: - array - 'null' instance: description: >- A URI reference that identifies the specific occurrence of the problem. examples: - https://example.com/error-log/abc123 format: uri type: string status: description: HTTP status code examples: - 400 format: int64 type: integer title: description: >- A short, human-readable summary of the problem type. This value should not change between occurrences of the error. examples: - Bad Request type: string type: default: about:blank description: A URI reference to human-readable documentation for the error. examples: - https://example.com/errors/example format: uri type: string upstream: $ref: '#/components/schemas/Upstream' description: >- RFC 9457 extension member: the error a proxied third-party provider reported. Absent unless the emitting service explicitly surfaced one. type: object LedgerInfo: additionalProperties: false properties: destinationOperationId: examples: - 019606a5-7f80-7182-3c4d-56789012cdf1 type: string revert: $ref: '#/components/schemas/LedgerRevertInfo' sourceOperationId: examples: - 019606a5-7f80-7182-3c4d-56789012cdf0 type: string transactionId: examples: - 019606a5-7f80-7182-3c4d-56789012cdef type: string type: object ErrorDetail: additionalProperties: false properties: location: description: >- Where the error occurred, e.g. 'body.items[3].tags' or 'path.thing-id' type: string message: description: Error message text type: string value: description: The value at the given location type: object Upstream: additionalProperties: false properties: code: description: The upstream provider's own error code, verbatim. examples: - E4001 type: string message: description: >- The upstream provider's own error message, verbatim (bounded, never its raw response body). examples: - account not found at provider type: string type: object LedgerRevertInfo: additionalProperties: false properties: destinationOperationId: examples: - 019606a5-7f80-7182-3c4d-56789012cdf1 type: string sourceOperationId: examples: - 019606a5-7f80-7182-3c4d-56789012cdf0 type: string transactionId: examples: - 019606a5-7f80-7182-3c4d-56789012cdef type: string type: object securitySchemes: BearerAuth: bearerFormat: JWT description: JWT bearer token issued by the identity provider. scheme: bearer type: http ````