{"uid":"cap_Uw5fQqpit5KmLoPpIJc_N","slug":"farout-llm-gateway-pay-per-call-chat-completions-gpt-5-5-48b89a9c","name":"FarOut LLM Gateway – Pay-Per-Call Chat Completions (GPT-5.5)","description":"Fixed-price chat completions for gpt-5.5 on FarOut: flat $0.002 per call (includes up to 4,000 input + 1,000 output tokens). Rate: $0.020/1M input tokens, $0.120/1M output tokens. Pay with USDC on Base using x402. No API key, no account, no prepaid balance.","url":"https://farouter.tech/v1/models/gpt-5.5/chat/completions","method":"POST","headers":{},"bodySchema":{"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)."}}},"responseSchema":{"type":"json","example":{"usage":{"prompt_tokens":6,"completion_tokens":8},"choices":[{"message":{"role":"assistant","content":"Hello! How can I help?"},"finish_reason":"stop"}]}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_uFVl-ezXBIBO0zyoGnE7w","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Runs a chat completion request against GPT-5.5 (or any supported frontier model) with per-call USDC micropayment via x402 — no API key or account required.","exampleAgentPrompt":"Ask GPT-5.5 via FarOut: 'Explain the concept of zero-knowledge proofs in simple terms' — use up to 300 output tokens and pay per call with USDC on Base, no API key needed.","exampleUseCases":[{"title":"On-demand coding assistant for an agent","prompt":"Have the FarOut gateway call DeepSeek V4 and ask it to write a Python function that validates an email address using regex — give it up to 500 tokens to respond, and pay per call so I don't need a subscription."},{"title":"Autonomous agent reasoning step","prompt":"My agent needs to decide which tool to use next — send this system prompt and the last 3 messages to Kimi K3 via FarOut and get back its reasoning, keeping it to 200 tokens max."},{"title":"Frontier model benchmarking without accounts","prompt":"Run the same math word problem through GPT-5.5 and GLM-5.3 on FarOut and compare their answers — pay per request in USDC so I don't have to set up separate API keys for each provider."}],"resultDescription":"Returns an OpenAI-compatible JSON object with a choices array containing the assistant's message and finish_reason, plus a usage object with prompt_tokens and completion_tokens counts.","failureModes":["Payment rejected or insufficient USDC balance — HTTP 402 with payment requirements","Invalid model ID — returns 400 with an error indicating the model is not found","messages array empty or malformed — 400 validation error","max_tokens or max_completion_tokens too low for the requested task — response may be truncated with finish_reason=length","Network or upstream model provider outage — 502 or 503 error","Streaming SSE connection dropped mid-response if stream=true"],"whenToPreferThis":"Choose this endpoint when you need on-demand LLM inference without pre-registering for an API key or maintaining a prepaid balance — ideal for autonomous agents that pay per action using x402 USDC micropayments on Base. It is especially useful when you want to route across multiple frontier models (GPT, Gemini, DeepSeek, GLM, Kimi, MiniMax) through a single OpenAI-compatible interface. Prefer it over direct provider APIs when your agent workflow demands trustless, accountless, per-call payment semantics.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T18:43:33.724Z","isFirstParty":false}