opendrs MCP server

opendrs: PR blast radius analyzer and risk score for safe auto-approval

A calibrated 0-1 risk score for every pull request, so AI-reviewed, low-blast-radius PRs can be auto-approved into the merge queue while risky ones still wait for a human.

AI agents now write and review code faster than people can read it, so human review has become the bottleneck. Most pull requests are low risk, and a few cause most incidents. opendrs measures each PR's blast radius and risk: what the change touches, how many files depend on it, the history of the files it changes, author experience, missing tests and critical paths. It turns that into a 0-1 score using signals from your own git history. A team then sets a policy. For example, a PR that scores below 0.3 and has passed an AI review (Claude, CodeRabbit, Copilot or any check run) is approved and sent to the merge queue or auto-merge. Riskier PRs still wait for a human. The approach follows Meta's Diff Risk Score (DRS); opendrs is an independent, open-source implementation that runs in any git repository, with no service to host.

Use it as:

• a GitHub Action: error-path/opendrs@v0, which comments, labels and, optionally, approves and merges;
• a CLI: npx @error-path/opendrs score;
• a Claude Code plugin (skill plus MCP server): /plugin marketplace add error-path/opendrs, then /plugin install opendrs@opendrs;
• an agent skill for Claude Code, Cursor, Codex and others: npx skills add error-path/opendrs;
• an MCP server for any agent: npx -y @error-path/opendrs mcp.

Website and guides: error-path.github.io/opendrs, including how to auto-approve low-risk PRs and how opendrs compares with other PR risk tools.

Contents: Quick start · How it works · Signals · Policy and safety rails · Calibrate and backtest · Results · LLM judge · MCP and skill · CLI · Configuration · Limitations · Compared with other tools

Quick start

Score your current branch against the default branch. No configuration or API key is needed:

npx @error-path/opendrs score

You get a score, a tier (green, yellow or red), the signals that drove it with their evidence, and the policy decision. --json prints the full result, and --fail-above 0.6 makes the command exit 1 above a threshold.

To score every pull request, add .github/workflows/opendrs.yml (or run npx @error-path/opendrs init):

name: opendrs
on:
  pull_request:
    types: [opened, synchronize, reopened, ready_for_review]
permissions:
  contents: read
  pull-requests: write
  checks: read
jobs:
  opendrs:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v5
        with:
          fetch-depth: 0   # required: the score reads past commits and authors
      - uses: error-path/opendrs@v0

This only comments and labels. Approval is off until you turn it on in .opendrs.yml on your default branch; see docs/github-action.md.

How it works

Shortened. The full README is on GitHub.