{"uid":"cap_hqHhAVqjGvTvfKLT294PR","slug":"zeroreader-gpt-oss-20b-chat-completion-7410569e","name":"ZeroReader GPT-OSS 20B Chat Completion","description":"GPT-OSS 20B (OpenAI) — OpenAI's open-source 20B model.","url":"https://api.zeroreader.com/v1/ai/gpt-oss-20b?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"stream":{"type":"boolean","default":false},"messages":{"type":"array","items":{"type":"object","required":["role","content"],"properties":{"role":{"enum":["system","user","assistant"],"type":"string"},"content":{"type":"string"}}}},"max_tokens":{"type":"integer","default":1024,"maximum":4096},"temperature":{"type":"number","default":0.7,"maximum":2,"minimum":0}}},"responseSchema":{"id":"chatcmpl-example","object":"chat.completion","choices":[{"index":0,"message":{"role":"assistant","content":"I'm doing well!"},"finish_reason":"stop"}]},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_i11kKDu4lEueOtY5mfDAA","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Runs chat completions using OpenAI's open-source 20B language model via a pay-per-call x402 API","exampleAgentPrompt":"Use the GPT-OSS 20B model to answer this question — set temperature to 0.7 and limit the response to 512 tokens: 'What are the key differences between transformer and state-space models?'","exampleUseCases":null,"resultDescription":"Returns a chat.completion object containing the assistant's generated reply, a finish_reason (e.g. 'stop'), a unique completion ID, and message metadata — structured identically to the OpenAI chat completion response format.","failureModes":["Payment not provided or insufficient USDC balance — 402 Payment Required","messages array missing or empty — 400 Bad Request","temperature out of range (>2 or <0) — 422 Validation Error","max_tokens exceeds 4096 — 422 Validation Error","Model overload or upstream inference failure — 503 Service Unavailable","Malformed message role (not system/user/assistant) — 400 Bad Request"],"whenToPreferThis":"Choose this endpoint when you need a mid-size capable open-source model (20B parameters) that balances quality and cost at $0.002/call, and you want OpenAI's open-source architecture rather than Meta's Llama or Mistral. Prefer over GPT-OSS 120B when latency and cost matter more than peak capability, and over smaller models like Llama 3.2 3B when task complexity demands more capacity.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T04:57:49.304Z","isFirstParty":false,"canonicalSlug":"zeroreader-gpt-oss-20b-chat-completion-7410569e"}