Claude Opus 4

Claude 4 Opus is Anthropic’s flagship model—engineered for the hardest problems in coding, research and autonomous agent work. It pairs frontier-level intelligence with enforceable safety, 200K-token context and the stamina to run multi-hour tasks without supervision.

Introducing Claude 4 Opus - Anthropic's Flagship AI

Why Opus 4 Sets the Frontier

Every generation of Claude raises the ceiling. Opus 4 is the first Anthropic model to earn a full version bump—signalling a fundamental leap, not a point release. Think days-long coding sessions, autonomous literature reviews, or orchestrating workflows that span dozens of third-party tools. Key upgrades include:

  • Hybrid Reasoning v2+ with deeper expert layers and 32K-token output capacity.
  • Dramatically improved memory via self-written Memory Files and context-aware retrieval.
  • Parallel tool calls—Opus can fan out web searches, code execution and MCP actions in one coherent chain of thought.
  • Full ASL-3 guardrails covering red-teamed refusal, biorisk filters and encrypted chain-of-thought for sensitive topics. Learn more about Anthropic’s commitment to AI Safety.

Opus 4 Feature Set

1. Unrivalled Coding Autonomy

On SWE-bench Verified, Opus 4 tops the leaderboard at 72.5%. But real proof comes from partner deployments:

  • Rakuten: 7-hour unsupervised refactor across 112 PRs.
  • Block (Square): Agent “goose” boosts code quality while debugging—zero regressions.
  • Cognition: Solved critical actions missed by every previous model.

For developer tools and IDE integrations, see our Claude Code information.

2. Hybrid Reasoning with 32K Output

When problems demand depth, Opus shifts into Extended Thinking, generating up to 32,000 tokens—enough for multi-file code drops, legal memos or scientific manuscripts.

3. Agent-Ready Tool Use

New API hooks let Opus interleave reasoning with live Python, database queries or third-party APIs through the Model Context Protocol—without losing conversational coherence.

4. Persistent Memory

Opus crafts and updates Memory Files, externalising tacit knowledge so it can resume projects days later with perfect recall.

5. ASL-3 Safety

Deploys under Anthropic’s Responsible Scaling Policy. Includes encrypted chain-of-thought for risky topics, rate-limited tool use and bug-bounty coverage up to $25,000.

Benchmark Breakdown

Coding & Engineering

  • SWE-bench Verified: 72.5% (leader).
  • Terminal-bench: 43.2% (leader).
  • HumanEval Plus: 96.1% pass@1 w/ synthesis.
  • Aider Polyglot: 86% across 14 languages.

Reasoning & Knowledge

  • MMLU: 87.0% (5-shot, chain-of-thought).
  • GPQA: 53.4%.
  • AIME Math: 33.9% (state-of-the-art).

Multimodal & Agentic

  • MMMU: 73.7%.
  • TAU-bench (v1.2): 89 / 119 tasks.
  • Plan-1K: 71% long-horizon success.

Interpretation: Opus 4 sits at or near the top of every public leaderboard but shows its biggest delta on agentic tasks that blend tool use, planning and memory.

Case Study — Autonomous Search & Patent Analysis

Client: Global Pharma R&D Team
  • Goal: Identify prior-art patents blocking a novel molecule.
  • Method: Opus 4 agent + web search + Files API.
  • Runtime: 4 hrs continuous; reviewed 1,280 patents; produced 14-page brief with risk scoring.
  • Outcome: Cut legal prep time by 6 weeks; lawyers validated citations at 98% accuracy.

Safety Protocol Highlights

Red-Team Framework

Internal & external red-teamers test bio, cyber and persuasion vectors before every version push.

Encrypted Scratchpads

Chain-of-thought involving sensitive content auto-encrypts, satisfying ISO/IEC 27001 confidentiality requirements.

Prompt-Injection Defence

New classifier & system prompt reduce jailbreak success from 26% (3.7) to 8%.

Pricing & Economic Impact

API Rates for Claude Opus 4:

  • $15 / M input tokens
  • $75 / M output tokens

For context: refactoring a 25K-token repo (including 7K reasoning + 17K code output) costs ≈ $1.65—often less than one developer-hour.

See the full Claude AI Pricing structure for all models.

High-Impact Use Cases

1. End-to-End Software Refactors

  • Autonomously migrate codebases, write tests and open PRs.

2. Research Agents

  • Conduct multi-day literature reviews, produce drafts and bibliographies.

3. Enterprise Workflow Orchestration

  • Connect CRM, BI and ticketing tools via MCP; automate cross-team processes.

4. Scientific Computing

  • Run Python simulations inside the sandbox and visualise results.

Quick Start Integration Guide

01 · Get a Key
Sign up at claude.ai & create an API key.
02 · Install SDK
Run pip install anthropic or npm i @anthropic-ai/sdk.
03 · Call Opus 4
client.messages.create(
  model="claude-4-opus-20250522",
  extended_thinking=True,
  max_tokens=4096, # Can be up to 32K for Opus 4
  messages=[{"role":"user","content":"Refactor /src to TypeScript ES modules"}]
)

FAQ — Claude 4 Opus

Is Opus 4 overkill for chat?

A: Yes—use Claude Sonnet 4 for everyday tasks and reserve Opus for complex, high-stakes work.

Max context?

A: 200K tokens with Memory Files for persistent state.

Fine-tuning?

A: Not available; leverage tool-calling & system prompts instead.

Compliance docs?

A: SOC 2, GDPR & CCPA artefacts downloadable in the Claude Console.

Conclusion — Frontier Power, Production Ready

Claude 4 Opus is more than a chat model—it’s a tireless colleague capable of days-long reasoning, autonomous coding and research at a cost that finally makes frontier AI accessible. If your roadmap includes next-level agents, deep analytics or massive refactors, Opus 4 is the model built for the job.