Custom API Development Services Company


Unleash the potential of your business data insights accumulated across multiple platforms in real-time with high-performance, custom-built, and agile-focused APIs.

As you collaborate with our custom API development services company for your API-based solutions, you can amplify seamless connectivity with software components, application systems, and custom API integration tools.

From simple, straightforward to complex, multi-faceted API integrations, we are with you shoulder-to-shoulder throughout the project lifecycle. Get catered to your custom API development requirements with our prowess in API development, customization, and integration with minimal code at a quick pace and affordable price.

  • Powerhouse of custom API development solutions for travel, education, healthcare, real estate, finance, and whatnot
  • Our company offers tailor-made API design services and API implementation solutions to clients worldwide, including those from the USA, UK, and Europe
Our Custom API Development Services and Professional Expertise at
Custom API Development & Integration Services
Custom API Integration & REST API Services
Cloud API Development & API Design Services
Mobile / Web API Interface Support Services
API QA & API Automation Integration Services

From Custom API Development to API Deployment, We Can Be Your Go-to API Solutions Provider/ API Integration Services Partner

Simplify and automate your complex business processes with our custom-built API development & integrations solutions. Eliminate siloed applications, drive your business into an API-based model, and experience the below.

  • Enhance productivity through automated workflows
  • Ignore the need for writing complex code structures
  • Build essential apps without breaking the bank
  • Optimal result-oriented delivery on-time
Custom API Development Services Company - ColorWhistle
WordPress services, digital strategy and SMM awards - ColorWhistle (techbehemoths) WordPress services,digital strategy and SMM awards - ColorWhistle (techbehemoths 2023)

Gear Up Your Wheels on the Roads of API Development and Reap Boundless Advantages With Our Intuitive, Highly-scalable, Full-fledged, Budget-friendly, Enterprise-grade API Services

Our Process

Unlock the Power of Custom API Development Services and Third-Party API Integration Services to Enhance Your Business with These Key Benefits
  • API consulting services with strategies and expertise
  • Custom API development with right tools & best API code practices
  • Build custom API solutions ensuring security and scalability
  • Go easy with Third party API integration with our custom API development
  • Payment Gateways, Maps, Social Media, Web and Hybrid APIs we cater to service all
  • Efficient API testing and API automation services
Custom API Development and API Integration Services – ColorWhistle

We have API integration services ranging from marketing-centric offerings such as HubSpot, Marketo, and SendGrid; Sales & CRM API Integrations including Salesforce, Copper, and Keap; Workflow Automations for Zapier, or GetResponse plus REST APIs supporting WordPress – Rezdy API & Wetu API, alongside support for Google Maps plus other associated Google APIs!

Ready for a Partnership Handshake With ColorWhistle’s API Integration Services? – Industries we Work for

Are you looking for a one-stop solution for all your API-related requirements? Get in touch with our custom API developers to enrich the services you offer to your end clients.

Get high-performing, dependable, & scalable APIs for businesses belonging to travel, hotel & restaurant, education, healthcare, and real estate. There are no restraints that we work only with these niche-based businesses, our passion for API development and dedication towards working with clients are incredibly encouraging us to deliver values to varied industries.

White Label Digital Agency - Industries We Work For

APIs That Yield Results

Custom develop APIs for the modern AI world

Are You an Agency Looking for B2B Outsourcing Partnership for Your API Development Services?

If yes, we can understand your concerns. We can be your reliable, young, & energetic troops of B2B partners catering to all your API requirements. With that being said, we take up the responsibility and work on your end-client’s projects. It’s no more your project, we see it as our own. We appoint a dedicated team to work solely on your API projects whether it is scratch development, customization, integration, or anything related to API services.

Would You Like to Partner with a White-label API Integration Services Agency?

If your answer is yes, then you have landed in the right place. At ColorWhistle, we offer comprehensive white-label services for custom API development. We abide by all terms and conditions of white-label services, on that line, we sign proper NDAs therewith, and we will not be exposing our brand anywhere without your knowledge nor negotiating with your clients. You can experience a secure process throughout the API development journey.

Need Guidance from Professional API Development Services Agencies for Your Business?

