Themis

Generic linters catch style. They do not catch the architectural decisions your team has learned the hard way. Themis is a self-hosted GitHub App that reviews pull requests by running an autonomous multi-step workflow: a GitHub App webhook delivers PR and comment events, the agent reads the diff, applies your repository’s review doctrine, and posts inline findings plus a structured summary covering verdict, a scoring table, and severity-ordered sections. It also answers reviewer questions inside PR conversation threads, closing the loop without requiring a human to re-read the diff from scratch.

The sharpest edge here is doctrine portability. Review rules live in a `.themis/` directory at the root of your repository — versioned, diffable, and scoped per repo. Different teams on different repos can run different standards through the same deployed instance. This sidesteps the common failure mode where a shared review tool applies one organization-wide config that satisfies nobody.

Themis fits teams that already hold Codex or Claude Max subscriptions and want to route PR review through those credentials rather than pay a separate SaaS vendor. It is MIT-licensed and ships a Dockerfile plus docker-compose, so the deployment path is defined. The wall appears when you need managed uptime: webhook delivery, container health, and model API availability all fall on whoever owns the deployment. Teams without internal infrastructure ownership will spend more time maintaining the bot than writing the doctrine it enforces.

The tool exposes no API of its own and has no hosted tier. Integration is entirely through the GitHub App webhook mechanism. The `.themis/` configuration directory is the primary interface for customization — the docs describe this as the source of review doctrine, though the depth and syntax of that configuration layer is not fully detailed in the public README.