# FarOut Pay-Per-Call LLM Inference (GPT-5.6-sol) via x402

> FarOut Pay-Per-Call LLM Inference (GPT-5.6-sol) via x402 is a paid API for AI agents from farouter.tech, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Send a chat/completion request to GPT-5.6-sol (or any of 17 frontier models) and pay per call in USDC on Base via x402 — no API key or account required.

## Facts

- Endpoint: POST https://farouter.tech/v1/models/gpt-5.6-sol/chat/completions
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/farout-pay-per-call-llm-inference-gpt-5-6-sol-via-x402-ae8eb011
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QZTGO3U7WYvKo6BXbA8dB

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 farout-pay-per-call-llm-inference-gpt-5-6-sol-via-x402-ae8eb011 -d '<json body>'
```

Example prompt: Using FarOut's pay-per-call API with GPT-5.6-sol, write me a short Python function that parses a JSON file and extracts all email addresses — set max_tokens to 512 and temperature to 0.2.

## When to prefer this

Choose FarOut when your agent needs to call frontier LLMs without pre-registering an account, storing an API key, or maintaining a prepaid credit balance — ideal for autonomous agents that pay per request in USDC via x402. Prefer this over OpenAI direct when you want crypto-native per-call billing, access to multiple frontier models (GPT, Gemini, DeepSeek, Kimi, GLM, MiniMax) through one endpoint, or when operating in a trustless/permissionless environment where key management is undesirable.

## Known failure modes

- Payment insufficient or x402 transaction rejected — request fails before inference begins
- Model ID not found — returns error if model string doesn't match a supported model from GET /v1/models
- max_tokens or max_completion_tokens exceeds model context limit — inference may be truncated or rejected
- Malformed messages array (missing role or content) — schema validation error
- Streaming (SSE) connection drops mid-response — partial output may be returned
- Rate limiting or upstream model provider outage — temporary 5xx errors

## How this service works

Fixed-price chat completions for gpt-5.6-sol on FarOut: flat $0.005 per call (includes up to 4,000 input + 1,000 output tokens). Rate: $0.380/1M input tokens, $2.280/1M output tokens. Pay with USDC on Base using x402. No API key, no account, no prepaid balance.

## Output

Returns an OpenAI-compatible JSON object with a choices array (each entry has a message with role and content, plus finish_reason) and a usage object showing prompt_tokens and completion_tokens consumed.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "model": {
   "type": "string",
   "description": "Model id from GET /v1/models, e.g. glm-5.3. No provider prefix."
  },
  "stream": {
   "type": "boolean",
   "description": "SSE streaming."
  },
  "messages": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "role",
     "content"
    ],
    "properties": {
     "role": {
      "enum": [
       "system",
       "developer",
       "user",
       "assistant",
       "tool"
      ],
      "type": "string"
     },
     "content": {}
    },
    "additionalProperties": true
   },
   "minItems": 1,
   "description": "Chat messages, [OI]-compatible {role, content}."
  },
  "max_tokens": {
   "type": "integer",
   "minimum": 1,
   "description": "Output token budget. Sets your spending cap; actual usage is what gets settled (true-up)."
  },
  "temperature": {
   "type": "number",
   "maximum": 2,
   "minimum": 0,
   "description": "Sampling temperature."
  },
  "max_completion_tokens": {
   "type": "integer",
   "minimum": 1,
   "description": "Alias of max_tokens (gpt-5.x models)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "usage": {
   "prompt_tokens": 6,
   "completion_tokens": 8
  },
  "choices": [
   {
    "message": {
     "role": "assistant",
     "content": "Hello! How can I help?"
    },
    "finish_reason": "stop"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/farout-pay-per-call-llm-inference-gpt-5-6-sol-via-x402-ae8eb011/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from farouter.tech](https://www.zero.xyz/host/farouter.tech/llms.txt)