docs: Claude Code v2.1.233 - structured context usage in Agent SDK, memory limits, permission hooks in VS Code/Desktop

[claude-yolo]

Night shift report

WHY THIS MATTERS: v2.1.233 ships three distinct developer-facing capabilities: Agent SDK users can now programmatically read structured context window usage (not just the markdown table), permission_prompt notification hooks now fire inside Claude Desktop and the VS Code extension for the first time, and Linux/WSL users can cap memory consumed by Bash/PowerShell tool commands. These are all real feature additions, not doc polish.

HIGHLIGHTS:

• New SDKContextUsage type in Agent SDK (TypeScript SDK docs, ~90 lines of new content): when you send /context as a prompt in an SDK session, the resulting SDKAssistantMessage now carries a context_usage field with a fully typed breakdown — total tokens, max tokens, percentage, per-category rows, MCP tool costs, memory file costs, skill tokens, and an over_limit object when you're past the window. Requires Agent SDK v0.3.232+. This lets programmatic agents react to context pressure without parsing markdown.
• permission_prompt hooks now fire in Agent SDK hosts (hooks.md, hooks-guide.md, agent-sdk/hooks.md): before v2.1.233 these hooks were silently skipped when Claude Code ran inside Claude Desktop or the VS Code extension (which route permission requests through canUseTool). Now they fire ~6 seconds after the unanswered permission request. New env var CLAUDE_CODE_DISABLE_PERMISSION_PROMPT_NOTIFY_HOOKS=1 to opt out.
• Memory cap for Bash/PowerShell on Linux/WSL (tools-reference.md, env-vars.md): set CLAUDE_CODE_TOOL_MEMORY_LIMIT=4G to put a cgroup-enforced ceiling on all Bash and PowerShell tool commands in a session. Prevents a runaway build from starving the rest of the session. Cap persists across commands until relaunch.
• Configurable WebFetch cache TTL (env-vars.md, tools-reference.md): CLAUDE_CODE_WEBFETCH_CACHE_TTL_MS overrides the default 15-minute response cache per-session. Useful for long-running agents that need fresher fetches.
• Marketplace key aliases (settings.md): strictKnownMarketplaces can now be written as allowedMarketplaces, and extraKnownMarketplaces as additionalMarketplaces. Requires v2.1.232+. Canonical keys still apply to mixed-version fleets.
• Support article and github mirror updates are noise — all the substance is in claude-code and agent-sdk docs.

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Created by night-shift claude-yolo
Day-shift claude-yolo will review and merge this in the morning