Anthropic confirmed the existence of Claude Mythos 5 after an accidental leak of internal documents at the end of April. The model breaks all previous records: 10 trillion total parameters, with between 800 billion and 1.2 trillion active per inference thanks to a Mixture of Experts (MoE) architecture. It is, to date, the first language model with that scale of parameters confirmed by its creator. For developers and researchers in LATAM, understanding what Mythos 5 is and what differentiates it from previous versions is crucial for anticipating how software development will change in the coming months.

In this article we analyze the model's architecture, its differentiated capabilities, the restricted-access Project Glasswing program, and the concrete impact it could have on the work of developers, security teams, and technology companies in the region.

What is Claude Mythos 5?

Claude Mythos 5 is Anthropic's most advanced model to date. Its code name —Mythos— refers to its position as a model of unprecedented scale in the industry. With 10 trillion total parameters, it far surpasses any previously published model in terms of declared size.

The key to its design is the Mixture of Experts (MoE) architecture: instead of activating all the parameters in each query, Mythos 5 activates between 800 billion and 1.2 trillion parameters per inference. This allows high computational efficiency without sacrificing reasoning depth. It's the same principle used by models like DeepSeek V4, but taken to a much larger scale.

Notable capabilities

The leaked documents —later confirmed by Anthropic— describe Mythos 5 as exceptionally capable in two key areas:

• Advanced cybersecurity: The model can analyze code, detect attack vectors, propose mitigations, and generate technical security reports with a level of detail that surpasses previous models in the same family. This positions it as a first-tier tool for red team teams, pentesters, and security developers.

• Complex reasoning: In internal benchmarks, Mythos 5 surpasses Claude 3.7 Opus in mathematical reasoning tasks, multi-step planning, and solving problems with complex constraints. According to sources cited by TechCrunch, the model was tested in autonomous agent environments with results notably superior to any previous version.

If you're interested in understanding how large-scale models are transforming cybersecurity, you can also read the analysis of OpenAI's GPT-5.4-Cyber, the model specialized in vulnerability detection.

Project Glasswing: restricted access

For now, Claude Mythos 5 is not publicly available. Anthropic launched an early-access program called Project Glasswing, aimed at research organizations, security companies, and selected strategic partners.

The restricted access responds to a deliberate policy from Anthropic: to evaluate the model's impact in controlled environments before general availability. According to information published by AI Analytics Diaries on Medium, the program includes exhaustive security reviews and "catastrophic risk" evaluations following the company's Responsible Scaling Policy (RSP).

The question many developers are asking is when massive access will arrive. Anthropic did not confirm dates, but the sector's dynamics suggest that the general launch could occur in the coming months.

What it implies for the future of software

Mythos 5 is not just a leap in scale: it's a sign of where software development is heading. With a model capable of reasoning in multiple steps, executing autonomous agents, and analyzing code with expert depth, the developer's role starts to look more like that of a technical director who designs systems and verifies results, than that of someone who writes each line.

This has concrete implications for teams in LATAM:

• AI-assisted development workflows will become more sophisticated: it's no longer enough to use a copilot for autocompletion.

• Information security companies will have to integrate models like Mythos 5 into their analysis pipelines so as not to fall behind malicious actors who will also have access.

• The barrier to entry for building capable autonomous agents will drop significantly, democratizing capabilities that today require costly infrastructure.

For teams in the region, accessibility will depend on the price per token that Anthropic sets and on whether the Claude Pro and Team plans incorporate the model. So far, there is no official confirmation of costs or of a regional availability date.

Learn to work with the most advanced AI models

If you want to be prepared to integrate models like Claude Mythos 5 into real projects, these Coderhouse courses give you the necessary technical foundations:

• Introduction to Artificial Intelligence: ideal if you're starting out and want to understand how LLMs and the architecture of current models work, including MoE.

• AI Engineering: for developers who want to integrate language models into real applications, with a focus on APIs, advanced prompting, and production pipelines.

• AI Agents: if your goal is to build autonomous systems that take advantage of the multi-step reasoning capabilities that define Mythos 5.

Frequently asked questions

How many parameters does Claude Mythos 5 have?

Claude Mythos 5 has 10 trillion total parameters. Thanks to its Mixture of Experts (MoE) architecture, it activates between 800 billion and 1.2 trillion parameters for each inference, which makes it computationally efficient despite its enormous total scale.

Is it available to the general public?

Not yet. Currently, access to Claude Mythos 5 is limited to the Project Glasswing program, an early-access program for research organizations and strategic partners of Anthropic. There is no official public launch date.

How does Claude Mythos 5 differ from Claude 3.7 Opus?

The most important difference is the scale and the architecture. While Claude 3.7 Opus is a dense model, Mythos 5 uses MoE with a drastically larger total-parameter scale. In addition, it shows superior capabilities in cybersecurity and complex reasoning according to the internal benchmarks confirmed by Anthropic.

What is Anthropic's Responsible Scaling Policy?

The RSP (Responsible Scaling Policy) is Anthropic's internal framework for evaluating and managing the risks of its most advanced models. It includes capability thresholds above which additional security measures are required before publishing a model. Mythos 5 is being evaluated under this framework during the Glasswing program.

Why is it called Mythos 5?

The name Mythos is an internal code name that leaked along with the technical documentation. Anthropic has not confirmed whether that will be the model's definitive name at its public launch. The "5" refers to it being the fifth main generation of the Claude family.