Nessie

Nessie is a plugin-based graph exploration and visualization platform written in Python. It provides a lightweight core runtime, a well-defined API contract, and a growing ecosystem of interchangeable plugins for sourcing, manipulating, and rendering graphs.

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Architecture

┌─────────────────────────────────────────────────────┐
│                  nessie-platform                    │
│         (plugin registry & action dispatcher)       │
└───────────────────────┬─────────────────────────────┘
                        │ depends on
                        ▼
             ┌─────────────────────┐
             │      nessie-api     │
             │  (shared contracts) │
             └─────────────────────┘
                        │
          ┌─────────────┼──────────────┐
          │             │              │
          ▼             ▼              ▼
   Datasource      Visualizer    Manipulation
    Plugins         Plugins        Plugins

The platform discovers and loads plugins at runtime via Python entry points (nessie_plugins). Plugins declare the actions they handle; the platform selects the best one through an optional prioritization plugin.

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Repositories

Core

Repository	Package	Description
Nessie	nessie-platform	Core platform: plugin registry, action dispatcher, and prioritization engine.
nessie-api	nessie-api	Shared models, interfaces, and contracts used by all plugins and the platform.

Interfaces

Repository	Package	Description
nessie-cli	nessie-cli	Command-line interface for Nessie, built with a textX DSL.
nessie-web	nessie-web	Plugin that renders the graph UI in a web browser using Jinja2 templates.
django-web-nessie	—	Django-based web client implementation for Nessie.

Datasource Plugins

Datasource plugins source a graph from an external system and expose it to the platform via the Source_* actions.

Repository	Package	Description
nessie-npm-dependencies-plugin	nessie-npm-dependencies-plugin	Builds a dependency graph starting from a given npm package by querying the npm registry.
nessie-python-datasource-plugin	nessie-python-datasource-plugin	Sources a graph from a Python module or a JSON file.
nessie-relationaldb-datasource-plugin	nessie-relationaldb-datasource-plugin	Loads a graph from a relational database.

Visualizer Plugins

Visualizer plugins render a graph for the user.

Repository	Package	Description
nessie-simple-visualizer-plugin	nessie-simple-visualizer-plugin	Lightweight plugin for simple graph visualization.
neisse-graph-visualiser-block	nessie-block-visualiser	Renders a graph as a blocks view, displaying all node and edge attributes.

Manipulation Plugins

Manipulation plugins transform or filter an in-memory graph.

Repository	Package	Description
nessie-graph-manipulation-plugin	nessie-graph-manipulation-plugin	Provides graph filtering and manipulation operations.

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Getting Started

1. Install the platform and API:

   pip install nessie-platform nessie-api

2. Install the plugins you need, for example:

   pip install nessie-npm-dependencies-plugin nessie-web

3. Use the CLI (see nessie-cli) or embed the platform in your own application:

   from nessie_platform import Platform
   
   platform = Platform()
   graph = platform.get_plugin("Source_Python").handle(action)

   Plugins are discovered automatically via entry points — no manual registration required.

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License

Each repository carries its own license. The core components use the Apache-2.0 license; some plugins use the MIT license. See the individual repositories for details.