Client library for the Draftable document comparison API


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40May 24, 2021Mar 1, 2017Minified + gzip package size for @draftable/compare-api in KB


Draftable Compare API - Node.js Client Library

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A thin JavaScript client for the Draftable API which wraps all available endpoints and handles authentication and signing.

See the full API documentation for an introduction to the API, usage notes, and other reference material.


  • Operating system: Any maintained Linux, macOS, or Windows release
  • Node.js runtime: Any maintained version

Getting started

npm install @draftable/compare-api
  • Instantiate a client
var client = require('@draftable/compare-api').client('<yourAccountId>', '<yourAuthToken>');
var comparisons = client.comparisons;
  • Start creating comparisons
    left: {
        source: 'https://api.draftable.com/static/test-documents/code-of-conduct/left.rtf',
        fileType: 'rtf',
    right: {
        source: 'https://api.draftable.com/static/test-documents/code-of-conduct/right.pdf',
        fileType: 'pdf',
}).then(function(comparison) {
    console.log("Comparison created: %s", comparison);
    // Generate a signed viewer URL to access the private comparison. The expiry
    // time defaults to 30 minutes if the valid_until parameter is not provided.
    const viewerURL = comparisons.signedViewerURL(comparison.identifier);
    console.log("Viewer URL (expires in 30 mins): %s", viewerURL);

API reference

  • All API requests return Promises:
    • Successful calls that return data resolve to Comparison objects
    • Successful calls that return no data resolve to null (e.g. a DELETE request)
    • Calls which fail for any reason will reject the Promise with an Error object

Initializing the client

The package exports a function to create a Client for your API account.

Client provides a comparisons property which yields a ComparisonsClient to manage the comparisons for your API account.

Creating a Client differs slightly based on the API endpoint being used:

// Draftable API (default endpoint)
var comparisons = require('@draftable/compare-api').client(
    '<yourAccountId>',  // Replace with your API credentials from:
    '<yourAuthToken>'   // https://api.draftable.com/account/credentials

// Draftable API regional endpoint or Self-hosted
var comparisons = require('@draftable/compare-api').client(
    '<yourAccountId>',  // Replace with your API credentials from the regional
    '<yourAuthToken>',  // Draftable API endpoint or your Self-hosted container
    'https://draftable.example.com/api/v1'  // Replace with the endpoint URL

For API Self-hosted you may need to suppress TLS certificate validation if the server is using a self-signed certificate (the default).

Retrieving comparisons

  • getAll()
    Returns a Promise which resolves to a list of all your comparisons, ordered from newest to oldest. This is potentially an expensive operation.
  • get(identifier: string)
    Returns a Promise which resolves to the specified Comparison or rejects if the specified comparison identifier does not exist.

Comparison objects have the following properties:

  • identifier: string
    The unique identifier of the comparison
  • left: object / right: object
    Information about each side of the comparison
    • fileType: string
      The file extension
    • sourceURL: string (optional)
      The URL for the file if the original request was specified by URL
    • displayName: string (optional)
      The display name for the file if given in the original request
  • publiclyAccessible: boolean
    Indicates if the comparison is public
  • creationTime: Date
    Time in UTC when the comparison was created
  • expiryTime: Date (optional)
    The expiry time if the comparison is set to expire
  • ready: boolean
    Indicates if the comparison is ready to display

If a Comparison is ready (i.e. it has been processed) it has the following additional properties:

  • failed: boolean
    Indicates if comparison processing failed
  • errorMessage: string (only present if failed)
    Reason processing of the comparison failed

Example usage

var identifier = '<identifier>';

comparisons.get(identifier).then(function(comparison) {
    const visibility = comparison.publiclyAccessible ? 'private' : 'public';
    const status = comparison.ready ? 'ready' : 'not ready';
    console.log("Comparison '%s' (%s) is %s.", comparison.identifier, visibility, status);

    if (comparison.ready && comparison.failed) {
        console.log("The comparison failed with error: %s", comparison.errorMessage);

Deleting comparisons

  • destroy(identifier: string)
    Returns a Promise which resolves on successfully deleting the specified comparison or rejects if no such comparison exists.

