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x402engine Claude Opus LLM Endpoint
x402
x402engine Claude Opus LLM Endpoint is a paid API for AI agents from x402engine.app, paid per call via x402, $0.070034/call, status unknown (last checked 2026-10-12).
Sends a chat conversation to Anthropic's Claude Opus model and returns a completion, billed per call via HTTP 402 micropayment in USDC
Price / call$0.070034
Success—
StatusUnknown
How this service works
125 production APIs behind HTTP 402 micropayments. 87 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 an OpenAI-compatible JSON object containing the assistant's message content, the model identifier (e.g. anthropic/claude-opus-4.6), choice index, and finish reason (stop, tool_calls, etc.). When streaming is enabled, returns live SSE chunks in OpenAI format.
Example use cases
Complex multi-step reasoning task
“I need you to work through this tricky logic puzzle step by step and explain your reasoning — use Claude Opus since it's the most capable model for hard problems.”
Agent tool-calling pipeline
“Set up a conversation with Claude Opus where it can call my search_web and get_stock_price functions, then ask it to find the latest earnings news for Apple and pull the current stock price.”
Streaming long-form content generation
“Have Claude Opus write a detailed 1000-word technical blog post about zero-knowledge proofs for a developer audience, and stream the output so I can read it as it's generated.”
Technical details
Endpoint
POSThttps://x402engine.app/api/llm/claude-opus?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need Anthropic's most capable Claude Opus model for complex reasoning, nuanced writing, or difficult tool-calling tasks, and want to pay per call in USDC without managing an Anthropic API key or subscription. Prefer this over cheaper Claude Haiku/Sonnet endpoints when task quality is paramount. Use x402engine's micropayment model when your agent needs on-demand LLM access without upfront commitment.
Side effects
- Payment not settled — 402 returned if USDC payment header is missing or insufficient
- Invalid messages array — 400 error if required 'messages' field is absent or malformed
- Token limit exceeded — model returns finish_reason='length' if context is too long
- Tool call format error — 400 if tool definitions do not match the required function schema
- Streaming connection drop — partial SSE response if network is interrupted mid-stream
- Rate limiting — 429 if too many concurrent calls are made
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"model": "anthropic/claude-opus-4.6",
"choices": [
{
"index": 0,
"message": {
"role": "assistant",
"content": "Hello!"
},
"finish_reason": "stop"
}
],
"content": "Hello!"
}
}Tags
x402
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