graph-tool GT

GT is graph-tool's binary graph format. Helios reads .gt and zstd-compressed .gt.zst payloads and writes plain .gt payloads. If you need .gt.zst, write .gt and compress it outside Helios.

For the authoritative format description, use graph-tool's own Graph I/O documentation. Helios maps graph-tool graph, vertex, and edge property maps to network, node, and edge attributes when their scalar/vector property-map types can be represented by Helios. Unsupported or lossy property maps are skipped with a warning.

JavaScript

import HeliosNetwork from "helios-network";

const network = await HeliosNetwork.create({ directed: false });
network.addNodes(2);
network.addEdges([[0, 1]]);

await network.saveGT({ path: "./graph.gt" });

const fromGt = await HeliosNetwork.fromGT("./graph.gt");
const fromCompressedGt = await HeliosNetwork.fromGT("./graph.gt.zst");

Helios Web

await helios.loadNetwork(file, { format: "gt" });

const gtBlob = await helios.savePortableNetwork("gt", {
  output: "blob",
  includeVisualization: false,
});

GT is graph-only in Helios Web. Use ZXNet when saving a Helios document with visualization state.

Python

from helios_network import Network, read_gt

network = Network(directed=False, node_capacity=2, edge_capacity=1)
network.add_nodes(2)
network.add_edges([(0, 1)])

network.save_gt("graph.gt")
payload = network.to_gt_bytes()

from_gt = read_gt("graph.gt")
from_gt_zst = read_gt("graph.gt.zst")

Native C

#include <helios/CXNetwork.h>
#include <helios/CXNetworkGT.h>

CXNetworkRef network = CXNewNetworkWithCapacity(CXFalse, 2, 1);
CXNetworkWriteGT(network, "graph.gt");

CXNetworkRef restored = CXNetworkReadGT("graph.gt.zst");
CXFreeNetwork(restored);
CXFreeNetwork(network);

CLI

helios inspect ./graph.gt --format gt --json
helios session start --network ./graph.gt
helios call <sessionId> network.save --json '{"format":"zxnet","outputPath":"./graph.zxnet"}'
helios call <sessionId> network.save --json '{"format":"gt","outputPath":"./roundtrip.gt"}'

Helios writes plain .gt. Use an external zstd compressor when the destination must be .gt.zst.