If this is your need, we can serve your API requirements. At ColorWhistle, we are so much passionate about API development, and more than all, we always love delivering exactly what our clients require. And, we actually mean it. We understand your pain-points and only after getting better clarity on your API requirements, our developers will keep the ball rolling.


Payment Gateway API Integration Services

We offer payment gateway integration service using the famous gateways such as PayPal, Stripe,, Google Checkout, PayU, BillDesk, and CCAvenue.

Example of Payment Gateway API Integration Combinations

  • Stripe + Wave
  • Stripe + Mailchimp
  • Stripe + Slack
  • Stripe + Email by Zapier
  • PayPal + Mailchimp
  • PayPal + Slack
  • PayPal + Salesforce
Custom API Development and Integration Services - ColorWhistle

Sales API Integration Services

Integrate sales API into your custom software to manage your CRM. Some common integrations that we do are HubSpot, Salesforce, Marketo, Constant Contact, and more.

Example of Sales API Integration Combinations

  • Facebook lead ads + HubSpot
  • Pipedrive + Slack
  • Facebook lead ads + Salesforce
Custom API Development and Integration Services - ColorWhistle

Social Media API Integration Services

We offer Social Media API integration services for Facebook, Twitter, LinkedIn, Google+, Instagram, Pinterest, YouTube, Vimeo, Bebo, and much more to help you reach a large amount of audience.

Example of Social Media API Integration Combinations

  • Instagram + Facebook Pages
  • Facebook Pages + LinkedIn
  • Facebook Pages + Slack
  • Twitter + SMS by Zapier
  • LinkedIn Lead Gen Forms + Salesforce
  • LinkedIn Lead Gen Forms + HubSpot
Custom API Development and Integration Services - ColorWhistle

Travel API Integration Services

Our professional API developers can work with channel management software and GDS/API/XML integration for flights, hotels, cruise, navigation, weather, and more.

Example of Travel API Integration Combinations

  • Website + TripAdvisor content
  • Website + Public transportation
  • Website + Travel management and planning
Custom API Development and Integration Services - ColorWhistle

Marketing API Integration Services

We integrate marketing APIs such as LinkedIn Marketing Developer, Google Adwords, Clearbit, FullContact, MailChimp, Hootsuite, other social login gateways, and more to manage your audience and find new customers.

Example of Marketing API Integration Combinations

  • Delighted + Slack
  • Delighted + Prodsight
  • Typeform responses + Google Sheets
Custom API Development and Integration Services - ColorWhistle

Marketplace API Integration Services

Our API developers in India can help you find the right API marketplaces like Zapier, Integratedly, MuleSoft’s Anypoint, or Integromat and seamlessly integrate your software into them.

Example of Marketplace API Integration Combinations

  • Facebook Marketplace + Hubspot
  • Bigcommerce + HubSpot
Custom API Development and Integration Services - ColorWhistle

Healthcare API Integration Services

We offer API integration services for patient registration, scheduling, finances & billing, insurance, clinical, ancillary, public health, and IOT while supporting healthcare information standards such as HL7, FHIR, HL7v2, HL7v3, and MLLP.

Example of Healthcare API Integration Combinations

  • Mail Chimp + Acuity Scheduling
  • Acuity Scheduling + Google Calendar
  • Acuity Scheduling + WordPress
Custom API Development and Integration Services - ColorWhistle

Communication / Chat API Integration Services

We can integrate communication APIs for SMS (Two-Way SMS API, SIP Trunking Number Discovery) and e-mail (SendGrid, ZeroBounce, etc) to attract, convert, and retain customers.

Example of Communication API Integration Combinations

  • Google Sheets + SendGrid
  • Gravity Forms + SendGrid
  • Facebook Lead Ads + SendGrid
  • Mailchimp + SendGrid
  • ClickFunnels + Mailchimp
  • Google Forms + Mailchimp
  • Wave + Mailchimp
Custom API Development and Integration Services - ColorWhistle

GraphQL API Development and API Integration Services

With GraphQL (data query and manipulation language for APIs), we can improve your application’s performance and scalability and provide the requested data.

Custom API Development and Integration Services - ColorWhistle

Education API Integration Services

Our API developers can create a great learning environment for students by integrating APIs such as communication, collaboration, whiteboard, virtual classroom, and content sharing.

