Mighty Mouse

TL;DR: Mighty Mouse is a test-time compute scaling engine and MCP reliability server designed to make small local LLMs (gemma4:e4b) code with frontier-model precision and zero scope drift.

⚡ Headline Results & Impact

Evidence Note: Benchmark claims are backed by frozen Signal aggregate records in logs/metric_telemetry.json. The prospective real-project study is complete at 10 paired tasks. Mighty Mouse used 4 retry rounds vs 6 for the control and received 4.60 vs 4.30 mean blind-review quality. No generalized improvement was demonstrated on timing. See the real-project study report.

🎯 The Problem

Small, local open models (like gemma4:e4b) offer total privacy, zero API costs, and low latency, but raw execution fails ~72% of the time on non-trivial coding tasks. Without rigid guardrails, small models suffer from:

• Scope Drift & Rogue File Deletes: Editing or deleting unrelated workspace files.
• Hallucinated Retries: Repeating the exact same failing code in loop cycles.
• Context Overload: Attempting multi-file refactors without an upfront architectural blueprint.

⚙️ How It Works (4 Core Scaling Mechanisms)

Mighty Mouse acts as a high-reliability cognitive exoskeleton built around 4 test-time compute scaling mechanisms:

1. Two-Stage Blueprinting (<plan> $\rightarrow$ <act>):
   Isolates architectural planning (<plan>) from surgical execution (<act>) to eliminate scope drift before any file is touched.
2. Multi-Turn Traceback Feedback Loops:
   Extracts Pytest error stack traces, lints, and scope check failures, feeding them back into Turn 2 for immediate self-correction.
3. Dynamic Temperature Annealing ($T=0.0 \rightarrow 0.35 \rightarrow 0.70$):
   Automatically scales sampling temperature on retries to break out of deterministic error loops.
4. Best-of-$N$ Consensus Ranker:
   Evaluates candidate runs and locks in the draft with zero scope violations and the smallest clean diff.

🚀 Future Evolution & Roadmap

• Multi-Agent Swarm Orchestration: Splitting execution into specialized Planner, Coder, and Reviewer subagents.
• Real-Time IDE & MCP Hooks: Background self-healing directly inside Antigravity, Cursor, Claude Code, and Windsurf.
• Cross-Model Frontier Parity: Expanding perpetual benchmark evaluation to Llama 3 and Qwen models.

🔌 Supported Interfaces & Integrations

Mighty Mouse can be used as a Python Library, exposed as an MCP Server, or integrated into IDE workflows:

• Integrations: Antigravity, Claude Code, Codex, Cursor, Hermes, OpenClaw, and Windsurf.
• MCP Tools: protocol, verify, setup_workspace, verify_and_record.

Install

git clone https://github.com/JOHNNYMACONNY/mighty-mouse.git
cd mighty-mouse
python -m venv .venv
.venv/bin/pip install -e '.[dev]'

The core library and MCP transport support CPython 3.10, 3.11, 3.12, and 3.13.

Two-Stage Execution & Agent CLI

Run the agent in unified mode (default), planner mode, or coder mode:

# Stage 1: Generate architectural plan blueprint
python3 src/mighty_mouse/orchestrator/mighty_mouse_agent.py \
  configs/mighty_mouse_v1.yaml \
  tasks/benchmark/task_1001.json \
  --stage planner \
  --plan-file logs/blueprint.md

# Stage 2: Execute surgical code edits using generated blueprint
python3 src/mighty_mouse/orchestrator/mighty_mouse_agent.py \
  configs/mighty_mouse_v1.yaml \
  tasks/benchmark/task_1001.json \
  --stage coder \
  --plan-file logs/blueprint.md

Verify any project

From the command line, verify a workspace with auto-detected project checks:

mighty-mouse verify /path/to/project

For automation, add --json. Standard output contains exactly one JSON document for pass (0), check failure (1), and unusable workspace (2) outcomes:

mighty-mouse verify /path/to/project --json

The version 1 verify shape is:

{
  "schema_version": 1,
  "interface": "verify",
  "passed": true,
  "checks": [{"name": "tests", "passed": true, "output": "", "duration_sec": 0.25}],
  "summary": "Passed 1/1 verification checks.",
  "suggestions": [],
  "detected_projects": ["python", "node"],
  "warnings": []
}

Commands, changed-file scope, and the per-command timeout can be specified explicitly:

mighty-mouse verify . \
  --test-command "pytest -q" \
  --lint-command "ruff check ." \
  --build-command "python -m build" \
  --allowed-path src/ \
  --allowed-path tests/ \
  --timeout-sec 120

The command exits 0 when all applicable checks pass, 1 when verification runs and a check fails, and 2 for invalid input or an unusable workspace.

from mighty_mouse.verifier import verify

result = verify(
    workspace="/path/to/project",
    allowed_paths=["src/feature.py", "tests/"],
)

print(result.passed)
print(result.summary)
for check in result.checks:
    print(check.name, check.passed, check.duration_sec)

Without explicit commands, Mighty Mouse detects every applicable root ecosystem rather than choosing one. Python-only projects run pytest when tests are present and otherwise run a syntax check with a structured partial-coverage warning. Node-only projects select a usable test, lint, or build script. Mixed Python/Node projects run one applicable check family for each ecosystem, and a failure in either family fails the combined result.

