# Core Concepts

Monata is a lightweight EDA framework for circuit design. Its main job is to
organize designs, generate reusable views, run simulations through selected
backends, and turn results into measurements, specs, sweeps, and optimization
loops.

## The Monata Mental Model

Monata uses a Library/Cell/View hierarchy:

```text
LibraryRegistry
  Library
    Cell
      schematic view
      testbench view
      netlist view
      symbol view
```

This hierarchy is the center of the user guide. External tools such as ngspice,
Native ngspice execution is the first supported backend path. Other tools may
be part of the broader circuit toolchain, but the Monata user flow
starts from designs and views.

## Framework Responsibilities

| Area | Monata responsibility |
| --- | --- |
| Design organization | Register libraries, discover cells, load views |
| Circuit authoring | Use native Python `monata.netlist` schematic and testbench views |
| Generation | Generate symbols and netlists from schematic metadata |
| Models | Resolve technology model paths and compiled model artifacts |
| Simulation | Build `SimTask` objects and execute them through backends |
| Measurement | Extract metrics from `SimResult` objects |
| Exploration | Run sweeps, corners, Monte Carlo, and optimization |

## Data Flow

A typical design moves through these stages:

1. Create or register a library.
2. Create a cell.
3. Add a schematic view and optional testbench view.
4. Generate symbol and netlist views.
5. Attach models and choose a simulator backend.
6. Create an analysis spec and simulation task.
7. Execute the task and inspect the result.
8. Evaluate measurements and specs.
9. Run sweeps, corners, Monte Carlo, or optimization.

## What Belongs Outside the User Guide

Backend manuals, compiler details, and device-model history live outside the
main user guide:

- simulator behavior: {doc}`../toolchain/ngspice`, {doc}`../toolchain/xyce`
- ngspice backend details: {doc}`../toolchain/ngspice`
- Verilog-A compilation: {doc}`../toolchain/openvaf-osdi`, {doc}`../toolchain/adms`
- model background and compatibility: {doc}`../reference/model-compatibility`