Claude Opus 4.5 is positioned as Anthropic’s most capable general-purpose model to date, with a particular focus on complex software engineering, advanced reasoning, and multi-step agent behavior. It is available via Anthropic’s apps, the API, and major cloud platforms under the model name claude-opus-4-5-20251101, with pricing set to make “Opus-level” performance accessible to a broader range of users and enterprises.
State-of-the-Art Coding and Agentic Capabilities
The model is tuned to excel on real-world software engineering benchmarks, including challenging end-to-end coding and debugging tasks that mirror production scenarios. Testers and early customers report that Opus 4.5 handles ambiguous requirements, reasons through tradeoffs, and identifies fixes for multi-system bugs with minimal hand-holding, often succeeding on tasks that were previously out of reach for Sonnet 4.5.
Performance on Key Benchmarks
Claude Opus 4.5 demonstrates leading performance across a wide range of benchmarks, including SWE-bench Multilingual and other coding, reasoning, and browsing evaluations. In internal tests, it produces higher-quality code across multiple programming languages and shows strong results on agentic benchmarks like τ2-bench, where it can discover creative, policy-compliant strategies that go beyond the expected “correct” answer.
Real-World Problem Solving in Complex Workflows
One highlight of Opus 4.5 is its ability to navigate intricate procedural constraints in multi-step tasks, such as customer support scenarios with strict policy rules. In such settings, the model can reason through edge cases, identify allowable sequences of actions, and propose solutions that remain within policy while still resolving user issues, illustrating more human-like problem-solving.
Deep Research, Reasoning, and Everyday Tasks
Beyond engineering, Opus 4.5 shows improvements in vision, mathematics, and research-oriented workflows, handling longer, more nuanced projects with fewer errors and less backtracking. It is also tuned for practical office tasks such as working with slides, spreadsheets, and structured documents, making it a strong fit for knowledge workers who need an AI partner across tools.
Advancements in Safety and Robust Alignment
Anthropic describes Claude Opus 4.5 as its most robustly aligned model so far, with significant work invested in reducing “concerning behavior” across a wide spectrum of misuse and misalignment scenarios. The model has undergone extensive safety testing, including evaluations for cooperation with malicious users and undesirable autonomous behaviors, and shows strong resistance to powerful prompt injection attacks.
Resilience to Prompt Injection
Independent red-teaming and specialized evaluations indicate that Opus 4.5 is harder to trick with sophisticated prompt injection attacks than earlier generations and many competing frontier models. This increased robustness is meant to support critical, high-stakes use cases where models may be exposed to untrusted content, such as email, web pages, or shared documents.
New Controls on the Claude Developer Platform
Alongside Opus 4.5, Anthropic has upgraded its developer platform with features that give teams finer control over cost, latency, and depth of reasoning. A new “effort” parameter lets developers choose between faster, cheaper outputs or more thorough, higher-capability reasoning for the same model, depending on the requirements of each task.
Effort, Context, Memory, and Tool Use
At medium effort levels, Opus 4.5 can match Sonnet 4.5’s best performance on challenging benchmarks like SWE-bench Verified while using significantly fewer output tokens; at maximum effort, it surpasses Sonnet’s scores while still being more token-efficient. Combined with features like context compaction, advanced tool use, context management, and long-term memory, the platform enables Opus 4.5 to run longer, coordinate subagents, and tackle deep research tasks with notable gains in accuracy.
Multi-Agent Systems and Long-Running Agents
Opus 4.5 is particularly effective at orchestrating teams of subagents, making it suitable for complex multi-agent systems that require coordination, planning, and persistent state. These capabilities are supported by longer-running agents, improved context tools, and memory features that allow the model to track projects over time while minimizing manual intervention.
Developer Experience and Composability
Anthropic is evolving the Claude Developer Platform toward a more composable architecture, giving builders granular control over efficiency, tool-usage strategies, and how context is managed or compacted. This approach enables bespoke solutions where Opus 4.5 acts as the reasoning core inside tailored workflows for coding, research, automation, or customer support.
Product Updates: Claude Code, Desktop, Chrome, and Excel
Across Anthropic’s product suite, Opus 4.5 powers a new generation of features that showcase its strengths in planning, coding, and interacting with external tools. Claude Code now offers a more capable Plan Mode that asks clarifying questions, generates a structured plan.md, and then executes more precisely against that plan.
Desktop, Browser, and Spreadsheet Integrations
Claude Code is now available in the desktop app, unlocking multiple parallel sessions where one agent might handle bugs, another researches repositories, and a third updates documentation. The Claude app has improved long-context handling through automatic summarization, Claude for Chrome is broadly available to Max users for cross-tab tasks, and Claude for Excel has expanded beta access to Max, Team, and Enterprise users, all leveraging Opus 4.5’s strengths in computer use and long-running tasks.
Availability, Pricing, and Usage Limits
Claude Opus 4.5 is accessible through Anthropic’s own interfaces and partner cloud platforms, making it straightforward for both individuals and enterprises to adopt. Pricing at 5 USD for input and 25 USD for output per million tokens is designed to open up high-end capabilities to more use cases, with updated usage limits that remove Opus-specific caps for eligible Claude and Claude Code users.
Preparing for Future Frontier Models
For Max and Team Premium users, overall limits have been increased so that Opus token availability is roughly comparable to previous Sonnet allocations, supporting daily, production-grade use. Anthropic notes that these limits are specific to Opus 4.5 and are expected to evolve as even more capable future models are released.
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