Example usage

comparisons.getAll().then(function(oldest_comparisons) {
    console.log("Deleting oldest 10 comparisons ...");
    const deleteStartIndex = Math.max(0, oldest_comparisons.length - 10);

    for (let i = deleteStartIndex; i < oldest_comparisons.length; ++i) {
        const identifier = oldest_comparisons[i].identifier;
        comparisons.destroy(identifier).then(function() {
            console.log("Comparison '%s' deleted.", identifier);

Creating comparisons

  • create(options)
    Returns a Promise which resolves to a new Comparison object.

options consists of the following parameters:

  • left: object / right: object
    Describes the left and right files (see below)
  • identifier: string (optional)
    Identifier to use for the comparison:
    • If specified, the identifier must be unique (i.e. not already be in use)
    • If unspecified, the API will automatically generate a unique identifier
  • publiclyAccessible: boolean (optional)
    Specifies the comparison visibility:
    • If false or unspecified authentication is required to view the comparison
    • If true the comparison can be accessed by anyone with knowledge of the URL
  • expires: Date | string (optional)
    Time at which the comparison will be deleted:
    • Must be specified as a Date object or a string which can be parsed by Date.parse
    • If specified, the provided expiry time must be UTC and in the future
    • If unspecified, the comparison will never expire (but may be explicitly deleted)

options.left and options.right consist of the following parameters:

  • source: buffer | string
    Specifies the source for this side of the comparison:
    • If provided as a buffer, contains the file data (e.g. {source: fs.readFileSync('path/to/file')})
    • If provided as a string, the URL from which the server will download the file (e.g. {source: 'https://example.com/path/to/file'})
  • fileType: string
    The type of file being submitted:
    • PDF: pdf
    • Word: docx, docm, doc, rtf
    • PowerPoint: pptx, pptm, ppt
  • displayName: string (optional)
    The name of the file shown in the comparison viewer

Example usage

var identifier = comparisons.generateIdentifier();


    identifier: identifier,

    left: {
        source: 'https://domain.com/left.pdf',
        fileType: 'pdf',
        displayName: 'Document.pdf',

    right: {
        source: fs.readFileSync('path/to/right/file.docx'),
        fileType: 'docx',
        displayName: 'Document (revised).docx',

    // Expire this comparison in 2 hours (default is no expiry)
    expires: new Date(Date.now() + 1000 * 60 * 120),

}).then(function(comparison) {
    console.log("Created comparison: %s", comparison);

Displaying comparisons

  • publicViewerURL(identifier: string, wait?: boolean)
    Generates a public viewer URL for the specified comparison
  • signedViewerURL(identifier: string, valid_until?: Date | string, wait?: boolean)
    Generates a signed viewer URL for the specified comparison

Both functions use the following common parameters:

  • identifier
    Identifier of the comparison for which to generate a viewer URL
  • wait (optional)
    Specifies the behaviour of the viewer if the provided comparison does not exist
    • If false or unspecified, the viewer will show an error if the identifier does not exist
    • If true, the viewer will wait for a comparison with the provided identifier to exist
      Note this will result in a perpetual loading animation if the identifier is never created

The signedViewerURL function also supports the following parameters:

  • valid_until (optional)
    Time at which the URL will expire (no longer load)
    • Must be specified as a Date object or a string which can be parsed by Date.parse
    • If specified, the provided expiry time must be UTC and in the future
    • If unspecified, the URL will be generated with the default 30 minute expiry

See the displaying comparisons section in the API documentation for additional details.

Example usage

var identifier = '<identifier>'

// Retrieve a signed viewer URL which is valid for 1 hour. The viewer will wait
// for the comparison to exist in the event processing has not yet completed.
var valid_until = new Date(Date.now() + 1000 * 60 * 60)
var viewerURL = comparisons.signedViewerURL(identifier, valid_until, true);
console.log("Viewer URL (expires in 1 hour): %s", viewerURL);

Utility functions

  • generateIdentifier()
    Generates a random unique comparison identifier

Other information

Browser support

This library is designed primarily for server-side usage. Usage in web browsers (client-side) is not currently supported.

Calling the Draftable API via client-side JavaScript is generally discouraged as this implies sharing API credentials with end-users.

Self-signed certificates

If connecting to an API Self-hosted endpoint which is using a self-signed certificate (the default) you will need to suppress certificate validation. This can be done by setting the NODE_TLS_REJECT_UNAUTHORIZED environment variable to 0.

See the below examples for different operating systems and shell environments. Note that all examples only set the variable for the running shell and it will not persist. To persist the setting consult the documentation for your shell environment. This should be done with caution as this setting suppresses certificate validation for all connections made by the Node.js runtime!

(ba)sh (Linux, macOS, WSL)




Command Prompt (Windows):


Setting this environment variable in production environments is strongly discouraged as it significantly lowers security. We only recommend setting this environment variable in development environments if configuring a CA signed certificate for API Self-hosted is not possible.

Static type checking

We use Flow for static type checking:

  • All source code has Flow type annotations
  • The published package has type information available in dist/flow

If you're using Flow you can enable type checking by adding the following snippet to your project's .flowconfig:


If you find any bugs or have a feature request, please open an issue on github!

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