If you’ve been following Anthropic releases, you know how quickly Claude 3 Opus and, more recently, Claude 3.7 Sonnet became staples for deep reasoning, code generation, and long-context work.

When Claude 3 Opus launched last year, it stunned the industry with long‑context reasoning and elegant prose. Its lighter sibling, Claude 3.7 Sonnet, quickly became the budget darling for everyday tasks. Together, they wrote millions of lines of production code and helped thousands of engineers.

Today Anthropic making the waves again – with new Claude 4 series. Two fresh variants – Claude 4 Opus and Claude 4 Sonnet – arrive with bigger brains, new tools, and the same customer‑friendly token prices that made their predecessors famous. Early benchmarks show Claude 4 Opus coding autonomously for seven straight hours, while Claude 4 Sonnet delivers a 65% drop in “shortcut” errors compared to 3.7 version.

Capabilities: What Exactly Is Claude 4?

Why the hype matters: In Anthropic’s own words, Claude 4 Opus is “the best coding model available today,” posting record‑high scores on SWE‑Bench, HumanEval, and Anthropic’s in‑house "Pass@1‑Extended" benchmark for multi‑file repos. That headline claim doesn't seem to be just marketing – the new architecture introduces deeper reasoning loops, native tool‑calling, and guardrails that make Claude 4 feel less like a chatbot and more like a junior engineer who never gets tired.

Hybrid‑reasoning architecture

A dual‑core brain blends symbolic planning with transformer pattern‑matching. Claude dashes off quick answers when queries are simple, then switches to a slower Extended Thinking pipeline for knotty logic or multi‑step code refactors.

Extended Thinking mode

Flip a toggle (or append #extended to the system prompt) and Claude dedicates up to 8 minutes of GPU time to a single request. That's enough to plan, implement, and unit‑test a short Python script before replying.

200 K‑token context

Still industry‑leading: drop a full novel, three years of Discord logs, or an entire codebase into one prompt. An upgraded attention scheme keeps retrieval latency steady even at maximum window size.

Transparent chain of thought

The new Thinking Summary pane exposes Claude’s reasoning steps so teams can audit logic, spot hallucinations, and fine‑tune prompts.

Native tool calling & secure code execution

Claude 4 now speaks the "tool" schema pioneered by function‑calling LLMs – but adds a built‑in Python sandbox and optional web‑search hook. You can ask it to "write, run, and debug" a snippet in one go, with results streamed back token‑by‑token.

Fine‑grained safety rails

Anthropic ships Claude 4 with policy‑dial sliders (low, medium, high). Toggle them on a per‑request basis to balance creativity with compliance.

With these upgrades Claude 4 isn’t merely faster or bigger. It’s build for autonomous coding agents, large‑scale document synthesis, and any workflow where trust and traceability matter.

Two Generations, Two Price Points

From legacy workhorses to fresh flagships, the lineup now spans four distinct options – giving you clear trade‑offs in cost, context, and capability. Compare at a glance:

How to Get Access to Claude 4

Four easy pathways: Whether you prefer a point‑and‑click web UI, raw API calls, an all‑in‑one writing platform, or managed cloud endpoints, Claude 4 is just a few steps away. Follow the simple, straightfoward guides below.

1. Option The Official Chat (claude.ai)

Best for quick browser sessions:

1. Navigate to claude.ai and sign in (or create a free account).

2. Click the Model selector in the upper‑left corner of the chat window.

3. Pick Claude 4 Sonnet (Free tier) or Claude 4 Opus (Pro, Team, Enterprise).

4. Toggle Extended Thinking if you want extra reasoning time.

5. Enter your prompt and press Enter—Claude will answer in seconds.

2. Direct API Calls

Best for developers, automations & agents:

1. Grab your Anthropic API key from the dashboard.

2. Install the official anthropic Python/TypeScript SDK or use curl.

3. Set the model field to either claude-4-opus-2025-05-22 or claude-4-sonnet-2025-05-22.

4. Send your request (example below) and stream the response:

curl https://api.anthropic.com/v1/messages \
  -H "x-api-key:$ANTHROPIC_API_KEY" \
  -H "anthropic-version:2025-05-22" \
  -d '{"model":"claude-4-opus-2025-05-22","max_tokens":1024,
       "messages":[{"role":"user","content":"Summarize the EU AI Act"}]}'

