Claude 3.7 Sonnet (hybrid reasoning) and Claude Code preview
Anthropic released Claude 3.7 Sonnet, the first hybrid reasoning model able to answer instantly or use visible extended thinking, together with a research preview of Claude Code, an agentic coding tool that runs in the terminal.
Key facts
- Released 24 February 2025
- Extended thinking mode with user-controllable thinking budget via API
- SWE-bench Verified: 62.3% (70.3% with custom scaffold), per Anthropic
- Claude Code launched as a limited research preview; generally available with Claude 4 in May 2025
What happened
Anthropic combined fast responses and deep reasoning in one model and shipped a command-line agent that edits code, runs tests and commits on its own.
Why it matters
Claude Code became a breakout product and a template for terminal coding agents (Codex CLI, Gemini CLI), shifting software development toward agent delegation.
Changelog
- 2026-09-29: created
Related events
- Anthropic releases computer use for Claude 3.5 Sonnet ★★★★
- Anthropic releases Claude Opus 4 and Sonnet 4; Claude Code goes GA ★★★★★
- GitHub Copilot and OpenAI Codex bring LLMs to programming ★★★★
- Andrej Karpathy coins "vibe coding" ★★★
Sources (2)
id: 2025-02-24-claude-3-7-sonnet-claude-code · updated 2026-09-29 · open in the interactive timeline