# x402engine GPT-5.2 LLM API

> x402engine GPT-5.2 LLM API is a paid API for AI agents from x402engine.app, paid per call via x402, $0.035179/call, status unknown (last checked 2026-10-02).

Provides pay-per-call access to OpenAI's GPT-5.2 flagship model with top-tier reasoning, coding, and multimodal capabilities via HTTP 402 micropayments

## Facts

- Endpoint: POST https://x402engine.app/api/llm/gpt-5.2?utm_source=zero.xyz
- Price: $0.035179/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402engine-gpt-5-2-llm-api-4c53b11c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_BynknWIR0fe3HhFhsp2E1

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 x402engine-gpt-5-2-llm-api-4c53b11c -d '<json body>'
```

Example prompt: Use GPT-5.2 to analyze this complex Python codebase and suggest refactoring improvements — specifically focusing on reducing cyclomatic complexity and improving readability across the main module.

## When to prefer this

Choose this endpoint when you need OpenAI's most capable GPT-5.2 model with no subscription or API key setup, paying only per call via USDC micropayments. Ideal for AI agents that need occasional high-quality reasoning, coding, or multimodal analysis without committing to a monthly plan. Prefer this over GPT-4 or Claude endpoints when GPT-5.2's top-tier reasoning or specific OpenAI model behavior is required.

## Known failure modes

- Payment not included or insufficient USDC — returns HTTP 402 with payment required details
- Invalid or malformed message format — returns 400 with schema validation error
- Rate limit or capacity exceeded — returns 429 or 503
- Prompt triggers content policy — returns refusal or 400
- Network timeout on long-form generation — returns 504 or incomplete response

## How this service works

OpenAI's latest flagship model — top-tier reasoning, coding, and multimodal capabilities

## Output

Returns the model's generated text response, which may include reasoning chains, code blocks, structured analysis, or conversational replies depending on the prompt. Response follows standard OpenAI chat completion format with choices, token usage, and finish reason.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402engine-gpt-5-2-llm-api-4c53b11c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402engine.app](https://www.zero.xyz/host/x402engine.app/llms.txt)