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How to Combine Two API Response: A Step-by-Step Guide

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In today’s digital age, APIs (Application Programming Interfaces) have become an integral part of software development. APIs allow different software systems to communicate and share data, enabling developers to build complex and dynamic applications. However, there may be situations where a developer needs to combine responses from two or more APIs. This post will provide a step-by-step guide on how to merge two API responses effectively.


APIs are like the backbone of modern web services. They provide a standardized way for applications to communicate with each other, and they make it possible for data to be exchanged between different software systems seamlessly. But what happens when you need to integrate data from two separate APIs? How can you merge two API responses into one? These are some of the questions that this blog post aims to answer.

Importance of Combining API Responses

Combining API responses can be useful in various scenarios.When working with APIs, developers often need to fetch data from multiple sources. This is where making two different API calls becomes relevant. Each API call requires a unique API URL, which serves as the address to access a specific API endpoint.

An API endpoint represents a specific resource or functionality provided by the API. For instance, if you’re building an application that pulls data from multiple sources, you might need to merge the responses from these sources to present a unified view to your users. Moreover, combining API responses can help to enrich the data you’re working with, providing more comprehensive insights.

It also allows for more efficient data processing and reduces the number of API calls, which can lead to better performance and lower costs. Response time distribution can provide insights into the performance of an API. For example, an API might have a 95th percentile response time of 500 milliseconds, indicating that 95% of API calls are responded to within that time frame.

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Step 1: Understand the API Responses

Analyze The Structure And Format Of Each Api Response

The first step in merging two API responses is to understand the structure and format of each response.The average response time for APIs can vary across industries and use cases. However, a general guideline is to strive for response times of around 200-300 milliseconds for a smooth user experience.

Different APIs may return data in different formats, such as JSON or XML. Additionally, the structure of the data can vary significantly between APIs. Therefore, it’s crucial to analyze each API response thoroughly to understand how the data is organized and structured. Merge data by combining the JSON arrays obtained from each API call.

JSON arrays are collections of values enclosed in square brackets ([]). They allow us to store multiple sets of data within a single variable. By concatenating or appending the arrays, we can merge the data obtained from the different API calls.

Identify Common Data Fields And Variables

Once you’ve analyzed the structure and format of the API responses, the next step is to identify the common data fields and variables that can be used to merge the responses. These could be identifiers like user IDs, product IDs, timestamps, or any other field that is shared between the two APIs.

Service Level Agreements (SLAs) often specify the maximum allowable response time for an API. Organizations strive to adhere to SLAs to ensure consistent and reliable performance. A common SLA target is to have 99% of API responses within a specific time, such as 500 milliseconds.

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Step 2: Extract the Required Data

Determine Which Data From Each Api Response Needs To Be Combined

After identifying the common fields, determine which data from each API response needs to be combined. This largely depends on the requirements of your application. For example, if you’re building a weather app that gets data from two different weather APIs, you might need to combine temperature data from both APIs to get a more accurate reading. API response time contributes to overall system latency. For instance, studies have shown that even a 100ms increase in response time can lead to decreased user satisfaction and usage.

Use Appropriate Methods Or Tools To Extract The Required Data

There are several methods and tools available to extract the required data from API responses. Some popular options include using programming languages like Python or JavaScript, using API management platforms like APIMatic, or using data manipulation libraries like Pandas in Python. Choose the method or tool that best fits your needs and skill level.

Step 3: Transform and Merge the Data

Ensure That The Data From Both Api Responses Are Compatible

Before merging the data, ensure that the data from both API responses are compatible. This means that the data should be in the same format and have the same structure. If this is not the case, you might need to transform the data to make it compatible.

This can involve converting data types, changing the format of dates or times, or restructuring the data. Different API endpoints or methods might have varying response times. Monitoring and analyzing response times for individual endpoints can help identify bottlenecks or performance issues in specific areas of an API.

Apply Any Necessary Transformations Or Formatting To The Data

If the data requires transformation, apply any necessary transformations or formatting to the data. For example, if one API returns dates in the format “YYYY-MM-DD” and another API returns dates in the format “MM/DD/YYYY”, you would need to transform one of these to match the other.

Merge The Data Into A Single Response Or Dataset

Once the data is compatible and properly formatted, it’s time to merge the data into a single response or dataset. There are many ways to do this, depending on the tools you’re using. For example, if you’re using Python, you can use the pandas library to merge data frames.

If you’re using JavaScript, you can use the spread operator to merge objects. Through performance optimization techniques, organizations aim to improve API response times. For example, caching, request batching, and load balancing are commonly employed strategies to reduce response times and improve overall efficiency.

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Step 4: Handle Errors and Exceptions

Implement Error Handling Mechanisms For Cases Where Api Responses Are Incomplete Or Inconsistent

It’s important to implement error-handling mechanisms to handle cases where API responses are incomplete or inconsistent. This can include checking for null or missing values, validating data types, and handling exceptions. Proper error handling can prevent your application from crashing and can improve its reliability and robustness.

Include Appropriate Error Messages Or Fallback Options

In addition to implementing error-handling mechanisms, it’s also a good idea to include appropriate error messages or fallback options. This can help users understand what went wrong in case of an error and can provide alternatives or suggestions for how to proceed.

Step 5: Test and Validate the Combined API Response

Perform Testing To Ensure The Combined Api Response Is Accurate And Complete

After merging the API responses, it’s essential to perform thorough testing to ensure the combined API response is accurate and complete. This includes checking that all required data fields are present, the data is correctly formatted, and the merged data is consistent with the original API responses.

Validate The Data Against Expected Results Or Requirements

Finally, validate the data against expected results or requirements. This can involve comparing the merged data with a known correct result, or checking that the data meets certain requirements or constraints. Data validation is a critical step in ensuring the accuracy and reliability of your application.

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Final Thoughts

Merging two API responses may seem like a daunting task, but with the right approach and tools, it can be accomplished effectively. The key is to understand the structure of the API responses, identify common fields, extract the necessary data, transform and merge the data, handle errors, and validate the results. By following these steps, developers can integrate data from multiple APIs, enrich their applications with diverse data sources, and provide a better user experience.

In today’s fast-paced world, efficiency is key to success. Streamlining processes and automating workflows can save time, increase productivity, and reduce human error. One effective way to achieve this is by using three columns and code functions. To automate workflow, one can leverage code functions.

Remember, the goal is not just to combine API responses but to do so in a way that enhances your application and provides value to your users. So, make sure you understand the needs of your users and the purpose of your application before you start merging API responses. Happy coding!

Last Updated on October 10, 2023 by Priyanshi Sharma


  • Parina

    Parina Parmar is a full-time dog mom with a knack for content, editing & advertising. She has years of experience in the communication industry, and her dedication to maintaining the integrity of the author's voice while ensuring clarity and coherence in the text sets her apart in her field. She is dedicated to immersing her love for culture, music, and the advertising industry in her works.


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