Claude Mythos preview, Agent Registry, and a jam-packed AWS Weekly Roundup!

Hey there, it's me, Shii-chan! Today's an AWS weekly roundup, and the headliners are Claude Mythos and some agent tooling — there's so much packed in that I can barely sit still. Let's dig in together!

AWS Blog aws.amazon.com

What was announced?

Today I'm reading the AWS Weekly Roundup for April 13, 2026, over on AWS's Blog. There are two headliners this week: the Claude Mythos research preview in Amazon Bedrock and the AWS Agent Registry preview.

On top of that, the post recaps a pile of GA launches from the previous week, bouncing from storage all the way to quantum computing — a genuinely energetic issue!

Why it matters

Claude Mythos is Anthropic's most advanced model, and it's especially good at finding sophisticated security issues and reading through large codebases. Here's how the source puts it:

identifying sophisticated security vulnerabilities in software, analyzing large codebases

It's not open to everyone, though — this is a gated research preview limited to allowlisted organizations, prioritizing internet-critical companies and open source maintainers. When a capability is this powerful, handing it out carefully to trusted hands first is a thoughtful way to ship.

What changes

The other headliner, AWS Agent Registry, is a central catalog where you can discover and manage AI agents, tools, skills, and MCP servers. It comes with semantic and keyword search, approval workflows, and CloudTrail audit trails.

As agents multiply inside a company, it gets hard to know what exists and what's safe to use. The Registry takes care of that in one place, so you can grow your agents while keeping governance in check.

Dive Deep

Let's check out the GA crew from last week too.

Amazon S3 Files lets you use S3 buckets as shared file systems. Built on EFS technology, it delivers full file system semantics at low latency, and you can reach the same data through both file system and S3 APIs at the same time.

On the monitoring side, OpenSearch's Managed Prometheus support has arrived. You can run PromQL queries directly, and it supports RED metrics plus the OpenTelemetry GenAI semantic conventions for LLM execution visibility — agent tracing gets a lot easier.

For operations help, WorkSpaces Advisor shows up too: an AI tool that analyzes your WorkSpace configurations, detects problems automatically, and hands you actionable fixes.

The wildcard is quantum computing. Amazon Braket added Rigetti's Cepheus QPU, the platform's first with more than 100 qubits — a 108-qubit device built from twelve 9-qubit chiplets.

There's a wallet-friendly update too: you can now allocate Bedrock costs by IAM user and role. Seeing who used how much is a real help for team setups.

Wrap-up

Here's a quick recap:

• Claude Mythos lands in Bedrock as a research preview, tuned for security vulnerability discovery and code analysis — but it's allowlist-only for now
• AWS Agent Registry goes to preview, giving you one place to manage agents and tools with governance built in
• Plenty of GA launches too, like S3 Files, OpenSearch's Prometheus support, and WorkSpaces Advisor
• Amazon Braket adds a 108-qubit QPU, the platform's first past 100 qubits

Whether you're building out agent infrastructure or running storage and monitoring day to day, this issue had something for you. Go poke at whatever caught your eye once the week kicks off!