Developer tools often lack proper audit trails for AI-assisted coding. Ponytrail addresses this gap with a lightweight CLI that captures every file modification made by AI agents, storing the complete history in a .pony-trail/ directory within your project. The tool records not just what changed, but why it changed, creating a searchable timeline of agent-driven edits.

Installation integrates directly with major AI coding assistants. Running npx ponytrail skills install pony-trail bundles the tool into Claude, Copilot, and Codex environments, automatically capturing snapshots before and after skill modifications. The history command displays a tree structure showing actions, summaries, and rollback details, while --session and --json flags enable targeted queries and programmatic access to the audit data.

Reverting follows a deliberate approval workflow. The revert command previews planned file actions before execution, requiring explicit confirmation in interactive mode. Non-interactive environments receive the plan but halt without making changes, preventing accidental mutations. During rollback, Ponytrail restores files to their pre-snapshot state and removes any files that didn't exist before the recorded change.

Built with Bun for fast performance, Ponytrail fills a critical need in AI-assisted development workflows. As coding agents become standard practice, having reliable local history becomes essential for debugging unexpected changes and maintaining code quality. The tool's focused scope and thoughtful design suggest it could become a standard part of the AI coding toolkit.