--- title: "Untitled" url: https://daily.dev/posts/untitled-rzedwrjwy source_url: https://www.sitepoint.com/claude-sonnet-5-the-developers-guide-to-anthropics-new-default-model type: article source: "SitePoint" published: 2026-07-03T04:25:51.269Z updated: 2026-07-08T18:24:28.558Z tags: ["nodejs", "claude", "agentic-ai"] reading_time: 20 upvotes: 0 comments: 0 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Untitled **[SitePoint](https://daily.dev/sources/sitepoint)** · 20 min read · 0 upvotes · 0 comments ## Summary Claude Sonnet 5 was released on July 15, 2025 as Anthropic's new default model, replacing Sonnet 4 across the API, Claude.ai, and Claude Code CLI. Key improvements include stronger agentic task decomposition (multi-step planning without re-prompting), more reliable tool/function calling with fewer hallucinated parameters, and better coherence on long outputs. The guide covers API integration with Node.js (model ID: claude-sonnet-5-20250715), a full agentic loop implementation with file read/write tools and path traversal protection, Claude Code CLI usage, and a decision matrix comparing Sonnet 5 ($3/$15 per 1M tokens post-Aug 31) vs Opus 4 ($15/$75) vs DeepSeek V3. Introductory pricing of $2/$10 runs until August 31, 2025, after which a 50% increase takes effect. Practical cost mitigation strategies include prompt caching and request batching. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: --- Tags: [#nodejs](https://daily.dev/tags/nodejs), [#claude](https://daily.dev/tags/claude), [#agentic-ai](https://daily.dev/tags/agentic-ai) [View this post on daily.dev](https://daily.dev/posts/untitled-rzedwrjwy)