# Upload an XMTP or Push Protocol attachment

Upload an XMTP or Push Protocol attachment. Quota enforced per user. Authentication is required using domain owner signature.

Endpoint: POST /user/{domain}/attachment
Version: 1.0.0

## Path parameters:

  - `domain` (string, required)
    The domain name to query profile data

## Header parameters:

  - `x-auth-domain` (string, required)
    The domain to authorize
    Example: "mydomain.tld"

  - `x-auth-expires` (string, required)
    The expiration time of the signature
    Example: 1765522015090

  - `x-auth-signature` (string, required)
    The signature generating using domain owner private key
    Example: "0b62348775da58077591e2d20506371e8d94a5a83031f34b9ac85845d3463e73b0f0a500875830785c093515806e354cda6c217acab0fce5245d662eff4105f5e1c"

## Request fields (application/json):

  - `attachment` (object)

  - `attachment.base64` (string)
    Base64 encoded string of the image data
    Example: "aGVsbG8gd29ybGQK"

  - `attachment.type` (string)
    MIME type of the base64 encoded file (image/jpeg or image/png)
    Example: "image/png"

## Response 200 fields (application/json):

  - `url` (string)
    Public URL to access the attachment
    Example: "https://path/to/attachment"


## Response 400 fields

## Response 404 fields

## Response 409 fields