# fastapi.online Image Q&A

> fastapi.online Image Q&A is a paid API for AI agents from api.fastapi.online, paid per call via x402, $0.0015/call, status unknown (last checked 2026-09-14).

Answers natural-language questions about an uploaded image using a self-hosted visual question-answering model

## Facts

- Endpoint: POST https://api.fastapi.online/image-qa
- Price: $0.0015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fastapi-online-image-q-a-e590c047
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Av4xvZXmixvaXgxFUHk4D

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability fastapi-online-image-q-a-e590c047 -d '<json body>'
```

Example prompt: Look at this photo of my living room and tell me: does the furniture arrangement leave enough space near the window?

## When to prefer this

Choose this endpoint when you need to ask a specific, targeted question about image content rather than a generic caption — ideal for extracting precise details (text, counts, attributes, spatial relationships) from photos without building or hosting your own VQA model. At $0.0015 per call with no signup required and pay-per-use crypto billing, it suits low-volume or ad-hoc agent workflows where spinning up a dedicated vision API account isn't justified.

## Known failure modes

- Unsupported image format returns an error — only PNG, JPEG, and WebP are accepted
- Very low-resolution or heavily compressed images may yield vague or incorrect answers
- Questions requiring world knowledge beyond the image content may produce hallucinated or uncertain responses
- Missing 'question' field results in a request validation error
- Payment failure or insufficient USDC balance blocks the call with a 402 response

## How this service works

Chat, embeddings, OCR, speech-to-text, image editing, image understanding (captioning/Q&amp;A), text-to-speech, translation, writing tools, classification tools, developer tools, local utilities, format/checksum validators, encoding &amp; crypto utilities, date/time calculators, geo/coordinate math, math &amp; finance calculators, novelty tools, and business/social writing generators — 179 endpoints in all, across multiple specialized self-hosted models. Pay per call with crypto — no signup — or get an API key.

## Output

A natural-language text answer to the posed question, grounded in the content of the uploaded image — e.g. object identification, count, color, text readout, spatial relationship, or scene description depending on what was asked.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "file": {
   "type": "string",
   "format": "binary",
   "description": "Image file (PNG/JPEG/WebP)"
  },
  "question": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastapi-online-image-q-a-e590c047/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.fastapi.online](https://www.zero.xyz/host/api.fastapi.online/llms.txt)