# NexusAPI AI Caption Generator

> NexusAPI AI Caption Generator is a paid API for AI agents from nexus-api-virid.vercel.app, paid per call via x402, $0.04612/call, status unknown (last checked 2026-10-22).

Generates AI-written captions for images, posts, or content based on a text query or description

## Facts

- Endpoint: POST https://nexus-api-virid.vercel.app/api/ai/caption?utm_source=zero.xyz
- Price: $0.04612/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nexusapi-ai-caption-generator-5328d403
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZRVuBec1C-dsEhj3WVSHq

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 nexusapi-ai-caption-generator-5328d403 -d '<json body>'
```

Example prompt: Can you generate a catchy, engaging caption for my photo of a sunset over the ocean — something that would work well on Instagram?

## When to prefer this

Choose this endpoint when you need quick, affordable AI-generated captions for images, social posts, or product descriptions without setting up API keys. At $0.046 per call with pay-per-use USDC billing, it is suitable for low-to-medium volume caption generation tasks integrated into agent workflows.

## Known failure modes

- Empty or missing query parameter returns an error response
- Overly vague queries may produce generic or low-quality captions
- Rate limiting or payment failures if USDC balance is insufficient
- Service unavailability returns a 5xx error from the Vercel deployment
- Very long or complex queries may produce truncated or incomplete captions

## How this service works

Crypto, AI, Social Media, Finance, Weather, Tools &amp; more. Pay per call in USDC on Base. No API keys.

## Output

Returns an AI-generated caption or descriptive text based on the input query or content description, suitable for use on social media, e-commerce listings, or other content platforms.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "query": {
   "type": "string",
   "description": "Search query or input parameter"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "description": "API response data"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nexusapi-ai-caption-generator-5328d403/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from nexus-api-virid.vercel.app](https://www.zero.xyz/host/nexus-api-virid.vercel.app/llms.txt)