Generate a single 1D barcode

Render a 1D barcode for a GTIN. Symbology is auto-selected from GTIN length unless overridden via barcode_type. Returns image bytes (image/svg+xml, image/png, application/postscript, or application/pdf).

Caching: responses are deterministic given the request body. The endpoint sets Cache-Control: public, max-age=2592000 (30 days) and a strong ETag over the image bytes. Clients sending If-None-Match with a matching ETag get 304 Not Modified.

POST /products/api/v1/barcode

Generate a single 1D barcode

cURL

curl --request POST \
  --url https://www.closient.com/products/api/v1/barcode/ \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '
{
  "gtin": "<string>",
  "barcode_type": "auto",
  "format": "svg",
  "module_width": 0.33,
  "module_height": 25,
  "font_size": 10,
  "quiet_zone": 6.5,
  "write_text": true,
  "embed_font": true
}
'

200

"<string>"

Authorizations

APIKeyHeaderAuthOAuthTokenAuthSessionAuth

X-API-Key · string · header · required

Body

application/json

Request body for synchronous 1D barcode generation.

gtin · string · required

GTIN (8/12/13/14 digits) or AI-bracketed string for GS1-128.

barcode_type · enum<string> · default: auto

Symbology. auto picks the right family from GTIN length.

Available options: auto, ean13, ean8, jan, upca, upce, itf14, ean14, code128, gs1_128, code39

format · enum<string> · default: svg

Output image format. svg is scalable vector output with embedded OCR-B HRT glyphs (the preferred print-shop format); png is raster output; eps is PostScript for legacy label-printer drivers; pdf (C-2852) is vector PDF for print houses — the SVG goes through svglib + reportlab so the PDF contains path operators, not a rasterised preview.

Available options: svg, png, eps, pdf

module_width · number · default: 0.33

Module (narrowest bar) width in millimeters. Default 0.33mm matches GS1 retail-scan recommendations. Increase to ~0.5-1.0mm for outer-case ITF-14 / shipping containers.

Required range: 0.1 <= x <= 2

module_height · number · default: 25

Symbol height in millimeters. Default 25.0mm matches GS1 retail minimum. Reduce for compact labels; increase for warehouse-scan distance.

Required range: 1 <= x <= 100

font_size · number · default: 10

Human-readable text size in points. Default 10pt. Values below 8pt switch Zint to its compact-text rendering (--small); values 8pt and above render at standard size.

Required range: 4 <= x <= 24

quiet_zone · number · default: 6.5

Quiet zone (white margin around the symbol) in millimeters. Default 6.5mm matches GS1 retail recommendations. Set to 0 to disable the quiet-zone markers entirely.

Required range: 0 <= x <= 20

write_text · boolean · default: true

Render the human-readable GTIN below the bars. Default true.

embed_font · boolean · default: true

Embed the OCR-B font in SVG output for portable rendering. Default true. No effect on PNG / EPS output.

Response

200

application/json

OK

The response is of type file.