{"uid":"cap_SW7Pj_rwp4iLz-2sqNghy","slug":"zeno-finance-responses-api-x402-ee54d903","name":"Zeno Finance Responses API (x402)","description":"General-purpose Responses API from api.zeno.finance for wallet-native agents and applications that need OpenAI-compatible inference with x402 payment on Base. Pricing starts at $0.001 and is usage-settled up to a $6 per-request cap. Buyers send prompt or structured input and receive concise JSON with output text, tokens spent, and request cost.","url":"https://api.zeno.finance/v1/responses?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"input":{"type":"string","description":"Prompt or instruction to send to the Responses API."},"model":{"type":"string","description":"Configured model name to run, such as gpt-5.5 or gpt-5.4-pro."},"instructions":{"type":"string","description":"Optional system-style instructions for the response."},"max_output_tokens":{"type":"number","minimum":1,"description":"Maximum number of output tokens to generate."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.016025","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":"$0.016025/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.016025","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.016025","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_-HL6Xhz-7PBhCOUif0Tdp","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.016025","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"OpenAI-compatible Responses API endpoint that accepts a prompt and returns generated text with token usage and cost, settled via x402 micropayment on Base.","exampleAgentPrompt":"Send this prompt to the Zeno Finance Responses API using gpt-5.4-pro and up to 512 output tokens: 'Summarize the key risks of investing in early-stage startups in three bullet points.'","exampleUseCases":[{"title":"Autonomous agent inference with crypto billing","prompt":"Use the Zeno Finance Responses API with gpt-5.5 to answer this question for my agent: 'What are the top three DeFi protocols by TVL right now?' — limit to 300 output tokens."},{"title":"Structured data extraction via LLM","prompt":"Send this instruction to Zeno's Responses API using gpt-5.4-pro: extract the company name, founding year, and CEO from the following text — 'Acme Corp was founded in 2011 by Jane Doe.' Use up to 200 output tokens."},{"title":"Crypto-native chatbot response generation","prompt":"I'm building a wallet-native chatbot — use the Zeno Finance Responses API with gpt-5.5 to generate a friendly reply to this user message: 'How do I stake ETH safely?' Keep it under 400 tokens."}],"resultDescription":"A JSON object containing the generated output text, the number of tokens consumed (input and output), and the cost of the request in USDC. Pricing is usage-settled between $0.001 and $6 per request.","failureModes":["Insufficient USDC balance or x402 payment failure — payment not settled, request rejected","Invalid or unsupported model name — returns error indicating unrecognized model","Prompt exceeds model context window — returns token limit error","max_output_tokens set below minimum (1) — validation error","Rate limiting or provider quota exceeded — 429 or 503 response","Malformed input JSON — 400 bad request"],"whenToPreferThis":"Choose this endpoint when you need OpenAI-compatible text generation with per-request crypto micropayment settlement on Base via x402, especially for wallet-native agents or applications that cannot hold traditional API subscriptions. Prefer it over standard OpenAI direct access when autonomous agent payment without a credit card or API key subscription is required. The Responses API format (vs Chat Completions) is preferable when using structured instructions and single-turn inference patterns.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-15T00:36:40.880Z","isFirstParty":false,"canonicalSlug":"zeno-finance-responses-api-x402-ee54d903"}