# Image Caption Generator (Single Sentence)

> Image Caption Generator (Single Sentence) is a paid API for AI agents from manyfish-seller.redcliff-d7368db1.westus2.azurecontainerapps.io, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-14).

Generates one descriptive English sentence summarizing the content of a supplied image (JPEG or PNG, base64-encoded).

## Facts

- Endpoint: POST https://manyfish-seller.redcliff-d7368db1.westus2.azurecontainerapps.io/api/v1/image/caption
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/image-caption-generator-single-sentence-ad47182a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_h8no7xkhXo3QIzhvMZmWn

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 image-caption-generator-single-sentence-ad47182a -d '<json body>'
```

Example prompt: Can you generate a one-sentence English caption describing what's in this JPEG image? Here's the base64-encoded image data: [base64string]

## When to prefer this

Choose this endpoint when you need a concise, single-sentence natural language caption for an image and don't need additional metadata like bounding boxes, visual tags, or detected objects. For richer analysis including tags and object locations, prefer the sibling endpoint that returns a caption plus visual tags and objects. Best suited for alt-text generation, content logging, or lightweight image summarization pipelines.

## Known failure modes

- Invalid or malformed base64 string returns a validation error
- Unsupported content type (e.g. image/gif or image/webp) rejected — only image/jpeg and image/png accepted
- Base64 payload exceeding ~13.9 MB max length is rejected
- Corrupt or undecodable image binary returns an error
- Payment failure or missing x402 payment header returns 402 response

## How this service works

Generate one English sentence describing a supplied image.

## Output

A single English sentence that describes the visual content of the supplied image, returned as a text string.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "contentType": {
   "enum": [
    "image/jpeg",
    "image/png"
   ]
  },
  "imageBase64": {
   "type": "string",
   "pattern": "^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$",
   "maxLength": 13981016,
   "minLength": 8
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "image": {
   "width": 200,
   "height": 120,
   "contentType": "image/png"
  },
  "caption": {
   "text": "A red circle and the word hello on a white background.",
   "confidence": 0.92
  },
  "language": "en"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/image-caption-generator-single-sentence-ad47182a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from manyfish-seller.redcliff-d7368db1.westus2.azurecontainerapps.io](https://www.zero.xyz/host/manyfish-seller.redcliff-d7368db1.westus2.azurecontainerapps.io/llms.txt)