{"uid":"cap_t3vUTZRUibtn9b-EahQKm","slug":"gpt-5-5-x402-chat-completions-gateway-7569a68c","name":"GPT-5.5 x402 Chat Completions Gateway","description":"Low-cost OpenAI-compatible GPT-5.5 chat completion for AI agents, apps, and scripts. Pay up to $0.004 per request with x402 USDC on Base. Exact fixed-price and upto usage-based payment are both accepted when clients support them. Public paid calls are limited to 1500 input characters and 128 output tokens for predictable cost.","url":"https://gpt55.558686.xyz/v1/chat/completions?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"pathParams":{"type":"object","additionalProperties":true},"queryParams":{"type":"object","properties":{"q":{"type":"string"},"input":{"type":"string"},"model":{"enum":["gpt-5.6-sol","gpt-5.6","gpt-5.6-terra","gpt-5.5"],"type":"string"},"prompt":{"type":"string"},"system":{"type":"string"},"message":{"type":"string"},"max_tokens":{"type":"integer","maximum":128000,"minimum":1},"system_prompt":{"type":"string"},"max_output_tokens":{"type":"integer","maximum":128000,"minimum":1}},"additionalProperties":true}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","required":["id","object","model","choices"],"properties":{"id":{"type":"string"},"model":{"type":"string"},"usage":{"type":"object"},"object":{"type":"string"},"choices":{"type":"array"}},"additionalProperties":true}}}}},"responseSchema":{"type":"json","example":{"id":"chatcmpl_example","model":"gpt-5.5","usage":{"total_tokens":44,"prompt_tokens":32,"completion_tokens":12},"object":"chat.completion","choices":[{"index":0,"message":{"role":"assistant","content":"A concise answer from GPT-5.5."},"finish_reason":"stop"}]}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.00293","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","requiresHandshake":false,"reviewCount":1,"rating":{"score":"1.00","successRate":"0.50","reviews":1,"stars":"5.0","state":"rated"},"availabilityStatus":"down","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.00293/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.099995","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.099995","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_BR7U_2z8Qc_qE9HN3QegZ","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.099995","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Provides OpenAI-compatible GPT-5.5 chat completions via a pay-per-call GET endpoint using x402 USDC micropayments on Base","exampleAgentPrompt":"Ask GPT-5.5 via the x402 micropayment gateway: using gpt-5.5 model with a system prompt of 'You are a helpful assistant' and up to 150 output tokens, answer this question — what are the three laws of thermodynamics?","exampleUseCases":null,"resultDescription":"Returns an OpenAI-compatible chat.completion JSON object containing the assistant's text reply, model name, a unique completion ID, finish reason (e.g. 'stop'), and token usage stats (prompt tokens, completion tokens, total tokens).","failureModes":["Payment not included or insufficient USDC via x402 — returns 402 Payment Required","max_tokens exceeds 192 — rejected by schema validation","Missing required input/prompt parameter — returns error or empty response","Model enum value other than 'gpt-5.5' not accepted","Rate limiting or upstream OpenAI API failure — service unavailable"],"whenToPreferThis":"Choose this endpoint when you need GPT-5.5 chat completions on a true pay-per-call basis with no subscription, especially in agentic or automated pipelines that use x402 USDC micropayments on Base. Ideal for low-volume or sporadic usage where a $0.0001 per call cost is acceptable and no OpenAI account is required. Prefer over direct OpenAI API when you want crypto-native payment rails.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":2,"lastUsedAt":"2026-07-11T21:21:53.067Z","lastSuccessfullyRanAt":"2026-07-11T18:39:27.071Z","lastHealthCheckAt":"2026-10-12T22:28:00.175Z","isFirstParty":false,"canonicalSlug":"gpt-5-5-x402-chat-completions-gateway-7569a68c"}