AI Coding Tools Roundup: Claude Code 2.1.299, Gemini 4 in Copilot, Codex 0.162 and OpenCode 1.19

A packed week for AI coding tools. Claude Code climbed to v2.1.299 per its GitHub releases, GitHub Copilot added a new Gemini model and generally available sandboxing in its changelog, Codex 0.162 shipped managed worktrees, and OpenCode 1.19 paved the way to OpenCode 2.

Claude Code: v2.1.293 to v2.1.299

Seven point releases landed since our last roundup. The highlights:

• Idle compaction (2.1.299): conversations over 200K tokens that sit idle for about 54 minutes are compacted before the one-hour prompt cache expires. Tune with CLAUDE_CODE_IDLE_COMPACT_MIN_TOKENS or disable it with "idleCompaction": false.
• Claude Haiku 5.5 (2.1.293): claude-haiku-5-5 is now the default Haiku, with 1M context at $0.10/$0.50 per million tokens.
• Hook safety (2.1.295): new onFailure: "block" makes a command or HTTP hook that fails to start, times out or exits unexpectedly block the action instead of silently passing.
• Workflow and cost controls (2.1.296): CLAUDE_CODE_WORKFLOW_SUBAGENT_MODEL runs all workflow agents on one model, subagents gain autoCompactWindow, and Sonnet 5.5 cache reads drop to $0.10/M tokens (from $0.20).
• Fixes: WSL2 sandbox failures, scheduled wakeups not firing in Agent SDK and IDE sessions, and a memory leak in HTTP MCP connections.

GitHub Copilot: Gemini 4 Argon, GA Sandboxing and Haiku 5.5

Gemini 4 Argon is rolling out gradually to Pro+, Max, Business and Enterprise, available in the model pickers of VS Code, Visual Studio, Copilot CLI, the coding agent, JetBrains, Xcode and Eclipse. It is billed at provider list pricing under usage-based billing; admins can control it through the model policy. Also this week: local sandboxing is generally available, Claude Haiku 5.5 joined Copilot, Copilot CLI can discover local models, and code review gained new organization billing controls.

OpenAI Codex 0.162

Per the Codex release notes, 0.162.0 (Oct 8) adds managed Git worktree tools, task pinning in the Command Center, clickable URLs in TUI prompts and custom provider capability settings, plus fixes for Linux sandbox startup and Windows drive-letter access. Stable 0.162.1 (Oct 9) fixes a TUI crash and background-server startup mismatches. 0.163 alphas ship daily.

OpenCode 1.19: The Road to v2

OpenCode v1.19.0 (Oct 11) introduces opencode upgrade --major to move to OpenCode 2. Updates are now manual via /update in the TUI, and a security fix validates PTY connection origin and ticket first.

What to do today

• Update Claude Code to 2.1.299 and review idle compaction if you keep long sessions open.
• Add onFailure: "block" to security-critical hooks.
• Try Copilot's sandboxing before running agents on untrusted repos.
• OpenCode users: updates no longer install automatically, so run /update.

Sources

• Claude Code releases · GitHub Copilot changelog · Codex releases · OpenCode releases