For open source maintainers and coding agents

Reproduce the bug in the environment where it was reported.

twin records the environment a command failed in, rebuilds it on a clean Solari sandbox, finds the difference that causes the failure, and checks a fix there. 

$ npm install -g @crypticsaiyan/twincli

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How it works

Four commands, one file between them

  1. twin capture -- <command>

    Run the command and record the environment it failed in.

  2. twin replay <capsule>

    Rebuild it on a clean Solari sandbox and rerun the command.

  3. twin bisect <bad> --good <good>

    Find the smallest difference that makes it fail.

  4. twin verify <capsule> --patch <file>

    Check a fix in the reporter’s environment.

Full reference

For agents

Give coding agents the reporter’s machine

twin’s MCP server lets an agent replay the failure, run commands in the reporter’s environment, and verify its diff on a fresh machine.

Agent guide

Add to Claude Code
$ claude mcp add twin -e SOLARI_API_KEY=slr_live_... -- npx -y @crypticsaiyan/twincli mcp

The GitHub Action verifies each pull request in the reporter’s environment and fails unless the bug is fixed.

Action reference

.github/workflows/twin.yml
on: pull_request
jobs:
  verify:
    runs-on: ubuntu-latest
    steps:
      - uses: crypticsaiyan/twin@main
        with:
          solari-api-key: ${{ secrets.SOLARI_API_KEY }}