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x402engine Qwen3.5 LLM API
x402
x402engine Qwen3.5 LLM API is a paid API for AI agents from x402engine.app, paid per call via x402, $0.00366/call, status unknown (last checked 2026-10-12).
Runs the Qwen 3.5 Plus language model via a pay-per-call HTTP 402 micropayment endpoint, returning OpenAI-compatible chat completions
Price / call$0.00366
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
An OpenAI-compatible JSON object containing the model name, an array of choices each with an assistant message (content and/or tool_calls), a finish_reason ('stop', 'tool_calls', etc.), and a top-level content shortcut. When streaming is enabled, returns SSE chunks in OpenAI streaming format.
Example use cases
Agent tool-use with Qwen3.5
“Send this conversation history to Qwen 3.5 Plus with my get_weather and search_web function definitions, and let it decide which tool to call next.”
Pay-per-call code generation
“Use the Qwen3.5 model to write a Python function that parses JSON logs and groups them by error code — I only want to pay for this one call, no subscription.”
Streaming customer support reply
“Have Qwen 3.5 Plus generate a polite customer support response to this complaint email and stream the output so I can show it word-by-word: 'My order arrived broken and support hasn't replied in 5 days.'”
Technical details
Endpoint
POSThttps://x402engine.app/api/llm/qwen3.5?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need Qwen 3.5 Plus specifically (Alibaba's reasoning-capable mid-tier model) without committing to a subscription, paying only $0.00366 USDC per call via HTTP 402 on Base, MegaETH, or Solana. Prefer it over OpenAI or Anthropic endpoints when cost-per-call matters, when you want a Qwen-family model's multilingual or reasoning strengths, or when your agent already uses OpenAI-compatible message schemas and you want a drop-in alternative with crypto micropayments.
Side effects
- 402 Payment Required if USDC/USDm payment header is missing or insufficient
- Invalid messages array structure returns 400 validation error
- Unsupported parameter for this model variant (e.g. top_k not supported) may be silently ignored or return an error — check /docs/llm-capabilities.md
- Stream flag with incompatible client may result in garbled SSE output
- Rate limiting or model unavailability returns 503
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"model": "qwen/qwen3.5-plus-02-15",
"choices": [
{
"index": 0,
"message": {
"role": "assistant",
"content": "Hello!"
},
"finish_reason": "stop"
}
],
"content": "Hello!"
}
}Tags
x402
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