A Complete Breakdown of Claude 4’s Core Features – How Close Are We to Programmer Unemployment?

Core Features

Flagship Models

Claude 4 is released in two sizes: Opus (large) and Sonnet (medium). Anthropic’s naming scheme uses Haiku for small, Sonnet for medium, and Opus for large. The previous flagship, Claude 3, launched in March 2024; Sonnet continues from Claude 3.7.

Hybrid Inference

Claude 4, like Claude 3.7, is a hybrid‑inference model. It adds selectable inference length and optional thought‑summary output, comparable to Gemini 2.5 Pro 0520.

Pricing

Sonnet pricing remains the same as Claude 3.7. Opus costs 5–6 times more: $15 per million input tokens and $18.75 per million output tokens.

Context Window and Performance

Claude 4 provides a 200 K token context window, exceeding the typical 128 K limit. It targets AI‑assisted programming and AI‑agent development. Prior to release, Claude 3.7 was the top‑performing model for both tasks. Cursor statistics show >80 % of developers prefer Claude 3.7 for coding, and projects such as Manus and Suna use it as the base model.

MCP Technology

Anthropic’s MCP (Model‑Controlled Programming) technology enables seamless tool‑calling while the model continues reasoning, improving tool‑use accuracy. Relevant tutorials are listed in the references.

Evaluation

Company Feedback

Manus reports Claude 4 handles complex instructions and generates polished front‑end code. UK AI firm iGent observed code‑navigation error rate drop from 20 % to near‑zero. Augmented Code and Sourcegraph described a qualitative leap in code quality, naming Claude 4 their preferred programming model.

User Tests

Independent users generated complete front‑end pages, a Tetris game, and 3D scene designs from single prompts, with impressive runtime results.

Ecosystem Enhancements

Programming Agent

Anthropic released “Claude Code”, an open‑source command‑line programming agent comparable to OpenAI Codex. It can read an entire local project, run tests, push code to GitHub, and be embedded in custom agent interfaces.

Microsoft’s Copilot Coding Agent fully integrates Claude 4, allowing @Claude 4 mentions in any GitHub issue or pull request to invoke the model.

AI‑Agent API Upgrade

The Anthropic API, previously chat‑only, now includes four new features for agent development:

Code Execution – interpreter that observes runtime results and allows manual adjustments, surpassing OpenAI’s interpreter.

RAG Document Retrieval – high‑precision local‑document search.

Extended Cache Tool – provides up to one hour of persistent memory for agents (demonstrated with a Pokémon‑playing example).

MCP Connector – minimal configuration that lets Claude models access a wide range of MCP tools; Anthropic’s integration code is notably concise.

Combined with existing computer‑use and web‑search capabilities, the upgraded API forms a complete development toolkit for Claude 4.

Long‑Running Tasks

Claude 4 can sustain a 7‑hour programming or agent task without degradation.

References

Theory + code guide to MCP: https://mp.weixin.qq.com/s?__biz=Mzk3NTA2OTMxNQ==∣=2247484021&idx=1&sn=c749ce86e33fd64fb1a5b365073af05e

MCP Http SSE mode weather‑assistant demo: https://mp.weixin.qq.com/s?__biz=Mzk3NTA2OTMxNQ==∣=2247484042&idx=1&sn=8d70239dd5dbb4ec79743e0216426a27

Streamable HTTP MCP server tutorial: https://mp.weixin.qq.com/s?__biz=Mzk3NTA2OTMxNQ==∣=2247484222&idx=1&sn=f5e179f9270463cfd421aaea44f64b9c