Example of Education API Integration Combinations

  • Teachable + Active Campaign
  • Teachable + Custom reminders
  • Teachable + Convertkit
Custom API Development and Integration Services - ColorWhistle

CMS Website REST API Development, API Integration Services

Our company offers secure CMS platform integration via API connectors. We connect to WordPress, Joomla, Drupal, HubSpot, Kentico, Magento, Sitecore, Contentful, Sitecore, Typo3, and more.

Example of CMS API Integration Combinations

  • PlanSo Forms for WordPress + Google Sheets
  • PlanSo Forms for WordPress + HubSpot
  • WordPress + Facebook Pages
  • WordPress + LinkedIn
  • WordPress + Slack
  • HubSpot + Wave
  • Google Contacts + HubSpot
Custom API Development and Integration Services - ColorWhistle

E-commerce API Integration Services

Our team can integrate e-commerce APIs such as security, price comparison, shipping, site search, payment handling, and store API integration that are aimed at enhancing the customer shopping experience.

Example of E-commerce API Integration Combinations

  • Amazon Seller Central + Salesforce
  • Dropbox + Amazon S3
  • WooCommerce + Xero
Custom API Development and Integration Services - ColorWhistle

Google API Integration Services

We offer API integration services for the most popular Google APIs such as maps, chart, checkout, translate, search, Webmaster tools, analytics, AdWords, and YouTube.

Example of Google API Integration Combinations

  • YouTube + Discord
  • YouTube + Slack
  • Dropbox + YouTube
  • Stripe + Google Analytics
Custom API Development and Integration Services - ColorWhistle

Accounting API Integration Services

Our API developers can integrate with the leading accounting solutions, like QuickBooks, Xero, MYOB, Freshdesk, Sage, Fortnox, and more.

Example of Accounting API Integration Combinations

  • Freshdesk + Slack
  • Freshdesk + Trello
  • Freshdesk + Asana
  • Stripe + Xero
  • Xero + Digest by
  • Zapier + Slack
Custom API Development and Integration Services - ColorWhistle

Real Estate API Integration Services

We provide top API integration for real estate professionals to get access to MLS and IDX data from providers such as Zillow,, SimplyRETS,, Walk Score, DataNerds Property, Yelp Fusion, Rets Rabbit, and more.

Example of Real Estate API Integration Combinations

  • Zillow + WordPress
  • Mailchimp + Zillow
  • IDX, MLS + WordPress
Custom API Development and Integration Services - ColorWhistle

Our Client Reviews in

“They had a very professional approach across the board which included: clear, concise and timely communications.”

We take pride in the fact that our reviews from clients speak for themselves. Our ratings are always top-notch and we’re happy to answer any questions you might have about them!

Get Access to Our Case Studies and Ebooks

Don’t just take our word for it – see yourself how our custom API solutions have helped our clients.


Frequently Asked Questions About Our Custom API Development Services

In simple words, APIs are Application Programming Interface that acts as an intermediary connecting the applications and software systems in your business.

As a dedicated team of API developers, we will guarantee you an optimal turnaround time. But, before we give you an accurate timeframe for your custom API development, we need to look after your requirements. Only when we have a clear vision of what are your expectations and objectives, we will be able to frame a timeline.

From our POV, we would say, ‘customization is the key’ in API development. Only when you build a custom API tailor-made for your requirements, otherwise, it will not serve your goals.

Our API development & integration services approximately starts from $400. This is an average cost. Depending on your needs, it may vary. Feel free to reach out to our team and let us know your API requirements, so that we can come up with a custom quote.

Certainly! Once after signing up the contract, we allocate a dedicated team involving a project manager and developer to handle your API projects. The corresponding developer will regularly communicate with you about the updates.

As you partner with our API development team, you’ll get custom-built APIs at a cost-effective budget in a quick turnaround time. And moreover, you will get access to collaborate with an enthusiastic team of API players, who are highly collaborative, empathetic, and passionate about API development.

Digital Agency Pricing Model - ColorWhistle

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In order to provide accurate quotes and relevant suggestions for technology, it is helpful for us to have a clear understanding of the specific services you are seeking. At ColorWhistle, we take pride in delivering accurate quotes in a timely manner.

To assist us in this process, do provide as many details as possible about your project in the ‘message’ section.


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