Top API Development & Integration Firms

API development and integration firms build the interfaces that let software talk to other software, and wire up the ones that already exist. Work ranges from designing REST, GraphQL or gRPC APIs for a product or partner program to connecting payment gateways, CRMs, ERPs, shipping carriers, messaging platforms and banking or healthcare systems through their published APIs. Companies hire for it when staff retype data between two systems, when partners want programmatic access, or when a monolith is being split into services.

Compare firms here on the systems they have integrated before, the documentation they hand over, and how they handle authentication, versioning and outages when a third-party API fails.

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We evaluate companies on verified profile data: services, pricing, locations, and portfolio. Client reviews are being collected. We may earn a fee for some placements. How we rank and verify

8,490 Companies

List of the Best API Development & Integration Agencies

Unified Infotech
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Unified Infotech is an established digital transformation partner with 15 years of experience and multiple awards to its name. Our mission is to accelerate business growth through innovative technologies and efficient digital processes. We cater to a diverse clientele, including Fortune 500 companie
Highlights
$25,000+
Min Project Size
$25-49/hr
Avg Hourly Rate
50-249
Employees
New York, New York, Us
Services Provided
40% Custom Web Application Development
30% Mobile App Development (iOS & Android)
20% API Development & Integration
10% E-Commerce Development
AI Summary
“Unified Infotech is a global digital transformation partner delivering tailored web, mobile, and software solutions. With 15 years' experience, it supports businesses through innovative technology and consulting services.”
Xside
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We are a company founded by experienced developers who specialize in creating cutting-edge software while eliminating the usual overhead associated with conventional IT services.
Highlights
$1,000+
Min Project Size
$25-49/hr
Avg Hourly Rate
10-49
Employees
Buenos Aires, Ar
Services Provided
30% Mobile App Development (iOS & Android)
40% Custom Web Application Development
10% Legacy System Modernization
20% API Development & Integration
AI Summary
“Xside is a developer-founded company specializing in innovative software development, delivering advanced solutions efficiently while minimizing traditional IT service overhead.”
Kodansoft
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Clutch users select us because we are a software development firm specializing in B2B digital solutions, including web and mobile applications and IoT. Our expertise lies in developing complex Artificial Intelligence systems and creating web and mobile solutions for business automation, video and au
Highlights
$10,000+
Min Project Size
$25-49/hr
Avg Hourly Rate
10-49
Employees
Daugavpils, Daugavpils Municipality, Lv
Services Provided
40% Custom Web Application Development
30% Mobile App Development (iOS & Android)
20% API Development & Integration
10% E-Commerce Development
AI Summary
“Kodansoft is a software development firm specializing in B2B digital solutions, including AI systems, web, mobile, and IoT applications across diverse industries such as healthcare and finance.”
Vinur Software
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We offer tailored software development and IT outsourcing solutions. Our team of developers creates bespoke software for individuals, startups, as well as small and medium-sized enterprises.
Highlights
$5,000+
Min Project Size
$25-49/hr
Avg Hourly Rate
10-49
Employees
Yerevan, Am
Services Provided
30% Mobile App Development (iOS & Android)
40% Custom Web Application Development
20% API Development & Integration
10% QA & Software Testing
AI Summary
“Vinur Software specializes in custom software development and IT outsourcing, delivering tailored solutions to individuals, startups, and small to medium enterprises across diverse sectors.”
Agile Software Solutions
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We cater to small and mid-sized businesses by providing customized software solutions that eliminate the necessity of employing in-house software engineers. Our leadership team consists of experienced engineers and software developers from various industries, all dedicated to enhancing your speciali
