highs-js API reference

TypeScript declarations for the HiGHS WebAssembly runtime. Initialization is asynchronous; model operations and solves are synchronous. Browser applications should run non-trivial solves in a Web Worker.

Initialization

The default export loads and instantiates the highs.wasm binary. By default the loader fetches it from the same location as the JavaScript module, which works in Node.js and in browsers that serve the .wasm file alongside the loader.

Bundlers (webpack, Rollup, Vite, esbuild, etc.) do not always emit or resolve the .wasm asset automatically, and some rewrite asset URLs in ways that break the default lookup. When initialization fails with a fetch or compile error, pass InitOptions to the loader, with locateFile — return the correct URL for highs.wasm (a CDN, a versioned assets directory, an imported asset URL, etc.).

API surfaces

Search covers every exported method, property, type, constant, and enum. Start with Highs, Model, and ModelData.

Persistent MILP example

This capacitated facility-location model chooses which facilities to open and routes customer demand through the open sites. It combines binary and continuous variables, named sparse model data, options, MIP callbacks, solve information, serialization, mutation, and repeated solves.

import loadHighs from "highs";

const highs = await loadHighs({ locateFile: (file) => `/assets/${file}` });
const { minimize } = highs.constants.objectiveSense;
const { continuous, integer } = highs.constants.variableType;

// x0..x1 open facilities; x2..x7 ship from two facilities to three customers.
const model = highs.createModel({
  modelName: "facility-location",
  numCols: 8,
  numRows: 5,
  sense: minimize,
  colCost: [500, 300, 2, 4, 5, 3, 1, 3],
  colLower: [0, 0, 0, 0, 0, 0, 0, 0],
  colUpper: [1, 1, Infinity, Infinity, Infinity, Infinity, Infinity, Infinity],
  rowLower: [80, 60, 40, -Infinity, -Infinity],
  rowUpper: [80, 60, 40, 0, 0],
  integrality: [integer, integer, continuous, continuous, continuous, continuous, continuous, continuous],
  colNames: ["open-north", "open-south", "n-a", "n-b", "n-c", "s-a", "s-b", "s-c"],
  rowNames: ["demand-a", "demand-b", "demand-c", "north-capacity", "south-capacity"],
  matrix: {
    format: "csc",
    numRows: 5,
    numCols: 8,
    starts: [0, 1, 2, 4, 6, 8, 10, 12, 14],
    indices: [3, 4, 0, 3, 1, 3, 2, 3, 0, 4, 1, 4, 2, 4],
    values: [-200, -200, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
  },
});

try {
  model.options.set({ output_flag: false, mip_rel_gap: 1e-4 });

  const progress = [];
  const firstRun = model.run({
    [highs.constants.callbackType.mipLogging](event) {
      progress.push({
        nodes: event.data.mip_node_count,
        gap: event.data.mip_gap,
      });
      return undefined;
    },
  });

  const firstSolution = model.getSolution();
  const firstPlan = Array.from(firstSolution.colValue, (value, index) => ({
    variable: model.getColName(index),
    value,
  }));

  console.log({
    status: firstRun.modelStatus,
    objective: model.getObjectiveValue(),
    nodes: model.info.get("mip_node_count"),
    dimensions: model.getDimensions(),
    lp: model.exportModel("lp"),
    progress,
    firstPlan,
  });

  // Reuse the native model for a scenario where the south facility is cheaper.
  model.changeColCost(1, 250);
  const secondRun = model.run();
  const secondSolution = model.getSolution();
  console.log(secondRun.modelStatus, secondSolution.colValue);
} finally {
  model.dispose();
}
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What the example exercises

Reference map

• Model data: ModelData, HessianInput, IndexSelection
• Solving and results: Model.run(), Solution, ModelStatusCode
• Advanced analysis: RangingResult, IisResult, Basis
• Configuration and diagnostics: OptionStore, InfoStore, HighsConstants
• Lower-level access: RawRuntimeApi, RawModelApi