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Products that do what api-diff does

Catch API contract drift before your users do

  1. 1
    API Diff161

    Diff two API versions in seconds and see what has changed

    2022

  2. 2

    API integration testing that remembers what breaks

    Jul 2026 · fetchsandbox.com

  3. 3
    Prelint603

    Prevent product drift in AI-written code

    Jul 2026 · prelint.com

  4. 4DA

    Hey HN! I’ve written a bunch of WebSocket servers over the years to do simple things like state synchronization, WebRTC signaling, and notifying a client when a backend job was run. I realized that if I had a simple way to create a private, temporary, mini-redis that the client could talk to directly, it would save a lot of time. So we created DriftDB. In addition to the open source server that you can run yourself, we also provide https://jamsocket.live where you can use an instance we host on Cloudflare’s edge (~13ms round trip latency from my home in NY). You may have seen my…

    2023 · driftdb.com

  5. 5IR

    Sharing an internal tool that accelerated my development work 10-fold, especially with API debugging. Thought fellow developers here might find it useful. As a developer, I often have trouble reproducing errors at the client end. https://intercept.rest lets me debug and monitor API requests and responses. It is similar to the Network tab in Chrome Developer Tools but works for any API: mobile apps, webhooks, frontend etc. After I shared it with a close circle of friends, they found it incredibly useful and even found new use cases, I never imagined. Been a long time lurker here and…

    2018

  6. 6
    Diffly6

    Catch API changes before they break your app.

    Sep 2025

  7. 7TD

    Hey HN, I'm Marcel from Tusk. We’re launching Tusk Drift, an open source tool that generates a full API test suite by recording and replaying live traffic. How it works: 1. Records traces from live traffic (what gets captured) 2. Replays traces as API tests with mocked responses (how replay works) 3. Detects deviations between actual vs. expected output (what you get) Unlike traditional mocking libraries, which require you to manually emulate how dependencies behave, Tusk Drift automatically records what these dependencies respond with based on actual user behavior and maintains recordings…

    Nov 2025 · github.com

  8. 8

    The last TypeScript release built on JavaScript

    Mar 2026 · typescriptlang.org

  9. 9
    Recost130

    Your API costs fully visible.

    Apr 2026 · recost.dev

  10. 10DT

    Hi HN - Peter from DBOS here with my co-founder Qian (qianl_cs) Today we want to share our TypeScript library for lightweight durable execution. We’ve been working on it since last year and recently released v2.0 with a ton of new features and major API overhaul. https://github.com/dbos-inc/dbos-transact-ts Durable execution means persisting the execution state of your program while it runs, so if it is ever interrupted or crashes, it automatically resumes from where it left off. Durable execution is useful for a lot of things: - Orchestrating long-running or…

    2025 · github.com

  11. 11

    Runtime behavior diffs for pull requests. Contribute to issacnitin/RealDiff development by creating an account on GitHub.

    11d ago · github.com

  12. 12

    Mock blocked APIs, passthrough ready routes, see live source

    Mar 2026 · mockphine.com

  13. 13IA

    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

  14. 14DA
  15. 15

    Diff two agent runs and see exactly what changed

    Jul 2026 · github.com

  16. 16MV

    I review PRs all day and I've basically stopped reading them. Someone opens a 2000-line PR, I scroll, see it's mostly AI-generated React components, leave a comment, merge. I felt bad about it until I realized everyone on my team does the same thing. The problem is diffs are the wrong format. A PR might change how three buttons behave. Staring at green and red lines to understand that is crazy. The core reason we built this is that we feel that products today are built with assumptions from the past. 100x code with the same review systems means 100x human attention. Human attention cannot…

    Feb 2026 · morphllm.com

  17. 17RR

    I wanted a safer alternative to RegExp for TypeScript that uses a linear-time engine, so I built Regolith. Why: Many CVEs happen because TypeScript libraries are vulnerable to Regular Expression Denial of Service attacks. I learned about this problem while doing undergraduate research and found that languages like Rust have built-in protection but languages like JavaScript, TypeScript, and Python do not. This library attempts to mitigate these vulnerabilities for TypeScript and JavaScript. How: Regolith uses Rust's Regex library under the hood to prevent ReDoS attacks. The Rust Regex library…

    2025 · github.com

  18. 18

    DiffChecker - Smart cURL & Text Compare Tool

    Feb 2026 · diffchecker.virtualisworld.com

  19. 19AS

    Took a stab at building my own string diffing JS package. I built an interactive demo for TypeIt’s website (https://typeitjs.com/build-your-own) a while back. The approach I took to handle user input necessitated a way to calculate the difference between the versions of a user’s text input. I searched around for a package to help me out and found a couple of good ones (like fast-diff), but I either didn’t really like their API or didn’t want to take on a huge new dependency. Instead, I thought I’d give it a shot myself (famous last words). I dove into it having no real formal…

    2022

  20. 20

    Smart REST API Monitoring & Caching. Zero Code Changes.

    Jun 2026 · aproxymade.com

  21. 21TO

    Hi HN! We’re excited to share our new code generator that lets you ship high-quality TypeScript SDKs, that your users will love, from your OpenAPI documents. Our ongoing goal is to help you build one SDK that runs anywhere modern JavaScript runs. This includes new runtimes like Deno and Bun in addition to the ever-popular Node.js. Additionally, the popularity of AI has meant server-sent events and file streaming are also commonplace - we wanted to cover these use cases too. This explosion in new runtimes and ways of interacting with APIs shifts cognitive burden on API developers often having…

    2024 · speakeasyapi.dev

  22. 22

    Block breaking OpenAPI changes before merge

    Jul 2026 · apicontractguard.com

  23. 23IM

    I built this library because I kept rewriting the same fetch wrapper for every project. Each time, I needed the same core features: - Make fetch throw errors to integrate smoothly with libraries like TanStack Query - Add sensible defaults to the Fetch API, like a base URL and authentication headers - Validate responses for type safety when OpenAPI isn’t an option I also wanted the library to feel exactly like using fetch — no new API to learn, and no extra friction for my teammates. While there are other great options out there, I found many were either too rigid or too bulky. Doesn’t it…

    2025 · github.com

  24. 24

    Build complete UIs before your backend exists

    Nov 2025

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