Daily AI Builder Brief - May 16, 2026

Executive Summary

Claude Code 2.1.143 ships plugin dependency enforcement: disable refuses if dependents are enabled, enable force-enables transitive deps.
Projected context cost (per-turn and per-invocation token estimates) now shows in the /plugin marketplace browse pane.
New worktree.bgIsolation: "none" lets background sessions edit the working copy directly when worktrees aren't practical.
Fast mode now defaults to Opus 4.7 (set CLAUDE_CODE_OPUS_4_6_FAST_MODE_OVERRIDE=1 to pin 4.6).
Anthropic announced a split-billing model effective June 15: Pool 1 for interactive use, Pool 2 for Agent SDK programmatic calls.
Claude Platform on AWS hit GA with Opus 4.7, Sonnet 4.6, Haiku 4.5 via AWS auth and billing.
Advisor tool is in beta natively on the Claude Platform.
MCP 2026 roadmap formalizes Server Cards (.well-known discovery) and stateless transport for horizontal scaling.

Claude Code

2.1.143 plugin dependency graph and cost preview

Plugin dep enforcement, /plugin cost projection, worktree.bgIsolation: "none", PowerShell -ExecutionPolicy Bypass by default. Background sessions now persist model and effort after idle wake. changelog

2.1.142 background agent flags and fast mode bump

claude agents gains --add-dir, --settings, --mcp-config, --plugin-dir, --permission-mode, --model, --effort, --dangerously-skip-permissions. Root-level SKILL.md plugins surface as skills. MCP_TOOL_TIMEOUT now actually raises remote HTTP/SSE fetch timeout. changelog

Anthropic

Split-billing rollout for Agent SDK (effective June 15)

Two pools: interactive (humans driving Claude) vs Agent SDK (code driving Claude). Plan for separate budget tracking before mid-June or programmatic workloads will throttle differently than today. InfoWorld

Claude Platform GA on AWS

Full Platform feature set with AWS auth, billing, and commitment retirement. Opus 4.7, Sonnet 4.6, Haiku 4.5 available; new models ship on AWS at launch. Anthropic news

Advisor tool in beta

Native on the Claude Platform. Useful if you're building agent loops that want a model-side reviewer instead of a homegrown one. Anthropic news

MCP Ecosystem

2026 roadmap: Server Cards and stateless transport

Server Cards expose structured metadata at a .well-known URL so registries can discover capabilities without connecting. Transport work targets horizontal scaling without sticky session state. Enterprise track adds audit trails, SSO auth, gateway behavior, config portability. MCP roadmap

Broader AI

Nothing today.

What This Means For Builders

If you're shipping Agent SDK workloads, model the June 15 split now: separate API keys per pool make accounting and rate-limit triage clean.
Plugin authors should declare deps explicitly; the new disable-chain enforcement breaks loose plugin coupling silently if you don't.
Stop hand-rolling MCP server discovery; the Server Card spec is the path that will get registry and gateway support.
Fast-mode users on Opus 4.6 prompts should re-test on 4.7 or pin the override; behavior drift on terse system prompts is the usual surprise.