AI Coding Roundup — September 4, 2026: Claude Code Ships a Live Diff Panel

Yesterday's roundup covered Claude Code 2.1.259, GitHub Copilot's new PR-approval power, and OpenAI's Codex CLI 0.153.0. In the time since, all four tools kept moving — most notably Claude Code, which jumped to 2.1.260 with a genuinely new feature: a live diff panel. Here's what's actually new today, sourced directly from each project's official changelog, with links so you can verify the details yourself.

Claude Code 2.1.260: A Live Diff Panel, Plus Cache Diagnostics

Anthropic pushed Claude Code to 2.1.260 within a day of the previous release. The standout addition is a diff panel that opens beside the conversation in fullscreen mode, showing uncommitted changes as Claude edits — toggle it any time with /diff. Alongside it, /cost and the status line's prompt_cache field now surface a likely cause when a prompt-cache miss occurs, such as a changed system prompt, updated tool definitions, or an idle session past its cache TTL. The release also bundles a long list of reliability fixes.

• /diff opens a live diff panel beside the conversation in fullscreen mode
• Prompt-cache miss diagnostics added to /cost and the status line
• /reload-plugins now works in Desktop, Remote Control, and headless SDK sessions
• Text form of /advisor available in desktop, Remote Control, and headless sessions
• oidc.scope_on_refresh added for identity providers that only return an id_token when openid is explicitly requested
• Critical fixes: permission rules with parentheses no longer get dropped, a single invalid rule no longer breaks all file edits, and Bedrock credential calls no longer fail on machines using a corporate root CA

Full release notes: Claude Code changelog.

GitHub Copilot: Content Exclusions Reach General Availability

On September 2, GitHub graduated content exclusions from preview to general availability across both the Copilot app and Copilot CLI. Enterprise, organization, and repository admins can now configure policies that stop Copilot from pulling excluded files into context — including inside agentic workflows — closing a gap for teams that need to keep certain paths, like secrets or compliance-sensitive code, out of every Copilot interaction, not just chat.

• Generally available in the Copilot app and Copilot CLI
• Available to Copilot Business and Copilot Enterprise plans
• Exclusion policies now apply across agentic workflows, not just chat completions

Details: GitHub Changelog — Content exclusions generally available.

OpenAI Codex CLI: Two Quick Patches for GPT-6-Astra

OpenAI followed 0.153.0 with two small same-day patches. Version 0.153.1 adds support for configuring the GPT-6-Astra model through the API, and 0.153.2 fixes an incorrect description string for its Fast tier. Neither is a major feature, but the pace shows OpenAI is still actively tuning GPT-6-Astra's rollout inside Codex CLI.

Full changelog: OpenAI Codex changelog.

OpenCode: Nothing New Since 1.18.27

OpenCode's most recent release is still 1.18.27 from September 2, which tightened Claude 5.1+ thinking-block handling and defaulted provider timeouts to five minutes. No new version has shipped as of this check — likely a quiet stretch while those changes bake before the next release.

Full changelog: OpenCode changelog.

Why It Matters

The diff panel is the biggest deal here — reviewing Claude's edits without leaving the conversation removes real friction for anyone driving larger changes through Claude Code. Copilot's content-exclusion GA is the other one worth acting on: if your org handles regulated or proprietary code, audit your exclusion policies now that the feature is fully supported rather than preview-only. The Codex and OpenCode updates are maintenance rather than milestones, but worth knowing if you're pinned to a specific version.

Resources & References

• Claude Code Changelog
• GitHub Changelog: Content exclusions generally available
• OpenAI Codex / ChatGPT Changelog
• OpenCode Changelog