# x402engine Qwen 2.5-72B Instruct LLM

> x402engine Qwen 2.5-72B Instruct LLM is a paid API for AI agents from x402engine.app, paid per call via x402, $0.003898/call, status unknown (last checked 2026-10-12).

Run inference on Alibaba's Qwen 2.5 72B Instruct language model via a pay-per-call HTTP 402 micropayment API

## Facts

- Endpoint: POST https://x402engine.app/api/llm/qwen?utm_source=zero.xyz
- Price: $0.003898/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402engine-qwen-2-5-72b-instruct-llm-93494399
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dYDW0KvVPEUJ1enqUXYmg

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-qwen-2-5-72b-instruct-llm-93494399 -d '<json body>'
```

Example prompt: Ask Qwen 2.5 72B Instruct to explain the difference between supervised and reinforcement learning in three bullet points — pay per call with USDC on Base.

## When to prefer this

Choose this endpoint when you need a high-quality open-weight instruction-following model (72B parameters) without a subscription, API key setup, or monthly commitment — paying only $0.0039 per call in USDC. Prefer Qwen 2.5-72B over smaller models when task complexity demands strong reasoning, coding, or multilingual support. Use over proprietary alternatives when cost predictability per call matters or when building agentic pipelines that need tool/function-calling support at low marginal cost.

## Known failure modes

- Payment not settled — 402 response returned if micropayment fails or USDC balance insufficient
- Invalid messages format — missing required 'messages' array causes schema validation error
- Unsupported parameter — passing top_k or seed to a model that doesn't support it may be silently ignored or error
- Context length exceeded — very long message arrays may exceed the model's context window
- Stream interruption — SSE stream may cut off mid-response on network issues

## 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 response containing the model name (qwen/qwen-2.5-72b-instruct), a choices array with the assistant message (role, content, optional tool_calls), finish_reason (e.g. 'stop'), and a top-level content field. When streaming is enabled, delivers OpenAI-compatible SSE chunks instead.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "bodyType",
    "body",
    "method"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "messages"
     ],
     "properties": {
      "seed": {
       "type": "integer",
       "description": "Model-supported seed; see /docs/llm-capabilities.md."
      },
      "stop": {
       "oneOf": [
        {
         "type": "string"
        },
        {
         "type": "array",
         "items": {
          "type": "string"
         },
         "maxItems": 4
        }
       ],
       "description": "Model-supported stop; see /docs/llm-capabilities.md."
      },
      "min_p": {
       "type": "number",
       "description": "Model-supported min_p; see /docs/llm-capabilities.md."
      },
      "tools": {
       "type": "array",
       "items": {
        "type": "object",
        "required": [
         "function"
        ],
        "properties": {
         "type": {
          "enum": [
           "function"
          ],
          "type": "string"
         },
         "function": {
          "type": "object",
          "properties": {
           "name": {
            "type": "string"
           },
           "strict": {
            "type": "boolean"
           },
           "parameters": {
            "type": "object"
           },
           "description": {
            "type": "string"
           }
          }
         }
        }
       },
       "description": "Client-executed function definitions; return results using role=tool and tool_call_id."
      },
      "top_k": {
       "type": "integer",
       "description": "Model-supported top_k; see /docs/llm-capabilities.md."
      },
      "top_p": {
       "type": "number",
       "description": "Model-supported top_p; see /docs/llm-capabilities.md."
      },
      "stream": {
       "type": "boolean",
       "description": "Return live OpenAI-compatible SSE after payment settlement."
      },
      "messages": {
       "type": "array",
       "items": {
        "type": "object",
        "anyOf": [
         {
          "required": [
           "content"
          ]
         },
         {
          "required": [
           "tool_calls"
          ]
         }
        ],
        "required": [
         "role"
        ],
        "properties": {
         "name": {
          "type": "string"
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "model": "qwen/qwen-2.5-72b-instruct",
  "choices": [
   {
    "index": 0,
    "message": {
     "role": "assistant",
     "content": "Hello!"
    },
    "finish_reason": "stop"
   }
  ],
  "content": "Hello!"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402engine-qwen-2-5-72b-instruct-llm-93494399/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)