{"uid":"cap_FTjxrRA1pcTi1gjsiM2Ou","slug":"x402engine-gpt-6-luna-llm-api-9ff64cd0","name":"x402engine GPT-6 Luna LLM API","description":"x402engine — GPT-6 Luna is the fast, cost-efficient model in OpenAI's GPT-6 series, positioned below GPT-6 Sol. It is suited for high-volume and latency-sensitive workloads such as chat, classification, and lightweight agentic...","url":"https://x402engine.app/api/llm/gpt-6-luna?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"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."},"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."},"stream":{"type":"boolean","description":"Return live OpenAI-compatible SSE after payment settlement."},"plugins":{"type":"array","items":{"type":"object","required":["pdf"],"properties":{"id":{"enum":["file-parser"],"type":"string"},"pdf":{"type":"object","properties":{"engine":{"enum":["native"],"type":"string"}}}}},"description":"Optional native PDF parser only; automatically enabled for file inputs."},"messages":{"type":"array","items":{"type":"object","anyOf":[{"required":["content"]},{"required":["tool_calls"]}],"required":["role"],"properties":{"name":{"type":"string"},"role":{"enum":["system","developer","user","assistant","tool"],"type":"string"},"content":{"oneOf":[{"type":"string"},{"type":"null"},{"type":"array","items":{"type":"object","required":["type"],"properties":{"type":{"enum":["text","file","image_url"],"type":"string"}},"additionalProperties":true},"maxItems":100,"minItems":1}]},"refusal":{"type":["string","null"]},"reasoning":{"type":"string"},"tool_calls":{"type":"array","items":{"type":"object"}},"annotations":{"type":"array","items":{"type":"object"}},"tool_call_id":{"type":"string"},"cache_control":{"type":"object"},"reasoning_details":{"type":"array","items":{"type":"object"}}},"additionalProperties":false},"maxItems":100,"minItems":1,"description":"Text or model-supported multimodal messages; assistant tool calls may have null content"},"reasoning":{"type":"object","description":"Model-supported reasoning; see /docs/llm-capabilities.md."},"verbosity":{"type":"string","description":"Model-supported verbosity; see /docs/llm-capabilities.md."},"max_tokens":{"type":"integer","example":1024,"description":"Total output budget, including reasoning. Use this or max_completion_tokens."},"tool_choice":{"oneOf":[{"enum":["auto","none","required"],"type":"string"},{"type":"object"}],"description":"Model-supported tool_choice; see /docs/llm-capabilities.md."},"stream_options":{"type":"object","description":"Optional include_usage boolean; usage is always requested upstream."},"response_format":{"type":"object","description":"Model-supported response_format; see /docs/llm-capabilities.md."},"reasoning_effort":{"type":"string","description":"Model-supported reasoning_effort; see /docs/llm-capabilities.md."},"include_reasoning":{"type":"boolean","description":"Model-supported include_reasoning; see /docs/llm-capabilities.md."},"max_completion_tokens":{"type":"integer","description":"Alias for total output budget; bounded by model maxOutputTokens."}},"additionalProperties":false},"type":{"type":"string","const":"http"},"method":{"enum":["POST"],"type":"string"},"bodyType":{"enum":["json","form-data","text"],"type":"string"}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","required":["choices","content"],"properties":{"model":{"type":"string"},"usage":{"type":"object","description":"Provider token and usage accounting, when returned."},"choices":{"type":"array","items":{"type":"object","properties":{"index":{"type":"integer"},"message":{"type":"object","properties":{"role":{"type":"string"},"content":{"type":["string","null"]},"tool_calls":{"type":"array","items":{"type":"object"}}}},"finish_reason":{"type":["string","null"]}}}},"content":{"type":"string","description":"Convenience copy of the first assistant message's text."}}}}}}},"responseSchema":{"type":"json","example":{"model":"openai/gpt-6-luna","choices":[{"index":0,"message":{"role":"assistant","content":"Hello!"},"finish_reason":"stop"}],"content":"Hello!"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003144","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"registry","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":"$0.003144/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003144","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003144","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_2gHGlWBcD42lY5caTWyAZ","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003144","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Provides pay-per-call access to OpenAI's GPT-6 Luna model for chat, classification, and lightweight agentic tasks via HTTP 402 micropayments","exampleAgentPrompt":"Send these messages to GPT-6 Luna and get a response: system says 'You are a helpful assistant', user asks 'What are three creative names for a coffee shop that focuses on sustainability?'","exampleUseCases":[{"title":"High-volume customer support triage","prompt":"Use GPT-6 Luna to classify this support ticket as billing, technical, or general inquiry, then draft a short reply: 'I was charged twice for my subscription last week and can't log into my account.'"},{"title":"Agentic tool-calling workflow","prompt":"Send this conversation to GPT-6 Luna with a get_weather function tool defined, user message is 'What's the weather like in Tokyo right now?' — let it decide whether to call the tool."},{"title":"Streaming chat completion for live UI","prompt":"Stream a GPT-6 Luna response to this user message so I can display it token-by-token: 'Explain how transformer attention works in simple terms, in about 3 paragraphs.'"}],"resultDescription":"Returns an OpenAI-compatible chat completion JSON object with the model name ('openai/gpt-6-luna'), a choices array containing the assistant message with role and content, a finish_reason (e.g. 'stop'), and a top-level 'content' field with the response text. Supports streaming (SSE) and tool call responses.","failureModes":["Payment not settled — 402 response if USDC micropayment fails or is insufficient","Invalid messages array — missing required 'role' or 'content'/'tool_calls' fields returns validation error","Unsupported model capability — requesting features not supported by GPT-6 Luna returns error","Stream requested but client doesn't handle SSE — partial or broken response","Tool call format malformed — incorrect function definition schema causes rejection","Rate limiting or overload — service may return 429 or 503 during high demand"],"whenToPreferThis":"Choose this endpoint when you need fast, cost-efficient LLM inference at scale with pay-per-call pricing (no subscription required), particularly for chat, text classification, or lightweight agentic tool-calling tasks. Prefer it over heavier GPT-6 Sol-tier models when latency and per-call cost are priorities. Best suited for high-volume agent pipelines where you want OpenAI-compatible API responses without managing API keys or subscriptions.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-12T18:47:49.071Z","isFirstParty":false,"canonicalSlug":"x402engine-gpt-6-luna-llm-api-9ff64cd0"}