# FarOut Pay-Per-Call LLM Inference (GPT-5.6-Luna)

> FarOut Pay-Per-Call LLM Inference (GPT-5.6-Luna) 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).

Runs chat completions against GPT-5.6-Luna via a pay-per-call gateway that charges $0.001 USDC on Base per request with no API key or account required.

## Facts

- Endpoint: POST https://farouter.tech/v1/models/gpt-5.6-luna/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-luna-f5638dfb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_A-dyybtK28_cJi8PbmZin

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-luna-f5638dfb -d '<json body>'
```

Example prompt: Using FarOut's pay-per-call gateway with GPT-5.6-Luna, send this message: 'Explain the trade-offs between transformer and Mamba architectures in 3 bullet points.' Use up to 512 output tokens and a temperature of 0.7.

## When to prefer this

Choose this endpoint when you need GPT-5.6-Luna inference without an OpenAI account or prepaid API credits — particularly in autonomous agent pipelines that already handle x402 USDC micropayments on Base. It is ideal for pay-as-you-go usage patterns, serverless or ephemeral agents, or situations where managing API keys is impractical. Prefer alternatives if you need guaranteed OpenAI SLA, direct OpenAI billing, or models not offered by FarOut.

## Known failure modes

- Insufficient USDC balance or failed x402 payment returns a 402 Payment Required error
- Invalid or unsupported model ID returns a 400 Bad Request
- Messages array is empty or malformed, returning a validation error
- Rate limiting or upstream model unavailability returns a 503 or 429
- max_tokens set too low causes truncated or empty completions

## How this service works

Fixed-price chat completions for gpt-5.6-luna on FarOut: flat $0.002 per call (includes up to 4,000 input + 1,000 output tokens). Rate: $0.016/1M input tokens, $0.096/1M output tokens. Pay with USDC on Base using x402. No API key, no account, no prepaid balance.

## Output

An OpenAI-compatible chat completion response containing an assistant message, finish reason, and token usage counts (prompt_tokens and completion_tokens). Streaming SSE chunks are also available when stream is set to true.

## 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-luna-f5638dfb/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)