Software engineer and founder with a background in finance and tech. Currently building aVenture.vc, a platform for researching private companies. Based in San Francisco.
Anthropic just released their next generation of AI models: Claude Opus 4 and Claude Sonnet 4. This is a major update with real improvements for coding, reasoning, and agent workflows.
The Claude 4 family introduces two distinct models with complementary strengths:
Claude Opus 4 is Anthropic's most intelligent model to date and, according to their benchmarks, the world's best coding model. My experience anecdotally more or less confirms this, although Google and OpenAI models have recently come neck-and-neck with Anthropic.
It handles complex, long-running tasks that require thousands of steps and hours of focused effort—useful for AI agents.
Claude Sonnet 4 improves on Sonnet 3.7 with better coding and reasoning and more precise instruction-following. It doesn't match Opus 4 in most areas, but works well for everyday use.
Claude models now lead on several benchmarks:
| Benchmark | Claude Opus 4 | Claude Sonnet 4 | Previous Best |
|---|---|---|---|
| SWE-bench Verified | 72.5% | 72.7% | 67.0% (GPT-4.1) |
| Terminal-bench | 43.2% | 39.6% | 38.0% (GPT-4.1) |
| MMLU | 90.2% | 88.0% | 88.7% (GPT-4.1) |
| TAU-bench | 83.0% | 78.0% | 76.0% (o3) |
Claude Opus 4 can maintain performance over extended periods, at least according to the benchmark results. They cited today a Rakuten validation of this by having Opus 4 run a demanding open-source refactor continuously for 7 hours with sustained performance—something previous models couldn't achieve. If true, this would constitute a significant improvement over the status quo -- I'll be testing this shortly.
Both Claude 4 models are hybrid reasoning models offering two modes:
The extended thinking capability now works with tools like web search, allowing Claude to alternate between reasoning and tool use to improve responses. This helps with research tasks, complex coding problems, and multi-step workflows.
Claude can dynamically decide when to use extended thinking based on task complexity, rather than requiring explicit configuration.
After a successful research preview, Claude Code is now generally available with more capabilities. It lives in your terminal, understands your codebase, and helps you code faster through natural language commands.
Claude Code can:
New IDE integrations for VS Code and JetBrains:
The integrations include:
Cmd+Esc (Mac) or Ctrl+Esc (Windows/Linux) to open Claude Code directly from your editorClaude Code now supports:
GitHub reports that Claude Sonnet 4 "soars in agentic scenarios" and will serve as the base model for the new coding agent in GitHub Copilot.
Claude Code also supports git worktrees, so you can run multiple Claude Code sessions in parallel across different branches of the same repository.
Git worktrees let you check out multiple branches of a repository simultaneously in different directories. With Claude Code, this enables:
To set up a git worktree workflow with Claude Code:
# Create a new worktree for a feature branch
git worktree add ../repo-feature-a feature/a
# In one terminal, run Claude Code in the main worktree
cd /path/to/main/repo
claude-code
# In another terminal, run Claude Code in the feature worktree
cd ../repo-feature-a
claude-code
Anthropic has released four new capabilities on their API for building AI agents:
Both models maintain consistent pricing with previous Opus and Sonnet models:
| Model | Input Tokens | Output Tokens | Context Window | Availability |
|---|---|---|---|---|
| Claude Opus 4 | $15 per million | $75 per million | 200K tokens | Pro, Max, Team, Enterprise |
| Claude Sonnet 4 | $3 per million | $15 per million | 200K tokens | All users (including free) |
Both models are available on:
Claude 4 matters for developers building AI-powered applications:
Sustained performance for complex tasks: The ability to work continuously for hours enables entirely new categories of AI applications.
Improved memory capabilities: When given access to local files, Claude Opus 4 can create and maintain "memory files" to store key information, enabling better long-term task awareness.
Reduced shortcut behavior: Both models are 65% less likely to take shortcuts or exploit loopholes compared to Sonnet 3.7, making them more reliable for autonomous workflows.
Thinking summaries: A new feature that condenses lengthy thought processes, making it easier to understand Claude's reasoning without sacrificing depth.
For developers working on coding assistants, research tools, or autonomous agents, these improvements enable more capable AI applications.
The Claude 4 models can maintain context and stay on task for longer projects—useful across many domains.
Stop hardcoding API keys in MCP configs and AI tool settings. Learn how to use 1Password CLI or Doppler to inject secrets just-in-time for Claude, Cur...
