{"uid":"cap_VzI6hWbO2U0daFq7hPYjK","slug":"model-access-gateway-gpt-5-5-chat-completions-x402-usdc-46135043","name":"Model Access Gateway – GPT-5.5 Chat Completions (x402 USDC)","description":"LLM inference API: OpenAI-compatible chat completions for 136 AI models (Claude, GPT, Gemini, Grok, DeepSeek, Qwen, Kimi, GLM), paid per call in USDC on Base with x402. No account, no API key, automatic refund if the model fails.","url":"https://modelaccessgateway.com/llm/gpt-5.5?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"model":{"type":"string","description":"Optional: fixed by the route (openai/gpt-5.5)"},"tools":{"type":"array"},"stream":{"type":"boolean","description":"true: server-sent events after payment"},"messages":{"type":"array","items":{"type":"object","required":["role"],"properties":{"role":{"enum":["system","user","assistant","tool","developer"],"type":"string"},"content":{"type":["string","array","null"]}}},"minItems":1},"max_tokens":{"type":"integer","maximum":16384,"minimum":1,"description":"Optional, default 4096"},"temperature":{"type":"number","maximum":2,"minimum":0},"response_format":{"type":"object"}}},"responseSchema":{"type":"json","example":{"id":"chatcmpl-7f3c2a91","model":"openai/gpt-5.5","usage":{"total_tokens":10,"prompt_tokens":9,"completion_tokens":1},"object":"chat.completion","choices":[{"index":0,"message":{"role":"assistant","content":"OK"},"finish_reason":"stop"}],"created":1791979200}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.0014","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":"$0.0014/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.0014","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.0014","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_8o4SIzHQSIImGijmQ4aRQ","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.0014","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Runs OpenAI GPT-5.5 chat completions via an OpenAI-compatible API, paid per-call in USDC on Base using the x402 protocol — no account or API key required.","exampleAgentPrompt":"Ask GPT-5.5 to write a professional summary for a software engineer with 10 years of Python experience — pay per call in USDC, no API key needed, and keep the response under 300 tokens.","exampleUseCases":[{"title":"Autonomous agent text generation","prompt":"I need my AI agent to draft a concise product description for a new wireless keyboard — use GPT-5.5, limit the response to 200 tokens, and have it pay per call in USDC so I don't need to manage API keys."},{"title":"Structured JSON output from GPT-5.5","prompt":"Send this customer complaint to GPT-5.5 and ask it to return a JSON object with fields for sentiment, urgency level, and suggested resolution — use response_format to enforce JSON and cap at 512 tokens."},{"title":"Tool-calling agent with GPT-5.5","prompt":"Run a GPT-5.5 chat session where the model can call a weather lookup tool I've defined — pass in the tool schema, set temperature to 0 for consistency, and stream the response back to me."}],"resultDescription":"Returns an OpenAI-compatible chat.completion JSON object containing the assistant's message content, finish reason, model used, and token usage (prompt, completion, total). On streaming, delivers server-sent events. If the model fails, an automatic USDC refund is issued.","failureModes":["Model failure triggers automatic USDC refund — agent receives error response and payment is returned","Insufficient USDC balance causes x402 payment rejection before inference begins","Invalid or missing messages array returns a 400-level validation error","max_tokens exceeding 16384 is rejected at schema validation","Streaming requested but client doesn't handle SSE — incomplete response received"],"whenToPreferThis":"Choose this endpoint when you need GPT-5.5 specifically, want OpenAI-compatible chat completions without managing an OpenAI account or API key, and can pay per-call in USDC via the x402 protocol. Ideal for autonomous AI agents that need anonymous, accountless LLM access with built-in payment and automatic refund on failure. Prefer this over direct OpenAI when operating in a crypto-native or x402-enabled environment.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-18T06:35:21.696Z","isFirstParty":false,"canonicalSlug":"model-access-gateway-gpt-5-5-chat-completions-x402-usdc-46135043"}