Molmo2 Image Captioner API Documentation

Molmo2 Image Captioner API Documentation

Playground

Molmo2-4B Image Captioner: Generate detailed, accurate captions for images with customizable detail levels (low, medium, high). Open-source vision-language model with object grounding capabilities. Ready-to-use REST API, no cold starts, affordable pricing.

Features

Molmo2 Image Captioner is an intelligent image understanding model that generates detailed captions and descriptions for any image. Upload an image and receive natural-language descriptions of scenes, objects, people, and context — with adjustable detail levels to match your workflow needs.

Perfect for content creators, accessibility teams, and developers building image understanding pipelines.

Why Choose This?

• Adjustable detail levels Choose from low, medium, or high detail to control caption depth — from quick summaries to comprehensive scene breakdowns.

• Rich visual understanding Understands context, objects, people, text, environments, and spatial relationships to produce coherent, meaningful descriptions.

• Flexible image input Accepts image uploads or public URLs for seamless integration into existing workflows.

• Fast and affordable Optimized for quick turnaround at just $0.002 per image.

• Production-ready API Ready-to-use REST endpoint with simple flat-rate pricing and no cold starts.

Parameters

Detail Level Options

• Low — Brief, high-level summary of the image content
• Medium — Balanced description with key elements and context (default)
• High — Comprehensive breakdown with fine-grained details

How to Use

1. Upload your image — drag and drop a file or paste a public image URL.
2. Select detail level — choose low, medium, or high based on your needs.
3. Submit — the model processes the image and returns a caption.
4. Use the output — integrate captions into your content, accessibility tools, or data pipelines.

Pricing

Simple flat-rate pricing — no hidden fees or complex calculations.

Best Use Cases

• Accessibility — Generate image descriptions for visually impaired users and screen readers.
• Content indexing — Create searchable metadata for image libraries and archives.
• Social media — Auto-generate alt text and captions for posts.
• Image SEO — Improve discoverability with rich text descriptions for visual content.
• E-commerce — Automatically describe product images for catalogs.
• Education — Describe visual materials for enhanced learning resources.

Notes

• If using a URL, ensure it is publicly accessible. A preview thumbnail in the interface confirms successful access.
• Clear, well-lit images yield the most accurate captions.
• Use high detail level for complex scenes; low detail for quick overviews.
• Supports common image formats including JPEG, PNG, and WebP.

Authentication

For authentication details, please refer to the Authentication Guide.

API Endpoints

Submit Task & Query Result

set -euo pipefail

export WAVESPEED_API_KEY="your-api-key"

REQUEST_BODY=$(cat <<'JSON'
{
  "image": "https://interactive-examples.mdn.mozilla.net/media/cc0-images/painted-hand-298-332.jpg",
  "detail_level": "medium"
}
JSON
)

# 1. Submit the prediction.
SUBMIT_RESPONSE=$(curl --silent --show-error --fail-with-body \
  -X POST "https://api.wavespeed.ai/api/v3/wavespeed-ai/molmo2/image-captioner" \
  -H "Authorization: Bearer ${WAVESPEED_API_KEY}" \
  -H "Content-Type: application/json" \
  -d "${REQUEST_BODY}")

TASK=$(printf '%s' "${SUBMIT_RESPONSE}" | jq 'if type == "object" and has("data") then .data else . end')
PREDICTION_ID=$(printf '%s' "${TASK}" | jq -r '.id // empty')
if [ -z "${PREDICTION_ID}" ]; then
  printf 'Submission response did not contain a prediction id
' >&2
  exit 1
fi
RESULT_URL=$(printf '%s' "${TASK}" | jq -r '.urls.get // empty')
if [ -z "${RESULT_URL}" ]; then RESULT_URL="https://api.wavespeed.ai/api/v3/predictions/${PREDICTION_ID}/result"; fi

# 2. Poll until the prediction finishes.
while true; do
  RESPONSE=$(curl --silent --show-error --fail-with-body \
    "${RESULT_URL}" \
    -H "Authorization: Bearer ${WAVESPEED_API_KEY}")
  RESULT=$(printf '%s' "${RESPONSE}" | jq 'if type == "object" and has("data") then .data else . end')
  STATUS=$(printf '%s' "${RESULT}" | jq -r '.status // empty')

  case "${STATUS}" in
    completed) printf '%s\n' "${RESULT}" | jq '.outputs'; break ;;
    failed|cancelled|timeout) printf '%s\n' "${RESULT}" | jq . >&2; exit 1 ;;
    created|processing) sleep 2 ;;
    *) printf 'Unexpected status: %s
' "${STATUS}" >&2; exit 1 ;;
  esac
done

Parameters

Task Submission Parameters

Request Parameters

Response Parameters

Result Request Parameters

Result Response Parameters