{"uid":"cap_xwDAxu1rokohcm0ZBeQWD","slug":"openai-gpt-5-6-luna-chat-completions-x402-usdc-c554fa8d","name":"OpenAI GPT-5.6 Luna Chat Completions (x402, USDC)","description":"gpt-5.6-luna: OpenAI GPT 5.6 Luna (<=272K input tokens) chat completions, paid per call in USDC. Per 1M tokens in/out: Flex (default) 0.1/0.6, Standard 0.2/1.2, Fast 0.4/2.4; pick with service_tier. Plus $0.0005 (Base) or $0.0005 (Solana) per call; the quote charges input plus 10% of max_tokens. Levels: none, low, medium, high, xhigh (model gpt-5.6-luna:<level>). Empty answers are free. Rates: https://openai.mm.family/x402/pricing","url":"https://openai.mm.family/x402/v1/models/gpt-5.6-luna/chat/completions?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"model":{"enum":["gpt-5.6-luna","gpt-5.6-luna:none","gpt-5.6-luna:low","gpt-5.6-luna:medium","gpt-5.6-luna:high","gpt-5.6-luna:xhigh"],"type":"string"},"tools":{"type":"array"},"stream":{"type":"boolean"},"messages":{"type":"array","items":{"type":"object","required":["role","content"],"properties":{"role":{"type":"string"},"content":{"type":"string"}}}},"max_tokens":{"type":"integer"},"service_tier":{"enum":["flex","default","standard","auto","fast","priority"],"type":"string"},"response_format":{"type":"object"},"reasoning_effort":{"type":"string"}}},"responseSchema":{"type":"json","example":{"id":"chatcmpl-x","model":"gpt-5.6-luna","usage":{"total_tokens":9,"prompt_tokens":8,"completion_tokens":1},"object":"chat.completion","choices":[{"index":0,"message":{"role":"assistant","content":"Hello","refusal":null},"finish_reason":"stop"}],"service_tier":"flex"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_bYS8iIKglYI-d5RVmG9BO","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Runs chat completions against the GPT-5.6-Luna model (up to 272K input tokens) with pay-per-call billing in USDC via the x402 protocol.","exampleAgentPrompt":"Send this conversation to GPT-5.6 Luna with medium reasoning level and flex pricing: system: 'You are a concise assistant', user: 'Explain quantum entanglement in two sentences', and give me back the assistant reply.","exampleUseCases":[{"title":"Agentic reasoning with adjustable depth","prompt":"Use GPT-5.6 Luna at the 'high' reasoning level to analyze this legal contract snippet and tell me what liability clauses are present — keep max_tokens to 512 and use flex tier to save cost."},{"title":"Structured JSON output from chat","prompt":"Call GPT-5.6 Luna with a response_format set to JSON and ask it to extract the product name, price, and SKU from this raw product description: 'Blue Widget XL — SKU 99321, now only $14.99!' — use standard tier for reliability."},{"title":"Tool-calling agent loop","prompt":"Send a message to GPT-5.6 Luna with my tools list attached, asking it to look up the current weather in Tokyo and return a structured tool call — use fast tier so it responds quickly."}],"resultDescription":"Returns a standard OpenAI chat.completion JSON object containing the assistant's message content, finish_reason (stop/tool_calls/length), prompt and completion token counts, the service_tier used, and a unique completion ID. Empty responses (when the model produces no content) are billed at $0.","failureModes":["402 Payment Required — insufficient USDC balance or x402 payment header missing/invalid","400 Bad Request — invalid model name, unsupported service_tier, or malformed messages array","context length exceeded — input tokens surpass the 272K limit for this model variant","rate limiting — too many concurrent requests at the chosen service tier","empty completion returned — model produced no output (billed $0 but no useful result)","timeout — fast/flex tier may deprioritize requests under load causing delayed or dropped responses"],"whenToPreferThis":"Choose this endpoint when you need GPT-5.6 Luna specifically, want pay-per-call USDC billing without an OpenAI subscription, need to tune reasoning depth via model suffix levels (none through xhigh), or are building agents on the x402 payment protocol. Prefer over o3 or o4-mini when you want a balance of reasoning quality and cost (Flex at $0.10/$0.60 per 1M tokens). Use gpt-5.5-long or gpt-6-sol-long siblings for inputs exceeding 272K tokens.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-03T04:37:45.820Z","isFirstParty":false,"canonicalSlug":"openai-gpt-5-6-luna-chat-completions-x402-usdc-c554fa8d"}