Daily AI Builder Brief - April 28, 2026

Executive Summary

Claude Code v2.1.121 adds alwaysLoad to MCP server config so chosen tools skip ToolSearch deferral.
v2.1.121 lets PostToolUse hooks rewrite output for any tool via hookSpecificOutput.updatedToolOutput, not just MCP.
v2.1.120 drops the Git for Windows requirement and falls back to PowerShell as the shell tool.
v2.1.120 adds claude ultrareview [target] for non-interactive /ultrareview runs in CI with --json and exit codes.
Multi-GB memory leaks during image-heavy sessions, large /usage transcripts, and stalled long-running tools are patched.
AWS and Anthropic announced silicon-level co-engineering on Trainium and Graviton; Claude Cowork is live in Amazon Bedrock.
Anthropic opened its Sydney office on 2026-04-27 with Canva integrating into Claude Design and Xero embedding Claude.
No MCP spec drop or notable official-server release in the past 48 hours.

Claude Code

v2.1.121 ships `alwaysLoad` for MCP servers

Set alwaysLoad: true on a server and its tools bypass ToolSearch deferral, staying immediately callable. Right move for the one or two servers you need every turn. Source: Claude Code changelog

PostToolUse hooks rewrite any tool's output

Previously MCP-only; v2.1.121 extends updatedToolOutput across all tools. You can redact, summarize, or post-process Bash, Edit, Write, and Grep results before the model sees them. Source: Claude Code changelog

Memory leaks fixed in v2.1.121

Fixes for unbounded RSS on image-heavy sessions, ~2GB leaks from /usage with large transcripts, and leaks when long-running tools fail to emit progress. Bash no longer dies permanently when its starting cwd is deleted mid-session. Source: Claude Code changelog

v2.1.120 drops Git for Windows requirement

Windows users without Git Bash get PowerShell automatically. Same release adds claude ultrareview for CI: stdout findings, --json for raw output, exit 0 on completion or 1 on failure. Source: Claude Code changelog

Anthropic

Sydney office opens with Canva and Xero deals

Theo Hourmouzis (ex-Snowflake APJ SVP) leads Anthropic ANZ. Canva is integrating into Claude Design; Xero is embedding Claude. Tokyo and Bengaluru already open; Seoul next. Source: Anthropic news

MCP Ecosystem

No official drop in the last 48 hours

The most recent post on the MCP blog is the 2026-04-08 maintainer team expansion (Clare Liguori joins core; Den Delimarsky becomes lead alongside David Soria Parra). Spec activity since November 2025 has been SEPs (Tasks, Triggers, OAuth 2.1) on the roadmap, not a new version. Source: MCP blog

Broader AI

AWS and Anthropic deepen silicon co-engineering

Anthropic is training top models on AWS Trainium and Graviton, co-engineering with Annapurna Labs at the silicon level. Claude Cowork is live in Amazon Bedrock (data stays in your AWS account); Claude Platform on AWS is coming. Source: AWS Weekly Roundup, 2026-04-27

What This Means For Builders

Pin Bash-heavy or image-heavy agent sessions to v2.1.121; budget less RAM headroom in CI workers.
If you ship to Windows shops without Git Bash, stop bundling it. v2.1.120 falls back to PowerShell.
Move always-needed MCP servers to alwaysLoad: true; keep infrequent ones deferred. Cuts cold-turn latency.
If you already run on AWS, plan Claude Cowork in Bedrock as the lowest-friction path to keep data in-account.