# imgnAI Katana API – Text Completion (qnaifu)

> imgnAI Katana API – Text Completion (qnaifu) is a paid API for AI agents from kat.imgnai.com, paid per call via x402, $0.052/call, status unknown (last checked 2026-09-14).

Pay-per-call text/chat completion endpoint supporting frontier LLMs (GPT 5.5, Opus 4.8, Nano Banana 2, Google Omni) via an OpenAI-compatible messages interface

## Facts

- Endpoint: POST https://kat.imgnai.com/v1/text/qnaifu
- Price: $0.052/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/imgnai-katana-api-text-completion-qnaifu-ca6fc596
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YQlT0rUqNI8I_kzZtDILL

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 imgnai-katana-api-text-completion-qnaifu-ca6fc596 -d '<json body>'
```

Example prompt: Using the Katana qnaifu endpoint, send this conversation to a frontier model — system: 'You are a concise assistant', user: 'Explain the concept of zero-knowledge proofs in 3 sentences' — keep max_tokens to 200 and temperature at 0.7.

## When to prefer this

Choose this endpoint when you need a pay-per-call, no-subscription LLM completion compatible with the OpenAI messages format, especially in agentic pipelines using x402 crypto micropayments (USDC) or when you want access to imgnAI's proprietary models (Nano Banana 2, Happy Horse) alongside frontier models at $0.054 per call.

## Known failure modes

- Payment not attached or insufficient USDC — 402 Payment Required
- messages array missing or empty — 400 Bad Request
- Model overloaded or unavailable — 503 Service Unavailable
- max_tokens exceeds model context limit — 400 or truncated response
- Invalid temperature value outside 0–2 range — 422 Unprocessable Entity

## How this service works

Pay-per-call AI gateway: Frontier/SOTA LLM, Image, and Video models - and proprietary low-cost imgnAI models. Includes GPT 5.5, Opus 4.8, GPT Image 2, Nano Banana 2, Seedance 2.0, Happy Horse, and Google Omni. Fully compatible with OpenAPI, HermesOS, and OpenClaw.

## Output

Returns an OpenAI-compatible response object containing one or more completion choices (each with a message and finish reason), plus a usage object detailing prompt and completion token counts.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "messages"
 ],
 "properties": {
  "messages": {
   "type": "array"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/imgnai-katana-api-text-completion-qnaifu-ca6fc596/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from kat.imgnai.com](https://www.zero.xyz/host/kat.imgnai.com/llms.txt)