Images and multipart/form-data

Endpoints that accept an image (creating a coupon, event, transit, hotel or communication template, updating the wallet…) expect a multipart/form-data body. Each endpoint's reference page states the expected type.

A file can't travel inside JSON

Sending {"strip": "<PNG file>"} as application/json doesn't work. Use multipart/form-data, and let your HTTP client generate the Content-Type header (it contains the boundary).

The three multipart rules

1. Files are file fields: -F "strip=@strip.png;type=image/png".
2. Objects and arrays (colors, security, locations, displayOptions, iosHeader, date…) are sent as JSON strings: -F 'colors={"backgroundColor":"#131313","labelColor":"#9EE00D","foregroundColor":"#FFFFFF"}'
3. Booleans are sent as the text "true" or "false". Any other value counts as false.

Excerpt: a file and JSON objects in a coupon template

POST/couponsTry it →

• curl
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• CURL

curl -L 'https://api-v2.test.eldowallet.fr/coupons' \
-H 'Accept: application/json' \
-H 'x-lang: en' \
-H 'Authorization: Bearer <token>' \
-F 'strip=@"strip.png"' \
-F 'colors="{\"backgroundColor\":\"\#59358B\",\"labelColor\":\"\#F2FBCE\",\"foregroundColor\":\"\#FFFFFF\"}"' \
-F 'security="{\"enableOneTimeUse\":true}"'

File constraints

Image formats	PNG or JPEG
Image size	1 KB to 5 MB
CSV import	text/csv, 10 MB and 100,000 rows maximum
Per request	10 files and 50 MB per file maximum

An image outside these limits returns 400:VALIDATION_ERROR. A malformed multipart body returns 400:INVALID_MULTIPART, and an unsupported Content-Type returns 415:UNSUPPORTED_MEDIA_TYPE.

Updates

Most PATCH endpoints accept multipart or JSON. Use JSON when you aren't changing an image: it's simpler.

For recommended pass image dimensions, see the knowledge base.