# momoAI Chat — Pay-per-call LLM API

> momoAI Chat — Pay-per-call LLM API is a paid API for AI agents from aimomo.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-16).

Sends a chat message array to a hosted LLM and returns a text completion, paying $0.01 USDC per call via x402 on Base.

## Facts

- Endpoint: POST https://aimomo.vercel.app/api/chat
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/momoai-chat-pay-per-call-llm-api-2cf5cbe5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ptKES68xY577uj7DFUupG

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 momoai-chat-pay-per-call-llm-api-2cf5cbe5 -d '<json body>'
```

Example prompt: Use momoAI's pay-per-call chat API to summarize the following article in 3 bullet points, keeping temperature at 0.3 and max_tokens at 300: 'Central banks worldwide are raising interest rates to combat inflation, but economists warn of recession risks...'

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-call LLM API that bills in USDC on Base via the x402 protocol, avoiding subscription commitments. Ideal for AI agents that want to pay only for what they use, for low-volume or bursty workloads, or for pipelines that need programmable crypto-native payments for each LLM call.

## Known failure modes

- Payment not included or insufficient USDC — returns 402 Payment Required
- Invalid messages array format — returns 400 validation error
- Model overloaded or unavailable — returns 503 or timeout
- max_tokens set too high for model context window — truncation or error
- temperature out of valid range — returns 400 validation error

## How this service works

Pay-per-use LLM API. Chat, reasoning, code review, translation, summarization, data extraction, and more. Pay with USDC on Base.

## Output

Returns a JSON object with a 'data' field containing the completion text, model name, token usage breakdown (prompt, completion, total tokens), and finish reason, plus a 'meta' field with price, endpoint, and timestamp, and a top-level 'success' boolean.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "messages"
 ],
 "properties": {
  "messages": {
   "type": "array"
  },
  "max_tokens": {
   "type": "integer"
  },
  "temperature": {
   "type": "number"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "data": {
   "type": "object",
   "properties": {
    "id": {
     "type": "string"
    },
    "model": {
     "type": "string"
    },
    "usage": {
     "type": "object",
     "properties": {
      "total_tokens": {
       "type": "integer"
      },
      "prompt_tokens": {
       "type": "integer"
      },
      "completion_tokens": {
       "type": "integer"
      }
     }
    },
    "content": {
     "type": "string"
    },
    "finish_reason": {
     "type": "string"
    }
   }
  },
  "meta": {
   "type": "object",
   "properties": {
    "model": {
     "type": "string"
    },
    "price": {
     "type": "string"
    },
    "endpoint": {
     "type": "string"
    },
    "timestamp": {
     "type": "string"
    }
   }
  },
  "success": {
   "type": "boolean"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/momoai-chat-pay-per-call-llm-api-2cf5cbe5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from aimomo.vercel.app](https://www.zero.xyz/host/aimomo.vercel.app/llms.txt)