summary-worldofai-claude-4-opus-sonnet-cline

Claude 4 Sonnet & Opus + Cline FULLY FREE AI Coder

Source: YouTube — WorldofAI, published 2025-05-23 Tools covered: Claude 4 Opus / Sonnet, Cline

Summary

WorldofAI demonstrates Claude 4 Opus and Sonnet (state-of-the-art at the time, with Opus #1 on SWE-bench Verified) running through Cline inside VS Code as a fully free full-stack development stack. Pricing breakdown: Opus at $15/$75 per million tokens (input/output), Sonnet at $3/$15. Two end-to-end builds: a SaaS landing page generated for ~$2.60 in tokens with Sonnet, and a Browserbase-powered autonomous browser agent one-shotted by Opus (full backend + frontend in a single prompt). Calls out free-API workarounds — Requesty and Kilo — for users who want to skip Anthropic billing entirely.

Key facts

• Claude 4 Opus: $15input/$75 output per 1M tokens; #1 SWE-bench Verified at time of recording
• Claude 4 Sonnet: $3input/$15 output per 1M tokens; faster than Opus for real-time work
• Demo cost: SaaS landing page ~$2.60 in Sonnet tokens
• Demo capability: Opus one-shotted a full Browserbase agent (backend + frontend) in a single prompt
• Free-API workarounds: Requesty, Kilo (free-credit gateways for Cline users)

Why it matters

This is a second source on Cline (third overall in the wiki) and the first source that puts a concrete dollar number on a Claude-4-Sonnet-driven full-stack build. The “$2.60 for a landing page” data point is the kind of cost-of-build evidence the SaaS death spiral thesis needs.

The Requesty / Kilo mention is also the first time the wiki has a name for free-credit gateways as a category — distinct from OpenRouter’s pay-as-you-go model. Worth tracking as a sub-pattern of Open-Source Model Integration.

See Also

• Claude — model entity
• Cline — agent harness
• Open-Source Model Integration — the broader cost-routing thread
• Stagehand — Browserbase’s AI browser-automation framework (sibling Browserbase reference)
• WorldofAI