Describe image API

From $0.01 per successful call · failed calls are never charged · no account needed · Markdown version: /guides/describe-image-api.md

Give an image URL and get a detailed description including any visible text, or ask a question about the image; PNG, JPEG, WebP and GIF up to 3 MB.

When an agent wants this

Describe image, ask about it: ask what is in an image or photo at a URL and get a text description or answer $0.01

Vision model for an image at a public URL: get a detailed description including any visible text, or pass a question to ask something specific about the image. Accepts PNG, JPEG, WebP and GIF up to 3 MB. Use for alt text, OCR-style reading of screenshots, chart reading and content checks.

Inputs: url (required): Absolute http(s) URL of a PNG, JPEG, WebP or GIF image (max 3 MB); question: Optional question about the image (max 300 characters); default is a detailed description.

Not in the free calls (it costs capacity per call); pay from the first call.

With a card key from /credits, in a header or, when your client can only fetch a URL, in the URL:

curl -H "Authorization: Bearer adt_…" "https://tools.funwords.eu/describe?url=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2F4%2F47%2FPNG_transparency_demonstration_1.png"
curl "https://tools.funwords.eu/describe?url=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2F4%2F47%2FPNG_transparency_demonstration_1.png&api_key=adt_…"

Without a key the same URL answers 402 Payment Required with x402 and MPP terms, so a wallet client pays USDC per call and retries. Over MCP (https://tools.funwords.eu/mcp) this tool is describe.

Example result
{
  "url": "https://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png",
  "question": "What colors are the dice?",
  "description": "The dice are blue, red, green, and yellow.",
  "model": "@cf/meta/llama-4-scout-17b-16e-instruct"
}

Tool page, inputs and limits

Questions

Which model answers?

A vision model on Workers AI; its name is returned in the model field.

Which formats and sizes?

PNG, JPEG, WebP and GIF up to 3 MB, by public URL.

How do I pay?

Each successful call costs the tool's price; failed calls are not charged. Then pay with card credits from $1 (the key goes in an Authorization header or as api_key= in the URL) or per call in USDC over x402 or MPP. No account is needed.