Rebuild Dossier MCP server

rebuild-dossier

An MCP server that reverse-engineers a trustworthy rebuild spec — a locked CLAUDE.md, .claude/ config, and a mutation-tested test suite — out of an existing app, so any coding agent can rebuild it cleanly against that spec instead of guessing.

It does not rebuild the app. It produces the spec, contracts, and tests a coding agent consumes to do that separately. This boundary is deliberate — see Why below.

Validated against a real app. The core loop (ingest, resolve cases, generate spec) has been

tested end-to-end against a real, messy repo with two independent fresh-agent handoffs on two

model tiers, plus a mutation-tested test suite.

docs/v0-findings.md covers what worked, what broke, and what's still open.

Quick start

Available on npm:

npx rebuild-dossier@latest --help    # pulls and verifies the package, or:
npm install -g rebuild-dossier        # install the CLI globally

Requires Node 20.12+ (set in package.json engines). To run from source instead, clone the repo, npm install, and use npm start.

Then add it as an MCP server. In Claude Code, from the project you want to rebuild:

claude mcp add rebuild-dossier -- npx -y rebuild-dossier@latest

(or add this to your ~/.claude.json / project .mcp.json):

{
  "mcpServers": {
    "rebuild-dossier": {
      "command": "npx",
      "args": ["-y", "rebuild-dossier@latest"]
    }
  }
}

Then in a session. The first call, ingest_repo, runs instantly with zero setup: static analysis only, no browser, no Chromium, no LLM call. Run it on any app to confirm the server is alive before committing to the full workflow:

ingest_repo({ path: "/path/to/some-app" })
get_case_queue({ repoPath: "/path/to/some-app", interactive: true })
# ...resolve whatever the queue surfaces...
generate_spec({ repoPath: "/path/to/some-app" })

This writes a clean some-app-rebuild/ sibling directory. cd into it, start a fresh Claude Code session (nothing else should be in scope), and paste the contents of its kickoff-prompt.txt.

If this looks useful, a star helps other developers find it.

Why

Prior research (AgentModernize, arXiv:2605.17535) found that a rebuild pipeline scores 0% behavioral equivalence with no verified feedback loop, and only 9–19% with a coarse one. The bet behind this tool: locking interface contracts before running tests, plus a strict one-test-at-a-time retry loop instead of batch regeneration, does meaningfully better.

The riskiest part of any such pipeline is silently validating a bug as intentional — four sources of evidence can quietly agree on the same mistake with nobody ever having said why. So the single non-negotiable rule in this tool: auto-resolving an ambiguity requires both signal agreement and an affirmative signal that someone actually decided (a stated comment, a TODO admitting a bug, or a direct human answer). Silent agreement alone — code and observed behavior simply matching, with no one ever having said why — always becomes a question, never an auto-resolution, no matter how high the apparent confidence.

How it works

Shortened. The full README is on GitHub.