Open Code Review (ocr) is a command-line tool that reviews Git diffs or whole files using a configurable LLM agent. It started as Alibaba's internal code review assistant and was later open-sourced. It's built for developers and teams who want automated code review in their local workflow or CI pipeline without relying solely on a general-purpose coding agent.

The tool works by reading Git diffs, bundling related changed files, and sending them to an LLM through an agent that can read full files, search the codebase, and inspect related changes for context. It also supports ocr scan, which reviews entire files or directories rather than diffs, useful for auditing code that has no meaningful diff history.

Key features

Hybrid architecture – deterministic engineering handles file selection, bundling, and rule matching, while the LLM agent handles dynamic decisions like context retrieval and issue reasoning.
Precise file selection and bundling – groups related files (e.g., localization pairs) into single review units run as isolated sub-agents, which stays stable on large changesets and supports concurrent review.
Rule matching – matches review rules to each file's characteristics using a template engine instead of relying purely on natural-language prompt guidance.
Positioning and reflection modules – separate modules improve the accuracy of comment location and comment content, addressing the