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    This library was designed to be used in SPA framework wrappers for the FingerprintJS Pro Javascript Agent. It also has several built-in caching mechanism that are optimized according to the official recommendations. If just need the JS agent, you can use it directly, without this wrapper. If you're looking for a dedicated React integration, you can find it here.

    This SDK works with FingerprintJS Pro, it will not work with the OSS version! Learn more about the difference between Pro and OSS. If you'd like to have a similar SPA wrapper for the OSS version of FingerprintJS, consider raising and issue on our issue tracker.

    Table of Contents


    This library uses FingerprintJS Pro under the hood, you can view the document for the core technology.


    Using npm:

    npm install @fingerprintjs/fingerprintjs-pro-spa

    Using yarn:

    yarn add @fingerprintjs/fingerprintjs-pro-spa

    Getting Started

    FingerprintJS public API key

    In order to identify visitors you'll need a FingerprintJS Pro account (you can sign up for free).

    Creating the client

    Create an FpjsClient instance before rendering or initializing your application. You should only have one instance of the client.

    import { FpjsClient } from '@fingerprintjs/fingerprintjs-pro-spa';
    // It can receive mulptiple parameters but the only required one is `loadOptions`, which contains the public API key
    const fpjsClient = new FpjsClient({
      loadOptions: {
        apiKey: "your-fpjs-public-api-key" // insert your public api key from the dashboard here

    You can learn more about different load options here:

    1 - Init the JS agent

    Before you start making identification requests to the FingerprintJS Pro API, you need to initialize the Agent to allow it to gather browser signals. Make sure the initialization has been completed before calling the getVisitorData method to avoid errors.

    // with async/await
    await fpjsClient.init()
    const visitorData = await fpjsClient.getVisitorData()
    // with promises
    const visitorData = fpjsClient.init().then(() => {
      return fpjsClient.getVisitorData()

    2 - Calling an API

    The getVisitorData method returns visitor identification data based on the request options []. The second parameter ignoreCache will make sure that a request to the API be made even if the data is present in cache.

    // with async/await
    const visitorData = await fpjsClient.getVisitorData({ extendedResult: true })
    // with promises
    const visitorData = fpjsClient.getVisitorData({ extendedResult: true }).then((visitorData) => {
      // use visitor data in your fraud prevention logic
      checkIfFingerprintIsFraudulent(visitorData.visitorId) // this method is just an example, this SDK doesn't actually supply it


    The SDK can be configured to cache the visitor data in memory, in session storage or in local storage. The default is in session storage. This setting can be controlled using the cacheLocation option when creating the Fpjs client.

    To use the session storage mode, no additional options need are required as this is the default setting. To configure the SDK to cache data using local storage, set cacheLocation as follows:

    const fpjsClient = new FpjsClient({
      loadOptions: {
        apiKey: "your-fpjs-public-api-key"
      cacheLocation: 'localstorage'

    Or if you are using TypeScript:

    const fpjsClient = new FpjsClient({
      loadOptions: {
        apiKey: "your-fpjs-public-api-key"
      cacheLocation: CacheLocation.LocalStorage

    Cache keys are formed based on the combination of the GetOptions, so, for example, API responses for calls with extendedResult: true and extendedResult: false will be stored independently.

    Creating a custom cache

    The SDK can be configured to use a custom cache store that is implemented by your application. This is useful if you are using this SDK in an environment where a different data storage is more convenient, such as potentially a hybrid mobile app.

    To do this, provide an object to the cache property of the SDK configuration.

    The object should implement the following functions. Note that all of these functions can optionally return a Promise or a static value.

    Signature Return type Description
    get(key) Promise or object Returns the item from the cache with the specified key, or undefined if it was not found
    set(key: string, object: any) Promise or void Sets an item into the cache
    remove(key) Promise or void Removes a single item from the cache at the specified key, or no-op if the item was not found
    allKeys() Promise<string[]> or string [] Returns the list of all keys. By default the keys we use are prefixed with @fpjs@client@ but you can pass your own custom prefix as an option when you create the FpjsClient

    Note: The cache property takes precedence over the cacheLocation property if both are set. A warning is displayed in the console if this scenario occurs.

    We also export the internal InMemoryCache, LocalStorageCache, SessionStorageCache and CacheStub implementations, so you can wrap your custom cache around these implementations if you wish.

    Cache time

    Fpjs client receives cacheTimeInSeconds as one of the options. In order to ensure high identification accuracy we recommend that the visitor data is not cached for longer than 24 hours. For that reason, if you pass a value higher than 86400 (60 * 60 * 24), the FpjsClient constructor will throw an error.

    Support + Feedback

    For support or to provide feedback, please raise an issue on our issue tracker.

    What is FingerprintJS?

    FingerprintJS Pro is the fraud detection API for your business

    FingerprintJS Pro is a combination of a JavaScript agent that runs in the browser and a server-side storage and API system that securely identifies visitors and stores all the information you need to detect fraud.

    JavaScript agent

    FingerprintJS Pro does not calculate fingerprints in the browser. Instead, it uses a lightweight JavaScript agent that collects multiple device signals and sends them to our servers. This helps prevent reverse engineering and spoofing of an identifier by advanced bots. The agent is hosted at edge locations around the world. It is only 12 KB in size and 20 ms away from your users.

    Server-side identification system

    Server-side identification system provides a platform that processes and stores page views and events to identify your website visitors. It also provides many helpful features that are explained in more detail on dedicated documentation pages.

    Learn more on our official documentation page


    This project is licensed under the MIT license. See the LICENSE file for more info.


    npm i @fingerprintjs/fingerprintjs-pro-spa

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