@graphrs/io

Import and export graphs in standard file formats. Powered by igraph's battle-tested parsers via WASM.

npm install @graphrs/io

GraphML

XML-based format with rich attribute support. The standard exchange format for graph tools — supported by Gephi, yEd, Cytoscape, and NetworkX.

import { readGraphML, writeGraphML } from '@graphrs/io';

const graph = await readGraphML(xmlString);
const xml = await writeGraphML(graph);

readGraphML(xml: string): Promise<Graph>

Parse a GraphML XML string into a Graph. Supports directed/undirected graphs, node/edge attributes, and nested <graph> elements.

writeGraphML(graph: Graph): Promise<string>

Serialize a Graph to GraphML XML string.

Example format:

<?xml version="1.0" encoding="UTF-8"?>
<graphml xmlns="http://graphml.graphstudio.org/xmlns">
  <graph id="G" edgedefault="undirected">
    <node id="n0"/>
    <node id="n1"/>
    <node id="n2"/>
    <edge source="n0" target="n1"/>
    <edge source="n1" target="n2"/>
  </graph>
</graphml>

GML

Graph Modelling Language — a human-readable hierarchical format. Used by igraph, NetworkX, and LEDA.

import { readGML, writeGML } from '@graphrs/io';

const graph = await readGML(gmlString);
const gml = await writeGML(graph);

readGML(text: string): Promise<Graph>

Parse a GML string into a Graph.

writeGML(graph: Graph): Promise<string>

Serialize a Graph to GML format.

Example format:

graph [
  directed 0
  node [ id 0 ]
  node [ id 1 ]
  node [ id 2 ]
  edge [ source 0 target 1 ]
  edge [ source 1 target 2 ]
]

DOT (Graphviz)

The Graphviz DOT language. Widely used for graph visualization, supported by dozens of tools.

import { readDOT, writeDOT } from '@graphrs/io';

const graph = await readDOT(dotString);
const dot = await writeDOT(graph);

readDOT(text: string): Promise<Graph>

Parse a DOT format string into a Graph. Supports both graph (undirected) and digraph (directed).

writeDOT(graph: Graph): Promise<string>

Serialize a Graph to DOT format.

Example format:

graph {
  0 -- 1;
  1 -- 2;
  2 -- 0;
}

digraph {
  0 -> 1;
  1 -> 2;
}

Edge List

Minimal plain-text format — one edge per line, space-separated node IDs. The simplest way to represent a graph in a text file.

import { readEdgeList, writeEdgeList } from '@graphrs/io';

const graph = await readEdgeList(text);
const edgeList = await writeEdgeList(graph);

readEdgeList(text: string): Promise<Graph>

Parse an edge list string. Each line defines one edge with two space-separated node IDs.

writeEdgeList(graph: Graph): Promise<string>

Serialize a Graph to edge list format.

Example format:

0 1
1 2
2 3
3 0

Pajek

Pajek format — popular in social network analysis. Supports both vertices and edges sections.

import { readPajek, writePajek } from '@graphrs/io';

const graph = await readPajek(pajekString);
const pajek = await writePajek(graph);

readPajek(text: string): Promise<Graph>

Parse a Pajek .net file string into a Graph.

writePajek(graph: Graph): Promise<string>

Serialize a Graph to Pajek format.

Example format:

*Vertices 4
1 "Node 1"
2 "Node 2"
3 "Node 3"
4 "Node 4"
*Edges
1 2
2 3
3 4

Roundtrip Example

Read a graph from one format, analyze it, then export to another:

import { Graph } from '@graphrs/core';
import { readGraphML, writeDOT } from '@graphrs/io';
import { louvain } from '@graphrs/community';

// Read from GraphML
const graph = await readGraphML(xmlData);

// Analyze
const communities = await louvain(graph);
console.log(`Found ${communities.clusters} communities`);

// Export to DOT for Graphviz visualization
const dot = await writeDOT(graph);

Choosing a Format

Format	Best For	Attributes	Human-Readable	Ecosystem
GraphML	Interop with desktop tools	Yes	Verbose (XML)	Gephi, yEd, Cytoscape
GML	igraph/NetworkX exchange	Yes	Yes	igraph, NetworkX, LEDA
DOT	Visualization with Graphviz	Yes	Yes	Graphviz, d3-graphviz
Edge List	Quick prototyping, data pipelines	No	Minimal	Universal
Pajek	Social network analysis	Limited	Yes	Pajek, UCINet

API Summary

Function	Input	Output	Description
readGraphML	string	Promise<Graph>	Parse GraphML XML
writeGraphML	Graph	Promise<string>	Serialize to GraphML
readGML	string	Promise<Graph>	Parse GML
writeGML	Graph	Promise<string>	Serialize to GML
readDOT	string	Promise<Graph>	Parse DOT/Graphviz
writeDOT	Graph	Promise<string>	Serialize to DOT
readEdgeList	string	Promise<Graph>	Parse edge list
writeEdgeList	Graph	Promise<string>	Serialize to edge list
readPajek	string	Promise<Graph>	Parse Pajek .net
writePajek	Graph	Promise<string>	Serialize to Pajek