Power!

Power! is a powertrain modeling and experimentation project built around a cross-platform C# physics core, a Unity 3D studio, and agent-friendly MCP interfaces. Models, solvers, experiments, and presentation have separate responsibilities. Agents can construct models, inspect diagnostics, branch experiments, and evaluate physical evidence through explicit contracts.

The public repository is Water-Run/Power. The owner resumed the native migration on 2026-09-10. The archived native prototypes now use Zig; the managed application baseline and remaining full-powertrain work are recorded in the roadmap.

Technology

Managed versions were pinned on 2026-09-07; the separate native Zig toolchain was pinned on 2026-09-11:

Layer	Version and responsibility
Unity 3D	Unity 6.6 / 6000.6.0f1, desktop studio
Rendering, input, UI	URP 17.6.0, Input System 1.20.0, UI Toolkit
C# tooling	.NET 10 SDK 10.0.400 / C# 14, core, CLI, agent services, and build tools
Unity-facing assemblies	.NET Standard 2.1, compiled from the same core and asset source
Agent transport	Official MCP C# SDK 2.2.0, stdio, committed dependency lock files
Native prototypes	Zig 0.15.2, separate research library with the preserved binary ABI

Sources: Unity release notes, .NET 10 downloads, MCP SDK.

Unity's own compiler supports C# 9, with .NET Standard 2.1 as its default API profile. The external .NET SDK compiles modern C# into Unity-compatible assemblies; scripts inside Unity/Assets use C# 9 syntax. A Unity Player does not require a separate .NET 10 installation. See Unity's compiler support and API compatibility documentation.

Build and verify

Install the pinned .NET SDK and Python 3.12 or newer, then install Zig and run from the repository root on Windows, macOS, or Linux (python on Windows):

python3 tools/InstallZig.py
dotnet run --file tools/Build.cs -p:UseSharedCompilation=false -- verify

This builds the solution serially, exports Unity model assets, runs the core and agent checks, exercises an actual MCP server process, and verifies the Zig runtime, shared-library hosts, Python ABI and original numerical baseline. It writes experiment and migration reports under artifacts/reports. The source audit rejects C/C++ implementation files and headers, plus Lua source, bytecode and packages. Build servers and concurrent compilation are disabled inside the build tool to reduce memory pressure. The local .cache/dotnet/dotnet executable can also be used when the pinned SDK is installed there; caches are excluded from Git.

The current increment passed 38/38 managed checks, 26/26 Unity-facing assembly checks, and 6/6 MCP integration groups on Windows, macOS, and Linux. See the CI run and validation record. The assembly checks run under .NET 10; actual Unity Editor, Play Mode, rendering, and IL2CPP validation remain pending.

Run an experiment directly:

dotnet run --project src/Power.Cli -c Release -- assets/labs/electrothermal.power.json --output artifacts/reports/electrothermal.json

CLI exit codes are 0 for a passing experiment, 2 for failed KPIs or replay checks, and 1 for invalid input or execution errors. Model documents specify units, fixed nanosecond ticks, input events, and KPI bounds. Reports include source hashes, model fingerprints, runtime information, fidelity, channels, replay evidence, and energy residuals.

Unity studio

1. Run dotnet run --file tools/Build.cs -p:UseSharedCompilation=false -- build. This creates the Core and Assets assemblies in Unity/Assets/Plugins and three sample .powerasset files in Unity/Assets/Generated/Resources.
2. Add the repository's Unity directory to Unity Hub and select 6000.6.0f1.
3. Allow package resolution and script import to finish. Initial project preparation generates URP and material assets.
4. Open Assets/Scenes/PowerLab.unity, or choose Power > Open laboratory, then enter Play Mode.

The scene code builds rotors, thermal nodes, connections, and input controls from the imported model. It supports pause, reset, and saved experiments with events applied at exact simulation ticks. The default electrothermal experiment runs a ten-second braking and recovery sequence; ThermalNetwork.powerasset contains a thermal exchange experiment with no external inputs. Use Open in Studio in a model asset's Inspector to select it.

SealedCylinder.powerasset adds a compression/expansion experiment and a schematic moving piston. Its gas state, crank torque and energy channels use the same model semantics as CLI and MCP. The cylinder documentation records equations, solver limits and missing engine behavior.

Export another model after building:

dotnet src/Power.Cli/bin/Release/net10.0/Power.Cli.dll export assets/labs/electrothermal.power.json --name "My laboratory" --output Unity/Assets/Models/MyLaboratory.powerasset

The importer checks integrity, recompiles the model, and verifies its fingerprint. See the asset format. Drag to orbit and scroll to zoom. Each FixedUpdate advances at most 2,000 complete ticks: 20 ms for the default model, or 14 ms for the 7 ms thermal model. Physics never reads rendering deltaTime; this presentation schedule does not guarantee wall-clock real-time operation for every tick size.

Set POWER_UNITY_EDITOR to the Editor executable and run:

dotnet run --file tools/Build.cs -p:UseSharedCompilation=false -- unity-test

This is the separate entry point for actual Editor and Play Mode checks. Unity has not been installed or exercised in the current development environment, and no validated Player build is available yet.

Agent interface

After building, launch this executable as a client's stdio MCP server:

dotnet /absolute/path/to/Power/src/Power.Mcp/bin/Release/net10.0/Power.Mcp.dll

The service exposes twelve tools with input and output schemas: capabilities, model schema, example, validation, experiments, asset export, session creation, input changes, time advancement, snapshots, branching, and disposal. Protocol output uses stdout and logs use stderr. Agents can operate the headless core without controlling the Unity UI or calling a model provider inside the physics loop.

The agent API documents client configuration and operation sequences. The core provides TryCompile, discoverable channels, Fork, cancellation, and atomic rollback. The MCP workspace adds revision checks and compact reports.

Scope

The current executable C# models include rotational inertia, elastic shafts with positive or negative ratios, RL DC motors, torque sources, thermal capacities, heat-conduction networks, and sealed adiabatic cylinders with slider-crank geometry. They share coupled integration and an energy ledger. All sample parameters are marked unverified.

The complete engine, intake, combustion, exhaust, DCT/AT, hydraulic, ECU/TCU, and calibrated powertrain objectives remain open. Earlier native prototypes and tests have been ported to Zig in legacy/native; their functionality has not all been migrated to C#. All 38 C source/header files were replaced, with original hashes and Git provenance in the migration manifest. Research for EA211 DJS + DQ200 and PSA EC5 + AT8 remains in assets/samples, with its evidence and calibration boundaries intact.

The native Zig boundary retains the versioned binary ABI without introducing a native dependency into the C#/Unity application. Native migration completion is separate from full powertrain functionality, vehicle calibration and Unity Editor validation.

See the architecture, roadmap, and validation record. Existing documents may retain their original language; new documentation and updates use English.

License

Original Power! material is licensed under GPL-3.0-or-later with the Unity Linking Exception. Read COPYING.NOTICE, the unmodified GPLv3 text, and the exception together.

The exception permits the specified Unity combination while keeping Power! and its modifications under GPL requirements. Unity and other third-party software retain their own licenses; the exception grants no rights held by their authors. See third-party notices. Preserve the applicable license, copyright, and notice files when distributing source or binaries.