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Dev tools · alternatives · 2026

24 alternatives to A faster way to prototype your APIs using OpenAPI 3 and Swagger UI

A generator for OpenAPI 3. Contribute to egorsmkv/openapi3-generator development by creating an account on GitHub.

This tool helps developers prototype APIs quickly by leveraging OpenAPI 3 specifications and Swagger UI. It simplifies the process of designing and testing APIs before full implementation. Developers can define their… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. A faster way to prototype your APIs using OpenAPI 3 and Swagger UI launched in 2020; newer entries below may have overtaken it.

  1. 1

    Effortlessly discover API behaviour with a Chrome extension that automatically generates OpenAPI specifications in real time for any app or website.

    2023 · github.com · its alternatives →

  2. 2

    Beautiful API references from Swagger, OpenAPI spec

    2023 · sandbox.scalar.com · its alternatives →

  3. 3

    Generate custom data & API to build apps in less than 30s

    2021 · retool.com · its alternatives →

  4. 4

    Generate and share OpenAPI specs with AI

    2025 · api.dev · its alternatives →

  5. 5

    Develop APIs fast + automatically detect endpoints

    2025 · fastrequest.apidog.com · its alternatives →

  6. 6

    Automagically reverse-engineer REST APIs via capturing traffic - alufers/mitmproxy2swagger

    2022 · github.com · its alternatives →

  7. 7

    Hey HN! We've developed OpenAPI AutoSpec, a tool for automatically generating OpenAPI specifications from localhost network traffic. It’s designed to simplify the creation of API documentation by just using your website or service, especially useful when you're pressed for time. Documenting endpoints one by one sucks. This project originated from us needing it at our past jobs when building 3rd-party integrations. It acts as a local server proxy that listens to your application’s HTTP traffic and automatically translates this into OpenAPI 3.0 specs, documenting endpoints, requests, and…

    2024 · github.com · its alternatives →

  8. 8

    Generate, edit, lint & test your API workflow in one place

    2025 · app.getelva.ai · its alternatives →

  9. 9
    Apidog▲570

    Development teams often struggle with using multiple tools like Postman and Swagger for API design, development, and testing. This fragmented approach leads to outdated API specs and chaotic collaboration. So we built Apidog: a single, unified API platform for team collaboration. It has a beautiful interface that makes it easy to create API spec, generate request data from API spec, validate responses, create mock data, orchestrate test scenarios, and publish API documentation. Apidog = Postman + Swagger + Mock + JMeter.

    2024 · apidog.com · its alternatives →

  10. 10

    Free online tool to test APIs and autogenerate documentation

    2018 · swagger.io · its alternatives →

  11. 11

    We built an open-source tool that scans your codebase and generates OpenAPI docs in minutes. Right now it supports Rails, Go, Python, and NodeJS frameworks, and we will keep adding more. It picks up routes, params, request bodies, and models directly from the code and outputs a clean OpenAPI spec you can drop into your workflow.

    Nov 2025 · github.com · its alternatives →

  12. 12

    Hey HN, we’re building an open specification that lets agents discover and invoke APIs with natural language, built on the OpenAPI standard. agents.json clearly defines the contract between LLMs and API as a standard that's open, observable, and replicable. Here’s a walkthrough of how it works: https://youtu.be/kby2Wdt2Dtk?si=59xGCDy48Zzwr7ND. There’s 2 parts to this: 1. An agents.json file describes how to link API calls together into outcome-based tools for LLMs. This file sits alongside an OpenAPI file. 2. The agents.json SDK loads agents.json files as tools for an LLM that…

    2025 · github.com · its alternatives →

  13. 13

    API design studio for product managers

    2023 · conektto.io · its alternatives →

  14. 14

    Hey, I'm Martyn and I recently joined Zuplo. OpenAPI is a huge part of what we do, but getting a document up to scratch out of the gate, especially if you're not super well versed in the actual specification and what you should use and when. So we built a suite of tools to help with this called Rate My OpenAPI. It will score your OpenAPI document out of 100, as well as giving you individual scores in 4 key areas; completeness, SDK generation, security and documentation. Along with the score, you also get details of what the issues, or errors are, as well as guidance on what they actually…

