RepoRescue — Verified Code Rescue

Paste broken Python code or a public GitHub repository. RepoRescue explains it, generates a minimal repair, runs before-and-after verification, and reports exactly what the evidence proves.

RepoRescue is not another “maybe try this” coding chatbot. Its differentiator is a verification protocol:

understand intent → reproduce failure → generate minimal fix → run the same case again → grade the evidence

The product serves beginners through one low-friction entry point while keeping repository reproduction as the advanced mode:

Why it is different

• Generated repair, not a checklist: the agent produces the candidate code.

• Before/after proof: a fix is “verified” only when the original fails and the repaired version passes the same stated case.

• Beginner-first result: users see the cause, change, and outcome before technical logs.

• Scoped claims: snippet execution, repository tests, official demos, and paper metrics are different evidence levels.

• Portable core: the same MCP tools can power XFYun Agent, OpenClaw, Codex, or another agent shell.

Related MCP server: RepoCrunch

Live competition architecture

User code / error / GitHub URL
              │
              ▼
     Generative agent decision
       ├─ explain and repair
       └─ select verification path
              │
              ▼
        RepoRescue MCP tools
       ├─ rescue_python_snippet
       ├─ inspect_github_project
       ├─ reproduce_python_project
       └─ windows_environment_probe
              │
              ▼
  readable result + diff + scoped evidence

Quick start: hosted Node MCP

The hosted launcher uses CPython WebAssembly for isolated snippet execution and for the allow-listed competition repository when native Python is unavailable.

npm install
npm test
node .\stdio-server.mjs

rescue_python_snippet

Supply original code and the AI-generated candidate. Optional cases provide stdin and expected stdout.

{
  "original_code": "numbers = [1, 2, 3]\nprint(numbers[3])",
  "candidate_code": "numbers = [1, 2, 3]\nprint(numbers[-1])",
  "test_cases": [
    {"name": "last item", "stdin": "", "expected_stdout": "3"}
  ]
}

The response records the original IndexError, the repaired output, case-level status, and a scoped S2/L1_SNIPPET_EXECUTION result. It never claims a whole project or paper was reproduced from this snippet run.

Local Python MCP

The Python server provides repository inspection and container-backed reproduction:

py -3.11 -m venv .venv
.venv\Scripts\python -m pip install -e ".[dev]"
.venv\Scripts\pytest
docker build -f sandbox/Dockerfile.python311 -t repo-rescue-python:3.11 .

$env:REPO_RESCUE_ALLOWED_REPOS="pallets/click"
.venv\Scripts\repo-rescue-mcp

The Streamable HTTP endpoint defaults to http://localhost:8000/mcp. Set REPO_RESCUE_TRANSPORT=stdio for a command-based host.

Repository tools

inspect_github_project

Read-only inspection of an allow-listed public repository. Returns the exact commit, bounded file tree, Python manifests, dependency declarations, version hints, risks, entry points, and suggested verification commands.

reproduce_python_project

Runs a fixed verification scope for an explicitly allow-listed Python repository and returns the actual command, exit code, duration, test counts, bounded logs, backend, and attestation. The result states whether it was a smoke test, selected suite, or broader run.

windows_environment_probe

Returns a copy-paste PowerShell probe. It never claims to read a user's computer automatically and does not change the machine.

Evidence levels

• S1: snippet executed.

• S2: original snippet failed and repaired snippet passed the same case.

• P1: repository and commit inspected; no execution claim.

• P2: dependencies resolved.

• P3: named repository test scope executed with recorded exit code.

• P4: documented official demo reproduced.

• P5: paper metric reproduced under a stated dataset, configuration, seed, and hardware boundary.

Current hosted competition evidence reaches S2 for safe Python snippets and P3 for the named core smoke scope on the allow-listed demo. It does not claim P4 or P5.

Verified Code Rescue Skill

skills/verified-code-rescue/SKILL.md packages the distinctive orchestration protocol for agent hosts. It routes snippets, files, and repositories; requires before/after evidence; grades the claim scope; and produces a beginner-readable answer before technical details.

This Skill is intentionally not a generic coding prompt. Its reusable value is the truth-preserving rescue workflow.

Safety boundary

• Snippet rescue limits source size and case count, permits only a small safe standard-library import set, rejects filesystem/process/network capabilities, and applies a deterministic execution budget.

• Repository execution remains allow-listed and constrained.

• The service does not read a user's computer, accept arbitrary shell commands, or execute private repositories.

• Public production should move untrusted repositories to gVisor or Firecracker, authenticate and rate-limit callers, scan archives, restrict outbound installation traffic, and expire stored source and logs.

Portfolio summary

Built a portable MCP-backed code rescue agent that combines generative debugging with constrained before/after execution, evidence-level grading, commit-pinned repository inspection, and verifiable test reports. Integrated the same tool layer with XFYun Agent and an agent-host Skill while preventing unexecuted AI suggestions from being presented as verified fixes.

Roadmap

• File and notebook upload with focused test generation.

• Dependency-conflict rescue with lockfile output.

• Patch application and rerun loop for repositories.

• Official-demo (P4) case and downloadable reproduction report.

• Optional GitHub Issue/PR output after explicit user confirmation.