---
title: "POST /echo"
method: POST
path: "/echo"
tags: ["echo"]
---

# POST /echo

`POST /echo`

## Request

- Base URL: `https://financial-services.developer.worldline.com` (the document declares no server; this is the origin it was published from)
- URL: `https://financial-services.developer.worldline.com/echo`
- Auth: none declared
- TypeScript: <https://skmtc.dev/worldline/apis/referential-ws-client/docs/echo/post.ts> (a function with typed inputs; its response is checked against the schema)

Echo function to test the availability of the web service. `header`'s `keyTag` and `iv` are not used in this operation.

## Request body

- EchoMessage: EchoMessage DTO resource representation.
  - `header` Header, required: Metadata of the message.
    - `requestId` string, uuid, required: Unique identifier of the request.
    - `service` string, required: Service code (defined during project).
    - `issuerCode` string, required: Issuer code.
    - `subIssuerCode` string, required: Sub-issuer code.
    - `keyTag` string: Key indicator shared between client and server. If `keyTag` is provided, then this reference should be used to encrypt / decrypt sensitive data (PAN, expiry date).
    - `iv` union
      - string: IV value used for **CBC** encryption. IV is provided only if HUB's IV configuration is set to "RANDOM".
      - string: IV value used for **GCM** encryption. IV is provided only if HUB's IV configuration is set to "RANDOM".
  - `body` EchoBody, required: EchoBody DTO resource representation.
    - `timestamp` string, yyyy-MM-dd HH:mm:ss.SSS, required: Timestamp.
  - `footer` Footer: Not used.
    - `signature` Signature: Not used. For signature feature, please refer to the `signature` field at the root of the messages.
      - `algorithm` string: Algorithm.
      - `keyInfo` string: Key info.
      - `value` string: Value.

## Response `200`

OK.

- EchoMessage: EchoMessage DTO resource representation.
  - `header` Header, required: Metadata of the message.
    - `requestId` string, uuid, required: Unique identifier of the request.
    - `service` string, required: Service code (defined during project).
    - `issuerCode` string, required: Issuer code.
    - `subIssuerCode` string, required: Sub-issuer code.
    - `keyTag` string: Key indicator shared between client and server. If `keyTag` is provided, then this reference should be used to encrypt / decrypt sensitive data (PAN, expiry date).
    - `iv` union
      - string: IV value used for **CBC** encryption. IV is provided only if HUB's IV configuration is set to "RANDOM".
      - string: IV value used for **GCM** encryption. IV is provided only if HUB's IV configuration is set to "RANDOM".
  - `body` EchoBody, required: EchoBody DTO resource representation.
    - `timestamp` string, yyyy-MM-dd HH:mm:ss.SSS, required: Timestamp.
  - `footer` Footer: Not used.
    - `signature` Signature: Not used. For signature feature, please refer to the `signature` field at the root of the messages.
      - `algorithm` string: Algorithm.
      - `keyInfo` string: Key info.
      - `value` string: Value.

## Other responses

- `400`: Bad Request.
- `403`: Forbidden.

---

[API](https://skmtc.dev/worldline/apis/referential-ws-client.md) - [All operations](https://skmtc.dev/worldline/apis/referential-ws-client/llms.txt) - [OpenAPI document](https://skmtc.dev/worldline/apis/referential-ws-client/revisions/21cb2439c982?raw)