Supported file formats

Format	Extension	Open	Export	Carries
Garphield project	.gph	✓	Save	Graph, visual workspace, sets, history, story
GEXF	.gexf	✓	✓	Graph type and attributes
GraphML	.graphml	✓	✓	Graph type and scalar attributes
GML	.gml	✓	✓	Graph data in a plain-text format
Graphviz DOT	.dot, .gv	✓	—	Graph topology and scalar attributes
Node-link JSON	.json	✓	✓	NetworkX-shaped graph data
Compact JSON	.compact.json, .gf.json, or sniffed .json	✓	—	Indexed graph with node/link attributes
graph6	.g6	✓	—	Simple undirected topology only
sparse6	.s6	✓	—	Sparse undirected topology, including loops/parallel links
digraph6	.d6	✓	—	Directed topology, including loops
CSV, TSV, text table	.csv, .tsv, .txt	✓	—	Edge list, flat-table construction, or two-file graph bundle
Plain edge list	.edges, .edgelist, .el	URL	—	Whitespace-delimited endpoints
Matrix Market	.mtx	URL	—	Sparse matrix as an undirected graph
PNG	.png	—	✓	Rendered canvas

Node-link JSON

{
  "directed": false,
  "multigraph": false,
  "graph": {},
  "nodes": [{ "id": "a" }, { "id": "b" }],
  "edges": [{ "source": "a", "target": "b" }]
}

Garphield accepts the current NetworkX edges key and the older links key. Garphield uses a node’s label attribute for display and search when present.

Compact JSON

{
  "nodes": ["Alice", { "label": "Bob", "group": "staff" }, "Carol"],
  "edges": [[0, 1], [1, 2, { "weight": 2 }]],
  "directed": true
}

Each node’s array position is its node ID. A string node is shorthand for a label; an object contains node attributes. Each edge is [sourceIndex, targetIndex] or [sourceIndex, targetIndex, attributes]. directed and multigraph are optional and default to false. Isolates remain explicit in nodes, and duplicate labels are safe because structure uses array positions.

This format is intentionally easy for agents to write and compact in inline URLs. It is import-only. Use node-link JSON when the original node IDs, edge keys, or graph attributes must survive.

graph6 family

graph6, sparse6, and digraph6 are established printable-ASCII topology formats:

• graph6 stores simple undirected graphs compactly, especially dense ones.
• sparse6 stores sparse undirected graphs and can represent loops and parallel links.
• digraph6 stores directed graphs, including loops, with at most one link for each ordered node pair.

Garphield accepts one graph record per load, with or without the standard header. Incremental sparse6 records are not accepted because they depend on a preceding record. These formats carry topology only: imported nodes receive keys and labels 0 through n-1. The loader caps them at 100,000 nodes and 1,000,000 links to prevent tiny declarations from causing unsafe allocations.

For a URL with no matching suffix—especially data:text/plain,...—pass format=graph6, format=sparse6, or format=digraph6 explicitly.

CSV edge list

source,target,weight
a,b,2
b,c,1

Garphield matches source and target headers case-insensitively. Other columns become edge attributes. A table without that header pair opens the graph construction dialog instead.

Two-file CSV graph bundle

Open two CSV or TSV files together from File → Open. Garphield treats the file with source and target columns as the edge table and the other file as the node table. It prefers an id column for the node key; when that column is absent, it infers a key column from the overlap with the edge endpoints. The node table’s remaining columns become node attributes, with label or name supplying the displayed label when available.

Garphield classifies the files by their headers, so names such as links.csv and points.csv work without a special naming convention. You can also open a single-file edge list or construct a graph from a flat table.

Garphield projects

Use .gph for the graph and its visual work. The Python package and embed driver use the same project document. Validate projects against the published GPH schema.