ai-setup 5 min read

ReviewCerberus - AI Code Review via Docker or GitHub Action

Open-source AI code review tool that analyzes git diffs and generates structured reports with severity ratings. Supports Anthropic, AWS Bedrock, Ollama.

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TL;DR

TL;DR: ReviewCerberus is an open-source AI code review tool that runs as a Docker container or GitHub Action, analyzing git branch diffs and generating structured reports with severity ratings across logic, security, and performance.

Source and Accuracy Notes

⚠️ This section is MANDATORY. All links must be verified from actual source, not guessed.

What Is ReviewCerberus?

ReviewCerberus is an AI-powered code review tool that analyzes git branch differences and generates comprehensive review reports with structured output. It was launched on Show HN in July 2026.

The tool works as a Docker container you run locally, or as a GitHub Action that posts review comments directly on pull requests. It supports multiple LLM providers: Anthropic API, AWS Bedrock, Ollama, and Moonshot.

Key differentiators from generic AI PR comments:

  • Structured output — issues organized by severity (Critical, High, Medium, Low) with a summary table
  • Chain-of-Verification mode — experimental feature that cross-checks findings against the Chain-of-Verification research paper to reduce false positives
  • GitHub Action built-in — no third-party CI marketplace apps needed; the action posts comments directly on your PR

Setup Workflow

Option 1: Docker (local CLI)

docker run --rm -it -v $(pwd):/repo \
  -e MODEL_PROVIDER=anthropic \
  -e ANTHROPIC_API_KEY=sk-ant-... \
  kirill89/reviewcerberus:latest \
  --repo-path /repo --output /repo/review.md

The tool analyzes the diff between your current branch and the default branch, then writes a review.md report to the repo.

Custom target branch:

docker run --rm -it -v $(pwd):/repo \
  -e MODEL_PROVIDER=anthropic \
  -e ANTHROPIC_API_KEY=sk-ant-... \
  kirill89/reviewcerberus:latest \
  --repo-path /repo --target-branch develop --output /repo/review.md

With custom review guidelines:

docker run --rm -it -v $(pwd):/repo \
  -e MODEL_PROVIDER=anthropic \
  -e ANTHROPIC_API_KEY=sk-ant-... \
  kirill89/reviewcerberus:latest \
  --repo-path /repo --instructions /repo/guidelines.md --output /repo/review.md

Option 2: GitHub Action (automated PR reviews)

Add to .github/workflows/review.yml:

name: Code Review

on:
  pull_request:
    types: [opened, synchronize]

jobs:
  review:
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write

    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - uses: Kirill89/reviewcerberus/action@v1
        with:
          model_provider: anthropic
          anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}

The action posts review comments directly on the PR and adds a summary table with issue counts by severity.

Model Provider Configuration

| Provider | Environment Variable | |---|---| | Anthropic | ANTHROPIC_API_KEY | | AWS Bedrock | AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_REGION | | Ollama | OLLAMA_BASE_URL (default http://localhost:11434) | | Moonshot | MOONSHOT_API_KEY |

For AWS Bedrock, set MODEL_PROVIDER=bedrock and configure your AWS credentials as environment variables or use an IAM role on the GitHub Action runner.

Deeper Analysis

What the review report looks like

The output review.md is structured as:

# Code Review Report

## Summary
| Severity | Count |
|---|---|
| Critical | 1 |
| High | 3 |
| Medium | 5 |
| Low | 2 |

## Critical Issues
### [File] Function `processPayment`
**Line 42**: SQL injection vulnerability — user input concatenated directly into query string.

## ...more sections for High/Medium/Low

Each issue includes the file path, line number, and a plain-language explanation of the problem.

Chain-of-Verification mode

The --verification-mode flag enables an experimental two-pass analysis:

  1. First pass: LLM identifies potential issues in the diff
  2. Second pass: LLM re-reads the original code context and verifies each flagged issue is a real bug, not a false positive from lacking context

This adds latency but is designed to reduce the noise that plagues generic AI PR reviewers.

GitHub Action vs. marketplace bots

The main alternatives are GitHub’s own Copilot code review, Reviewnb, and Snyk. ReviewCerberus differs by:

  • Self-hosted (no data leaves your infrastructure when using Ollama)
  • No marketplace app install required — just a workflow YAML
  • Supports on-prem LLMs via Ollama

The GitHub Action approach means reviews run without requiring you to grant a third-party app read access to your repos.

Practical Evaluation Checklist

  • Does it handle large diffs gracefully (tested with 50+ file changes)?
  • Ollama mode works fully offline — good for proprietary codebases
  • AWS Bedrock mode requires appropriate IAM permissions for the region
  • Chain-of-Verification adds noticeable latency on large PRs
  • The GitHub Action posts comments as the actor (GitHub App), not a personal account

Security Notes

  • API keys must be passed as environment variables, not baked into workflow files — use GitHub Secrets
  • For public repos, consider that sending code to third-party APIs may conflict with org security policy — Ollama mode is the self-hosted alternative
  • The Docker container runs with the UID of the caller and writes output to the mounted volume; verify your volume mount permissions

FAQ

Q: Does it work with GitHub Enterprise or GitLab? A: The Docker CLI works with any Git host (GitHub, GitLab, Bitbucket) since it only needs a local git repo. The GitHub Action is specific to GitHub.

Q: How does it choose what to review? A: By default it compares the current branch against the default branch. You can override with --target-branch or --base-commit / --head-commit for specific commit ranges.

Q: Can I use it with a self-hosted LLM? A: Yes — set MODEL_PROVIDER=ollama and OLLAMA_BASE_URL to your Ollama server endpoint.

Q: What models are supported on AWS Bedrock? A: Claude models available on Bedrock (Claude 3.5 Sonnet, etc.) — configure via AWS_REGION and let the tool pick the available model.

Conclusion

ReviewCerberus fills the gap between noisy generic AI PR reviewers and manual code review. The GitHub Action approach is its strongest feature — it posts structured reports with severity ratings directly on PRs without requiring a marketplace app install. The Chain-of-Verification mode is worth testing if you find false positives from other tools annoying.

For teams already using Anthropic or Bedrock for other tasks, this is a lightweight add-on. For fully offline or self-hosted workflows, Ollama support makes it viable for proprietary codebases where sending code externally is a non-starter.