Anthropic Unveils Claude Code Team's Internal Verification Loop with Four Automated Checks

Anthropic on July 22 disclosed the Claude Code team's internal verification loop. The loop enables Claude to automatically perform four checks after writing code: code-review to find and fix bugs, simplify to reduce redundant implementations, verify for end-to-end validation, and design to check visual alignment against the DESIGN. md file when changes are made. This changes the agent workflow from the original process of gathering context, executing actions, and manual review, to an iterative process of gathering context, executing actions, automated verification, repair, and re-verification.

The Claude Code team uses these four skills daily for self-checking. Code-review specifically examines code changes, identifies potential bugs, and provides review comments. Simplify cleans up the diff of the current changes, removing convoluted implementations to make the structure simpler. Verify performs end-to-end validation to confirm functionality is complete. Design is used when UI changes are made, checking visual implementation line by line against the DESIGN. md in the repository. These skills rely on the verification support built into Claude Code: the built-in /verify runs the application to observe changes; build and test commands specified in CLAUDE. md are executed; there is also a Code Review feature for multi-agent review on pull requests, and GitHub Actions that can automatically fire on every commit.

Anthropic provided a method for writing verification skills: write down each manual check in plain language, as if explaining to a new colleague. If the description is unclear, first ask Claude to generate a generic best practice and then revise. Example checks: any change that deletes a database field without a corresponding data migration step should be rejected. Written skills can be given to skill-creator or placed directly into Markdown files in the . claude/skills/ directory. For built-in skills that cannot be modified, one can write a wrapper skill that first calls the original and then runs its own verification.

Verification skills have four automation levels: Standalone for manual triggering, Embedded for embedding into task workflows, Chained for chaining multiple verification skills to execute automatically, and On every PR for automatic execution on every code commit. Skills are becoming a cross-vendor open standard; GitHub Copilot, Cursor, OpenAI Codex, and Gemini CLI have adopted the same format. This means that skills accumulated for a team are not locked into a single tool.