journeyapi.devDocs
API reference

Caption an image

Turn an image into prompts that would plausibly produce it.

POST/v1/images/caption

The inverse of generation. Useful for building a prompt library from reference material, or for recovering a starting point from an image whose prompt you no longer have.

Body

imagestringrequired
A publicly reachable image URL.
ninteger
How many prompts to return, 1 to 4. Defaults to 4.
webhook_urlstring
Overrides the account webhook for this job only.
metadataobject
Up to 16 key-value pairs echoed back on the job, for correlating with your own records.
Request
curl -X POST https://api.journeyapi.dev/v1/images/caption \
  -H "Authorization: Bearer $JOURNEY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "image": "https://example.com/lighthouse.jpg" }'
Response · 200 OK, once complete
{
  "id": "job_01HQ8W1Q9A6BZT",
  "object": "job",
  "type": "caption",
  "status": "succeeded",
  "captions": [
    "a solitary lighthouse on a dark basalt cliff, heavy fog, long exposure, muted palette",
    "coastal lighthouse at dusk, volcanic rock, sea mist, cinematic wide shot",
    "minimalist seascape with a white lighthouse, low cloud, cold light, 35mm",
    "storm-lit lighthouse above black rock, spray, desaturated, documentary photography"
  ],
  "cost_usd": 0.01,
  "created_at": "2026-09-18T09:18:02Z",
  "completed_at": "2026-09-18T09:18:05Z"
}