{"uid":"cap_M0Rf279wQ2Vs2A8OLZaZp","slug":"singit-ask-claude-sonnet-5-5-4e888760","name":"SingIt Ask: Claude Sonnet 5.5","description":"SingIt Ask: Claude Sonnet 5.5 (Anthropic) chat completions with no API key or account, OpenAI-compatible. Anthropic's mid-sized Claude model: everyday coding, writing and analysis at a lower cost than Opus. Call it when an agent needs Claude Sonnet 5.5 specifically.","url":"https://ask.singitai.app/v1/chat/claude-sonnet-5.5?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"model":{"type":"string","examples":["deepseek-v4.1-flash","claude-opus-5.5","gpt-5.5","gemini-3.1-pro"],"description":"Any model id from GET /v1/models; the ceiling follows its price. Omit for the default model."},"stream":{"enum":[false],"type":"boolean","description":"Streaming is not offered."},"messages":{"type":"array","items":{"type":"object","required":["role","content"],"properties":{"role":{"enum":["system","user","assistant"],"type":"string"},"content":{"type":"string","description":"Plain text; all messages together under 24000 characters."}}},"maxItems":40,"minItems":1,"description":"The conversation, oldest first."},"max_tokens":{"type":"integer","default":800,"maximum":1200,"minimum":1,"description":"The longest answer, in tokens. The payment ceiling grows with it; the charge follows what was used."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.0015","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":"$0.007773/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.007773","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.007773","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_Orqfg8qZqWuJsQG9Z8cr6","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.007773","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Provides OpenAI-compatible chat completions using Anthropic's Claude Sonnet 5.5 model, paid per call in USDC with no API key required.","exampleAgentPrompt":"Ask Claude Sonnet 5.5 to review this Python function for bugs and suggest improvements — keep the answer under 800 tokens: [paste function here].","exampleUseCases":[{"title":"Automated code review assistant","prompt":"Use Claude Sonnet 5.5 to review this JavaScript async function and explain any issues it might have — please keep the response under 900 tokens."},{"title":"Draft professional email reply","prompt":"Have Claude Sonnet 5.5 write a polite but firm reply to this vendor email declining their offer, keeping the tone professional and the response under 600 tokens."},{"title":"Summarize and analyze a document","prompt":"Ask Claude Sonnet 5.5 to summarize the key points of this meeting transcript and identify any action items, in under 1000 tokens."}],"resultDescription":"A JSON chat completion response in OpenAI-compatible format containing the assistant's text reply generated by Claude Sonnet 5.5, with token usage metadata. Streaming is not supported; the full response is returned at once.","failureModes":["Payment failure if USDC balance is insufficient for the x402 transaction","Input exceeds 24000 character limit across all messages, resulting in rejection","max_tokens set above 1200 causes validation error","Empty or malformed messages array returns an error","Model ID provided does not match a supported model on the platform"],"whenToPreferThis":"Choose this endpoint when you specifically need Anthropic's Claude Sonnet 5.5 model (mid-tier capability, lower cost than Opus) and want to avoid setting up an Anthropic API account. Ideal for agents that need pay-per-call USDC billing via x402 with OpenAI-compatible request format. Prefer over Claude Haiku when higher reasoning quality is needed, and over Claude Opus when cost is a concern.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T19:05:50.651Z","isFirstParty":false,"canonicalSlug":"singit-ask-claude-sonnet-5-5-4e888760"}