Messages
A Message is a single entry within a Chat, containing text content and optional attachments.
Upload a Message Attachment
To add Message Attachments (Uploaded Files) to a Message, a multipart/form-data POST request to /openapi/v1/orders/{orderId}/upload-file
needs to be made for each Uploaded File/Attachment before creating a Message.
Mandatory fields:
orderIdin the URL.filein themultipart/form-datarequest Body.
Message Attachments restrictions
- Maximum allowed Attachments per Message:
10. - Maximum filesize per Message Attachment:
10MB(10,240 KB).
Request:
POST https://service-message-center.pp-de.metro-marketplace.cloud/openapi/v1/orders/9e159b23-5585-4482-b078-9a9e1db2b252/upload-file
Response:
A 201 Created response will be received containing the details of the Uploaded File.
{
"status": "success",
"message": "File uploaded successfully.",
"data": {
"fileId": "files/229dc41e-d3d5-4243-8789-53898cc69022/e13514f4-18fa-479e-88d7-e79eb3e02ef2/9aaba500-54dd-4ef5-b14d-f3190d157ee2",
"fileName": "Test Document.pdf",
"fileType": "application/pdf"
},
"metadata": []
}
Send a Message
To add a Message to an existing Chat, a POST request to /openapi/v1/chats/{chatId}/messages can be made.
Mandatory fields:
chatIdin the URL.contentin the request Body.
Optional fields:
attachments, includes the Uploaded Files data, in which case the Message Attachments restrictions apply and the following fields are mandatory:fileId, as provided by the File Upload endpoint's responsefileName, as provided by the File Upload endpoint's responsefileType, as provided by the File Upload endpoint's response based on the Supported Message Attachment Media Types:image/pngimage/jpgimage/jpegapplication/pdfapplication/vnd.ms-excelapplication/mswordapplication/vnd.ms-wordtext/plain
Behavior:
On each endpoint request the Automatic 'Mark as Seen' Behavior is applied.
Request:
POST https://service-message-center.pp-de.metro-marketplace.cloud/openapi/v1/chats/9e3e66e9-4025-4306-9278-c71ccee64fe5/messages
request Body with an Attachment:
{
"content": "Test OpenAPI 123",
"attachments": [
{
"fileId": "files/229dc41e-d3d5-4243-8789-53898cc69022/e13514f4-18fa-479e-88d7-e79eb3e02ef2/9aaba500-54dd-4ef5-b14d-f3190d157ee2",
"fileType": "application/pdf",
"fileName": "Test Document"
}
]
}
Response:
A 201 Created response will be received containing the details of the newly created Message.
{
"status": "success",
"message": "Message [9fd66bbe-cc4f-489e-810f-c136e3592326] has been created",
"data": {
"id": "9fd66bbe-cc4f-489e-810f-c136e3592326",
"chatId": "9eea824c-b69c-42c2-a9df-2cd545d57b50",
"senderId": "1ebeca48-baa3-40a2-8421-a2b12162008d",
"senderUserType": "SELLER",
"receiverId": "78dc45b5-d0ae-4155-b26a-2a238bfc2a35",
"content": "Test OpenAPI 123",
"seenAt": null,
"createdAt": "2025-09-09T15:46:34+00:00",
"attachments": [
{
"fileId": "files/229dc41e-d3d5-4243-8789-53898cc69022/e13514f4-18fa-479e-88d7-e79eb3e02ef2/9aaba500-54dd-4ef5-b14d-f3190d157ee2",
"fileType": "application/pdf",
"fileName": "Test Document",
"downloadUrl": "https://storage.googleapis.com/service-message-center-bucket-pp-de/files/229dc41e-d3d5-4243-8789-53898cc69022/..."
}
]
},
"metadata": []
}
Retrieve list of Messages in a Chat
To retrieve all Chat’s Messages (conversation history), a GET request can be made to /openapi/v1/chats/{chatId}/messages.
Behavior:
On each endpoint request the Automatic 'Mark as Seen' Behavior is applied.
Request:
GET https://service-message-center.sandbox.infra.metro-markets.cloud/openapi/v1/chats/9e3e66e9-4025-4306-9278-c71ccee64fe5/messages
Response:
{
"status": "success",
"message": "Messages for chatId [9eea824c-b69c-42c2-a9df-2cd545d57b50] fetched successfully",
"data": [
{
"id": "9fc8202f-b40d-46cb-bd5c-dcb341ac3551",
"chatId": "9eea824c-b69c-42c2-a9df-2cd545d57b50",
"senderId": "78dc45b5-d0ae-4155-b26a-2a238bfc2a35",
"senderUserType": "BUYER",
"receiverId": "136eb8b3-c0aa-44e6-86cb-a050587ac0a9",
"content": "Test message from buyer",
"seenAt": "2025-09-09T14:52:00+00:00",
"createdAt": "2025-09-02T13:13:42+00:00",
"attachments": [
{
"fileId": "files/229dc41e-d3d5-4243-8789-53898cc69022/e13514f4-18fa-479e-88d7-e79eb3e02ef2/9aaba500-54dd-4ef5-b14d-f3190d157ee2",
"fileType": "application/pdf",
"fileName": "Test Document",
"downloadUrl": "https://storage.googleapis.com/service-message-center-bucket-pp-de/files/229dc41e-d3d5-4243-8789-53898cc69022/..."
}
]
}
],
"metadata": []
}