How to Merge Two Swagger JSON Files? Complete Guide

Quick Answer: To combine Swagger JSON files, merge their API paths, schemas, tags, and other definitions into an individual JSON file, then validate the combined data. For small files, do it manually using a basic text editor or use CLI tools. A dedicated software solution is another option for no-code merging. Before you merge two Swagger JSON files, ensure both use the same OpenAPI specification edition & Swagger to eliminate errors.

This guide will cover different methods to combine multiple Swagger files, from basic to advanced solutions. Each technique has its own process and drawbacks, so you can choose the method that depends on file size, technical expertise, and how often you need to merge them. Now, let’s begin the discussion.

What is a Swagger JSON File? Overview

A Swagger JSON file is a structured, machine-readable document that describes a REST API, including its endpoints, parameters, responses, request bodies, and other important details. Here are some key points about the file:

Generally saved in swagger.json or openapi.json format.
The UI of Swagger is used to create API documentation.
Swagger 2.0 uses the format: “swagger”: “2.0”.
OpenAPI 3.x uses the “openapi” field, such as “3.0.3” or “3.1.0”.
Some main sections are info, paths, definitions, tags (Swagger 2.0), & components (OpenAPI 3.x).

Overall, knowing the structure of Swagger JSON file makes it simple to identify the sections that need to be merged during the process. Understanding how paths, components, tags, or definitions work helps users combine API documentation without affecting the current file structure. Now, let’s look at the reasons behind merging.

Why Need to Merge Two Swagger JSON Files? Key Reasons Explained

When your API documentation is split across multiple Swagger JSON files, combining them brings all endpoints and definitions into one well-organized document. It helps to make the data easier to view, analyse, manage, and validate. Here are some reasons why users need to combine multiple Swagger JSON files into one:

Microservices: Merging two Swagger JSON files from different services, including users, orders, payments, etc into a single document for smooth API management.
Multiple API Editions: Allows users to bring versions together when they need to be published by same developer portal or any other documentation platform.
Support Large Projects: Combine API documentation managed by teams or modules during development.
Accurate API Definitions: Join all endpoints, schemas, parameters, responses, etc while preserving the entire API structure.
Centralized Documentation: Manage all details in one Swagger JSON file, which is useful for developers to manage the API efficiently.

If you merge two Swagger JSON files into one, it helps to bring divided API definitions together and makes documentation easier. Now that we have read the common reasons to combine Swagger files, it is time to proceed with a step-by-step approach on how this process can be carried out.

How to Combine Swagger JSON Files into One? 3 Best Methods

If you are wondering how to merge Swagger JSON files, here are the effective solutions. Using any of these approaches, you can create a single document for easy sharing, viewing, editing, etc. Now, let’s walk through the basic to dedicated solutions:

Manually Merge (Text Editor)
Automated Software (Offline & Recommended)
Python CLI Tools (Code-Based)

Now, let’s understand each method in detail.

#1 How to Merge Two Swagger JSON Files Manually?

For a small number of Swagger JSON files, you can use a basic text editor such as VS Code or Notepad++ to combine the sections manually. This solution does not require any additional software, but it needs to be handled securely to avoid duplicate schemas, paths, and other details. Now, follow the quick steps to combine Swagger files into one:

Open two Swagger JSON files in a text editor.
Now, use paths section in both .json & copy the required API endpoints into one file.
Merge definitions and components, and also check for duplication.
Now, save the combined document as a new Swagger JSON file.
Check the merged file using a suitable OpenAPI validator.

Limitations of Using Manual Text Editor:

It is a time-consuming process for merging multiple Swagger JSON files.
Any duplicate keys, schemas, or paths can cause conflicts.
Manually combining may affect API structure and lead to errors.
Proper and careful validation is needed after completing the task.

#2 Combine Multiple Swagger Files into One – Try Automated Approach

When you need to merge two or more Swagger JSON files quickly, a desktop solution can help reduce the manual editing. Here, SysTools JSON Merge Tool offers a direct and instant way to combine a large number of Swagger JSON files into a well-structured single document in just a few clicks. An offline utility is useful when Swagger files contain large number of schemas, endpoints, and API definitions. Here are the key benefits of using the expert-recommended solution:

Allows users to merge two Swagger JSON files in batch mode.
Works on local system without uploading API data to any external servers.
Review the Swagger JSON data before proceeding with the merging process.
Offer a clean and easy-to-navigate interface without writing scripts.
Provide 24/7 technical support to guide users if they have any queries.

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So, download the Pro solution and explore its features by combining two Swagger JSON files into a single document with ease.

Guide to Merge Two Swagger JSON Files into One Document

Download and run the automated tool on your machine.
Use the Add Files or Folder option to upload Swagger JSON files in bulk.
Select an option to choose Primary File and navigate to Change to set the location.
Now, click the Merge button to finish the merging process.
Lastly, tap View Report and open a combined document.

#3 How to Combine Swagger JSON Files Using Python CLI Tools?

Python is a code-based solution that is convenient for those who are familiar with technical knowledge, like developers or tech-savvy users. You can use programming libraries or custom scripts to read JSON, merge the desired objects, and write output to a new combined file. Here are the working steps:

Install Python and create a script for reading Swagger JSON files.
Browse both files using the built-in json module and combine specific sections.
Now, write the combined data to a new .swagger json file and run the script.
Finally, validate the resulting document.

Limitations of Using Code-Based Approach

Requires installation of Python and programming knowledge.
Custom conflict handling needs additional code.
Incorrect merging can cause errors and can overwrite API definitions.
Scripts need to be modified when the file structure changes.

Which Method Should You Choose to Merge Two Swagger JSON Files?

The right technique depends on number and file size, your coding skills, etc. So, in this section, through a comparison table, we will help you pick the perfect method to combine multiple Swagger JSON files into one.

Comparison Factor	Manual Merging	Offline Automated Tool	Python Script Solution
Merge Multiple Swagger Files	Limited Support	Yes, supports bulk merging	Yes, using additional code
Technical Expertise	Limited	Zero Coding Required	Basic to Advanced Required
Customization	No	Moderate	Highly Available
Preserve File Hierarchy	Less Availability	Yes, maintains structure	Depends on Script Creation
Remove Duplicacy	Manually	Tool-based	Code-Based
Best Suitable	Only for Small Files	Bulk & Regular Combining	Developer & Automation

Bonus Tip: What If You Need Only Specific API Sections?If you are dealing with large Swagger JSON Files and need only certain API data, dividing the file into multiple small parts can make the entire process effortless. It helps to separate data by keeping the important section and then merging the required files into a single Swagger JSON document. Using a robust solution like SysTools JSON Splitter Tool can help both professionals and beginners break Swagger files in seconds.