Malformed Node metadata, missing Node scripts, and missing executables produce explicit non-passing checks plus actionable entries in warnings; they never result in a successful empty verification. detected_projects records the ecosystems considered by auto-detection. Explicit command overrides bypass auto-detection, so their results leave detected_projects empty rather than claiming detection ran. Human output labels detection warnings, while --json emits them only as JSON fields.

Rust and Go root markers continue to select their native test commands. You can override detection:

result = verify(
    workspace="/path/to/project",
    test_command="pytest -q",
    lint_command="ruff check .",
    build_command="python -m build",
    timeout_sec=120,
)

Commands are executed without a shell, but they still run with the verifier process's local permissions. Use explicit commands only in trusted workspaces.

Select a protocol

Show the medium-complexity protocol for a task (the default):

mighty-mouse protocol "Add JSON output to the CLI"
mighty-mouse protocol "Fix a typo" --complexity low
mighty-mouse protocol "Change authentication" --complexity high --json

Human output includes the selected protocol and its verification reminder. With --json, the version 1 protocol shape is:

{
  "schema_version": 1,
  "interface": "protocol",
  "task_description": "Fix a typo",
  "complexity": "low",
  "protocol_prompt": "# Mighty Mouse v9.1 — Low Complexity\n...",
  "verification_reminder": "After editing, run Mighty Mouse verification, fix failures, and retry for no more than three rounds."
}

MCP server

Install the separate transport package into the same environment:

.venv/bin/pip install -e ./mcp
.venv/bin/python -m mighty_mouse_mcp.server

The mighty-mouse server exposes:

• protocol(task_description, complexity): returns the pinned v9.1 low, medium, or high protocol.
• verify(workspace, ...): returns structured tests, lint, build, and scope results.
• setup_workspace(workspace, repository, ...): creates a pinned local MCP identity from either an Ollama manifest or an exact host-supplied model digest; no hand-written JSON is needed.
• verify_and_record(workspace, ...): verifies a task and writes a content-free v2 Signal receipt for learning aggregates using the pinned .mighty-mouse/mcp-adapter.json identity. It records no prompt, source, path, command, or verifier output.
• recording_audit(workspace, receipt_hash, after): supports optional host hooks that fail closed unless that task's returned receipt was recorded.

Generic stdio configuration:

{
  "mcpServers": {
    "mighty-mouse": {
      "command": "/absolute/path/to/.venv/bin/python",
      "args": ["-m", "mighty_mouse_mcp.server"]
    }
  }
}

Platform-specific rule files and MCP configuration shapes are documented in skills/README.md and skills/mcp-configs/.

Original benchmark CLI

mighty-mouse doctor
mighty-mouse doctor --live
mighty-mouse demo
mighty-mouse demo --live --model gemma4:e4b
mighty-mouse benchmark
mighty-mouse benchmark --tasks-dir ./my-tasks

The simulated demo replays recorded fixtures and does not execute a model. Live commands isolate logs and temporary workspaces under a reported output directory.

Reproduce the bare control

With Ollama running and gemma4:e4b installed:

PYTHONPATH=src python eval/run_bare_baseline.py --force

The runner requires exactly 15 frozen tasks, makes one generation request per task, retains every raw response, records model provenance and hashes, and never applies a Mighty Mouse protocol or retry loop.

Architecture

• src/mighty_mouse/verifier/: generic project verification public API.
• src/mighty_mouse/protocols/: versioned complexity-scaled protocols.
• mcp/: separately installable MCP transport.
• skills/: platform rules (antigravity, claude-code, codex, cursor, windsurf) and MCP configurations (hermes.yaml, openclaw.yaml, codex.json).
• src/mighty_mouse/orchestrator/: original local-model agent loop and scaling engine.
• src/mighty_mouse/services/: synthetic benchmark and legacy verification services.
• data/evidence/: frozen historical, bare-control, and real-project study artifacts.
• eval/: evidence runners, scaling suite, and automated tests.

Development

PYTHONPATH=src .venv/bin/python -m pytest -q
PYTHONPATH=eval:src:mcp/src .venv/bin/python scripts/check_changed_flake8.py --base HEAD^
.venv/bin/python -m build

The MCP package is built separately from mcp/. Release verification installs both wheels into a clean environment and exercises an actual stdio MCP session.

Default Flake8 reports a pre-existing repository baseline. Changed-line lint checks run through scripts/check_changed_flake8.py and fail only for new violations introduced by a Git diff. See docs/agents/quality.md.

GitHub Actions runs the complete test suite on every supported Python version for pull requests and pushes to main, with both the core and MCP packages installed. A separate Python 3.13 packaging job builds both wheels, installs only those wheels into a clean environment, and checks the version import, MCP server import, CLI help, protocol JSON, and passing verify JSON from outside the source checkout.

License

MIT. See LICENSE.