tensogram-wasm

WebAssembly bindings for Tensogram via wasm-bindgen.

This crate compiles Tensogram's encode / decode / scan / streaming API to WebAssembly. It is the underlying blob used by the TypeScript package @ecmwf.int/tensogram; most JavaScript callers should use that package rather than the raw bindings here.

Building

cargo install wasm-pack
wasm-pack build rust/tensogram-wasm --target web

This produces rust/tensogram-wasm/pkg/ containing the .wasm, .js glue, and .d.ts TypeScript types.

Usage (from JavaScript, after wasm-pack build)

import init, { encode, decode } from './pkg/tensogram_wasm.js';

await init();

const payload = new Float32Array(100 * 200);
const message = encode(
    { version: 3 },
    [{
        descriptor: {
            type: 'ntensor', ndim: 2,
            shape: [100, 200], strides: [200, 1],
            dtype: 'float32', byte_order: 'little',
            encoding: 'none', filter: 'none', compression: 'none',
        },
        data: payload,
    }],
);

const decoded = decode(message);
console.log(decoded.objectCount());

Supported codecs

lz4, szip (via pure-Rust tensogram-szip), and zstd (via pure-Rust ruzstd). blosc2, zfp, and sz3 are not available in WebAssembly — the underlying libraries have C dependencies that do not compile to wasm32-unknown-unknown.

Installation

cargo add tensogram-wasm

Documentation

• Full documentation: https://sites.ecmwf.int/docs/tensogram/main/
• TypeScript user guide: https://sites.ecmwf.int/docs/tensogram/main/guide/typescript-api.html
• Repository: https://github.com/ecmwf/tensogram

License

Copyright 2026- European Centre for Medium-Range Weather Forecasts (ECMWF).

Licensed under the Apache License, Version 2.0. See LICENSE for details.