Using chrome extension apis in typescript

As of typescript 2 (or 2.x, not sure), you should import the chrome types from @types.

in package.json:

"devDependencies": {
    ...
    "@types/chrome": "0.0.35", // or just npm install --save-dev @types/chrome

And in tsconfig:

    "types": [
        //(various types, e.g. jquery, core-js),
        "chrome"
    ]