{"uid":"cap_zLfeSgWJKbTo9et0pyvoE","slug":"watt-chat-completions-qwen3-5-4b-qwen3-1-7b-0-6b-838a90bf","name":"Watt Chat Completions (Qwen3.5 4B / Qwen3 1.7B / 0.6B)","description":"","url":"https://watt.area21.io/v1/chat/completions?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":null,"responseSchema":null,"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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_gmrkiqEYWc1QtQ8VN0KfK","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Runs OpenAI-compatible chat completions using Qwen3 small language models on Watt's own infrastructure, billed per call in USDC via x402.","exampleAgentPrompt":"Using the Watt Qwen3.5 4B model, generate a reply to this customer message: 'Can you explain how compound interest works in simple terms?' — set max_tokens to 300.","exampleUseCases":[{"title":"Lightweight agent reasoning step","prompt":"Use the Qwen3 1.7B model on Watt to summarize this paragraph in two sentences and extract the main topic, keeping it under 150 tokens."},{"title":"Pay-per-call chatbot response","prompt":"I need a friendly customer support reply to 'Where is my order?' — run it through the Watt Qwen3.5 4B model and cap the response at 200 tokens."},{"title":"Automated content drafting pipeline","prompt":"Draft a short product description for 'noise-cancelling wireless headphones' using the Qwen3 0.6B model on Watt, max 250 tokens — I want to pay per call rather than subscribe to a big API."}],"resultDescription":"Returns an OpenAI-compatible chat completion object containing the assistant's generated message, finish reason, and token usage breakdown (prompt tokens, completion tokens, total tokens).","failureModes":["Insufficient USDC balance causes payment failure and 402 response","max_tokens too large relative to available budget","Unsupported model name returns 400 or 422 error","Malformed messages array causes validation error","Rate limiting or capacity issues on Watt's fleet return 429 or 503"],"whenToPreferThis":"Choose this endpoint when you need a lightweight, pay-per-call OpenAI-compatible chat completion API without a monthly subscription, especially when using USDC on-chain payments (x402 protocol) or when specifically needing Qwen3-family small models (0.6B–4B) for cost-efficient inference tasks.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-21T07:19:40.813Z","isFirstParty":false,"canonicalSlug":"watt-chat-completions-qwen3-5-4b-qwen3-1-7b-0-6b-838a90bf"}