Usage budget consumed in ~15 minutes starting April 20, no workload change

Problem

Starting April 20, 2026, my Claude Code usage budget is being consumed abnormally fast. In ~15 minutes of normal coding work I hit 15-30% of the 5-hour session budget. The same workload and project setup worked fine through April 19.

Most dramatic case earlier today: Session went from 0% → 45% within 2 minutes of starting a fresh conversation in the Claude Code desktop app.

Environment

• Plan: Claude Max 5x
• Claude Code version: 2.1.34
• OS: Windows 11 Home (10.0.26200)
• Surfaces affected: Both VS Code extension AND Claude Code desktop app
• Model: Claude Opus 4.7

What I tried (significant token reduction achieved, but still elevated vs pre-Apr 20)

1. Set 48 skills to name-only in ~/.claude/settings.json via skillOverrides → saved ~18K tokens/conversation
2. Deleted 10 agents that had been added (ads-related, ~17K tokens total) from ~/.claude/agents/
3. Removed unused MCP servers: stitch-mcp (failed), supabase (npm duplicate), obsidian → saved ~8K tokens/conversation
4. Deleted ~24 skills added on Apr 19 that were not needed

Total removed: ~43K tokens per conversation.

After all these reductions, usage is better (~1% per minute with Opus on active React work) but still noticeably higher than my baseline before April 20, on the same projects and workflows.

Suspected causes (not confirmed)

• A change in how the system prompt is assembled on April 20 release?
• Plugin-level SessionStart hook injections counted differently?
• Some internal change to token counting or budget accrual?

Happy to share full settings.json / MCP config / skill list privately if helpful for diagnostics.

Reproduction

1. Open Claude Code desktop app on Windows
2. Start new conversation (any project)
3. Ask for a small coding task
4. Watch session % climb 15-30% in the first minute or two

This does not happen on Sonnet at anywhere near the same rate.