5. All other parameters – function calls, tools, streaming – remain identical to Claude 3, so upgrades take minutes.

3. WritingMate.ai (new.writingmate.ai)

Best for writers & researchers who want Claude 4 plus 200+ other models:

1. Log in at new.writingmate.ai (roll‑out starts with Pro & Ultimate plans in the coming days).

2. Open an existing document or start a new project.

3. Click the Model menu in the right‑hand sidebar.

4. Select Claude 4 Sonnet or Claude 4 Opus once the toggle appears.

5. Draft, rewrite, or analyze – Claude 4 now works side‑by‑side with GPT o3, Gemini Pro, and other modern AI models. No API keys required to use the service.

4. Cloud Marketplaces (AWS Bedrock & Google Vertex AI)

Best for production workloads on managed infrastructure:

1. AWS: In the console, open Amazon Bedrock → Model access and enable Claude 4 for your account.

2. GCP: In Vertex AI → Model Garden, search for Anthropic Claude 4 and request access.

3. Grant IAM roles and (if needed) request a higher service quota for throughput‑heavy jobs.

4. Call the model via the Bedrock or Vertex SDK using the same parameters shown in the API example above.

5. Track usage and cost in your cloud billing dashboard.

Claude 4 Comparison vs. Other Models

Flagship face‑off: so, let's make a brief face-to-face comparison of Claude 4 versus other popular LLMs.

Claude 4 vs. OpenAI o3

Here’s how the new Opus stacks against OpenAI’s top reasoning model.

Why Opus still wins on cost: despite the higher output price, Opus’ longer “focus time” and stronger coding scores can make it cheaper per task for agentic workflows.

Claude 4 vs. Claude 3

Official Benchmarks from Anthropic

Below is the screenshot that highlights performance differences between Claude 4 and other top reasoning models:

Fresh Toys for Builders from Anthropic

Beyond bigger models: Anthropic also shipped a bundle of features that turn Claude into a full‑blown agent platform:

• Code Execution Tool – secure Python sandbox shipping in the API today.

• IDE extensions – first‑party plug‑ins for JetBrains and VS Code pipe Claude suggestions straight into your editor.

• MCP connector – a persistent socket layer so external agents can whisper tasks to Claude without HTTP latency.

• Files API – upload a PDF or CSV once, reference it across prompts without Base‑64 bloat.

• Web Search – let Claude pull live facts mid‑response when your corpora run dry.

• Prompt Caching (1‑hour TTL) – cache static system prompts for 12× longer, slashing latency and cost for long‑running agents.

Coming Soon to Writingmate

Our engineering team has Claude 4 humming inside the Writingmate.ai staging environment right now. Pro and Ultimate subscribers will see a Claude 4 (beta) toggle appear in their dashboards within the next few days. What it means:

• Sharper outlines and drafts thanks to Sonnet’s improved reasoning.

• One‑click deep‑dive reports powered by Opus’ marathon context window.

• Native handling of large PDFs via the new Files API – no copy‑paste gymnastics will be needed.

Stay tuned to our newsletter for the announcement.

My Five Cents

With Claude 4, Anthropic hasn’t just delivered a faster car; it has bolted on a whole garage of developer gear that lets the model read files, run code, and think for hours without supervision. Pair that with the coming integration inside Writingmate.ai, and the question is no longer “How do I get Claude 4 access?” it’s “What will you build next?”

Useful Links & Readings

• Anthropic — Claude 4 Official Press-release

• Claude 4 Pricing & Limits (API)

• Official Chat UI (claude.ai)

• Anthropic API Quick-Start Guide

• Code Execution Tool Docs

• Files API & Web Search (beta)

• JetBrains IDE Plug-in

• VS Code Extension

• AWS Bedrock — Enabling Claude 4

• Google Vertex AI — Anthropic Models
  
  

Happy prompting and coding, guys!

Artem
Co‑founder & CEO, WritingMate.ai