# OpenWeb Ninja — ChatGPT AI Answers API (x402)

> OpenWeb Ninja — ChatGPT AI Answers API (x402) is a paid API for AI agents from x402.openwebninja.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Sends a message to a ChatGPT-powered AI endpoint and returns a conversational answer, optionally with search or study context hints, payable per call via x402 USDC.

## Facts

- Endpoint: POST https://x402.openwebninja.com/ai-answers/chatgpt/chat
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/openweb-ninja-chatgpt-ai-answers-api-x402-c13e2678
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2MPDUUmo02wtEBgZHxsoU

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 openweb-ninja-chatgpt-ai-answers-api-x402-c13e2678 -d '<json body>'
```

Example prompt: Ask ChatGPT what the differences are between supervised and unsupervised machine learning, and give me the answer formatted in markdown with a study-focused explanation.

## When to prefer this

Choose this endpoint when you need ChatGPT-powered AI answers on a pay-per-call basis with no API key or account setup, especially inside agent pipelines that support x402 micropayments. Prefer it over direct OpenAI API calls when you want zero credential management and per-call USDC billing on Base, Polygon, or Arbitrum. The SEARCH and STUDY conversation hints make it particularly useful for research or educational answer generation tasks.

## Known failure modes

- Payment failure if the x402 USDC micropayment is not completed or wallet balance is insufficient
- Invalid or empty message field returns an error
- Unsupported conversation_hint enum value causes a validation error
- Network timeout if the upstream ChatGPT API is slow or unavailable
- Empty or malformed JSON response if the underlying model fails

## How this service works

40+ public web-data, SERP, e-commerce, real-estate, finance and AI-search APIs, payable per call over x402 (USDC on Base, Polygon, Arbitrum). No account or API key required. Most endpoints $0.003; AI-model endpoints $0.005.

## Output

A JSON response containing a ChatGPT-generated text answer to the submitted message, optionally formatted in markdown. The response reflects the selected conversation hint mode (blank for general chat, SEARCH for web-search-style answers, or STUDY for educational explanations).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "debug": {
   "type": "boolean",
   "default": false
  },
  "message": {
   "type": "string"
  },
  "markdown": {
   "type": "boolean",
   "default": true
  },
  "conversation_hint": {
   "enum": [
    "",
    "SEARCH",
    "STUDY"
   ],
   "type": "string",
   "default": ""
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {}
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/openweb-ninja-chatgpt-ai-answers-api-x402-c13e2678/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.openwebninja.com](https://www.zero.xyz/host/x402.openwebninja.com/llms.txt)