Highlights
$100-149/hr
Avg Hourly Rate
2-9
Employees
Hudsonville, Michigan, Us
Services Provided
25% API Development & Integration
60% Custom Web Application Development
15% QA & Software Testing
AI Summary
“Agile Software Solutions delivers tailored software solutions to small and mid-sized businesses, leveraging experienced industry engineers to enhance specialized software without in-house staffing.”
Zelkom LLC
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𝗭𝗲𝗹𝗸𝗼𝗺 𝗶𝘀 𝗮 𝘁𝗲𝗮𝗺 𝗮𝗱𝗶𝗻𝗴 𝗲𝘅𝗽𝗲𝗿𝘁𝗶𝘀𝗲 𝗶𝗻 𝗥𝘂𝘀𝘁. We create dependable digital solutions, ranging from backend systems and Telegram bots to automation tools and AI integrations. 𝗖𝗹𝗶𝗲𝗻𝘁𝘀 𝗲𝗻𝗴𝗮𝗴𝗲 𝘄𝗶𝘁𝗵 𝘂𝘀 𝘂𝗻𝗱𝗲𝗿 𝗰𝗲𝗿𝘁𝗮𝗶𝗻 𝗰𝗶𝗿𝗰𝘂𝗺𝘀𝘁𝗮𝗻𝗰𝗲𝘀: -
Highlights
$1,000+
Min Project Size
$25-49/hr
Avg Hourly Rate
2-9
Employees
Tbilisi, Tbilisi, Ge
Services Provided
30% Custom Web Application Development
20% API Development & Integration
40% Backend Development
10% Blockchain & Web3 Development
AI Summary
“Zelkom LLC specializes in developing scalable backend systems, Telegram bots, automation, and AI integrations using diverse technologies, supporting startups and B2B globally with reliable digital solutions.”
BETA CORE
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We are a company that focuses on digital construction and transformation. Our passion lies in aiding businesses on their path to innovation, fostering their growth and adaptation in a highly competitive landscape. Over the years, we have assembled a diverse team that merges strategic insight, techno
Highlights
$5,000+
Min Project Size
$25-49/hr
Avg Hourly Rate
10-49
Employees
Bucaramanga, Santander, Co
Services Provided
25% API Development & Integration
60% Custom Web Application Development
15% Mobile App Development (iOS & Android)
AI Summary
“BETA CORE specializes in digital construction and transformation, delivering innovative, user-centric technology solutions that drive business growth and sustainable success in competitive markets.”
Appstronauts
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Address the shortage of IT experts by bringing on senior consultants who can assist you in rapidly scaling your operations and expediting the development process. Our goal is to enhance software development for our partners by providing on-demand access to experienced consultants. We are passionate
Highlights
$10,000+
Min Project Size
$50-99/hr
Avg Hourly Rate
10-49
Employees
Services Provided
20% API Development & Integration
30% Custom Web Application Development
50% IT Staff Augmentation
AI Summary
“Appstronauts provides on-demand senior IT consultants to accelerate software development and scale operations efficiently, focusing on impactful projects that enhance partners' growth and agility.”
Qualifast
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We are a diverse group of professionals focusing on the creation of digital products. We assist both startups and established businesses in developing exceptional technology more swiftly. Our agency intentionally maintains a small size and collaborates with only a select number of clients at once.
Highlights
$25,000+
Min Project Size
$50-99/hr
Avg Hourly Rate
10-49
Employees
Sofia, Sofia, Bg
Services Provided
35% Mobile App Development (iOS & Android)
45% Custom Web Application Development
20% API Development & Integration
AI Summary
“Qualifast is a boutique agency specializing in the swift development of innovative digital products, partnering with startups and established businesses to deliver tailored technology solutions.”
Accesto
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Introducing specialists in PHP modernization. We position ourselves as a trustworthy long-term partner for our clients, taking full accountability for their PHP products and enhancing their scalability and profitability. ✅ 14 years in the industry ✅ Over 100 products developed or improved ✅ Average
Highlights
$50,000+
Min Project Size
$50-99/hr
Avg Hourly Rate
10-49
Employees
Wroclaw, Lower Silesian, Pl
Services Provided
25% Custom Web Application Development
15% API Development & Integration
60% Legacy System Modernization
AI Summary
“Accesto specializes in PHP modernization, improving scalability, performance, and reliability of web applications with expert senior developers and a client-focused approach over 14 years.”

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Top API Development & Integration Firms

List of the Best API Development & Integration Agencies

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