# x402engine Longcat-2 LLM API > x402engine Longcat-2 LLM API is a paid API for AI agents from x402engine.app, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14). Runs inference on the Longcat-2 large language model via a pay-per-call HTTP 402 micropayment endpoint ## Facts - Endpoint: POST https://x402engine.app/api/llm/longcat-2 - Price: $0.005/call - Payment: x402 - Status: unknown - Last checked: 2026-09-14 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/x402engine-longcat-2-llm-api-f70f81da - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_OPRFU13h3JbgyRHtIoQHF 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-longcat-2-llm-api-f70f81da -d '' ``` Example prompt: Use the Longcat-2 model to write me a concise executive summary of the following market research report — pay via USDC on Base for the call: [paste report text here]. ## When to prefer this Choose this endpoint when you need pay-per-call access to the Longcat-2 LLM specifically without committing to a subscription, when your agent operates with a crypto wallet on Base/MegaETH/Solana and needs to pay for inference programmatically, or when you want to experiment with Longcat-2 at minimal upfront cost ($0.005 per call). ## Known failure modes - Payment failure if USDC wallet balance is insufficient or the 402 payment header is malformed - Model unavailability or timeout resulting in a 5xx error - Invalid or missing prompt input returning a 400 error - Unsupported content or prompt format causing rejection - Rate limiting if too many concurrent requests are sent ## How this service works 108 production APIs behind HTTP 402 micropayments. 72 LLMs, Kling V3 and Hailuo video generation, image generation, code execution, travel search, web scraping, TTS, and transaction simulation. Pay with USDC on Base, USDm on MegaETH, or USDC on Solana. ## Output Returns generated text from the Longcat-2 LLM model as a completion or chat response, typically including the model output and usage metadata such as token counts. ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402engine-longcat-2-llm-api-f70f81da/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)