    2024 · github.com · its alternatives →

  15. 15
    Prototype▲265

    Build your next project in a single prompt

    2025 · github.com · its alternatives →

  16. 16

    Hi, this is Mish and Sebastian. We are working on Step CI - a fully automated API testing platform for developers. Step CI works programming-language independent and for different API paradigms (REST, GraphQL, XML). Our CLI and test runner are available on GitHub (https://github.com/stepci) under the MPLv2 license. Since our last launch, Step CI is now able to generate automated tests for your API based on your OpenAPI (Swagger) spec. This saves you a lot of time as you never have to write and maintain your tests again! We would like to invite you to try our tool and give us…

    2022 · stepci.com · its alternatives →

  17. 17TA

    An OpenAPI alternative to describe REST APIs for type-safe code generation.

    2023 · typeapi.org · its alternatives →

  18. 18

    Port OpenAPI Specs to Postman Collections, inject test suite and run via Newman 👨🏽‍🚀 - apideck-libraries/portman

    2021 · github.com · its alternatives →

  19. 19

    Progressive Web App for generating mocked data from an OpenAPI specification - Fredx87/openapi-mock-generator

    2020 · github.com · its alternatives →

  20. 20MG

    Hey HN, Sagiv from liblab is here. We've been deep in the world of API tooling for years at liblab, primarily focusing on generating SDKs and documentation from OpenAPI specs. Recently, we kept running into a recurring frustration: connecting AI tools to existing APIs is way more complex than it should be. You start with a simple goal – let an LLM talk to your API – and suddenly you're neck-deep in spinning up infrastructure, wrestling with authentication, and writing a ton of custom glue code just to translate natural language into structured API calls. Then you have to maintain it all. To…

    2025 · mcp.liblab.com · its alternatives →

  21. 21

    OpenAPI linting, diffing and testing. Optic helps prevent breaking changes, publish accurate documentation and improve the design of your APIs. - optic/docs/generate-openapi.md at main · opticdev/optic

    2023 · github.com · its alternatives →

  22. 22

    Hey there HN! I just wrapped up an all-day documentation spree for Instant API, a JavaScript framework for easily building web APIs that implements type safety at the HTTP interface. It uses a function-as-a-service approach combined with a slightly modified JSDoc spec to automatically enforce parameter and schema validation before HTTP requests make it through to your code. You just write comments above your endpoint functions and voila, enforced type safety contracts between your API endpoints and your developers. OpenAPI specifications are generated automatically as a byproduct of simply…

    2023 · github.com · its alternatives →

  23. 23

    I’ve been working on an open-source CLI tool called Dochia for a while now. The reason for building it: in microservices architectures, testing is repetitive: every service exposes APIs, and much of the testing process will share a similar set of test cases: negative inputs, boundary cases, encoding quirks, invisible characters. I wanted a tool that could automate this shared layer of testing instead of doing it manually across dozens of services. So what Dochia does: reads your OpenAPI spec; generates thousands of smart, edge-case payloads automatically and produces detailed reports with…

    2025 · github.com · its alternatives →

  24. 24

    Hi Hacker News! My name is Sagar, I’m working on a startup called Speakeasy - we’re making all APIs self-service. The platform is currently in beta, but we’re independently launching this tool which you can use to generate language-idiomatic, statically-typed TS SDKs from any public OpenAPI schemas. We hope to continue iterating on this to give devs a way to easily generate high fidelity client SDKs for all the major languages. Inspiration for this product is from past experiences struggling with OpenAPI. I was originally optimistic about using the OpenAPI tools to build out our offering,…

    2022 · easysdk.xyz · its alternatives →

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Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →