Mocktail – Free, open-source mock API server with a built-in dashboard

In plain words

Mocktail is a free, open-source mock API server distributed as a single 25 MB binary for local or self-hosted use. It includes a built-in dashboard and database, allowing developers to define endpoints, generate realistic test data, customize response headers and status codes, and simulate latency. The tool lets users inspect incoming requests in real time and supports optional AI assistance and coding agent integration through MCP support, with no account or external service required.

written from the facts on this page · September 2026

From the sources

Self-hosted mock API server + dashboard in one ~25 MB binary. Define endpoints, generate realistic data, test errors and latency, and inspect live traffic.

A complete mock server, dashboard, and database in one ~25 MB binary. Mix one up locally in seconds — or self-host it on your own infrastructure. Model the responses your app expects — headers, delays, even the flaky 401 — and let Mocktail keep the data lively. Write and validate JSON right in Mocktail. Keep responses fixed, generate fresh values on every request ( uuid, email, price, name ), or swap real fields for fake data when you need to anonymize a response. Create an endpoint, hit Test right from the dashboard, and watch it land in the live stream — method, status, latency, and the exact response and headers served. Filter by path or status. The whole loop, without leaving the app.…from getmocktail.com

In the maker’s words, at launch

Hi HN, I built the first version of Mocktail years ago. I recently came back to the project, and after a pretty substantial rebuild, v4 is now out. Mocktail is a free and open-source, self-hosted mock API server with a built-in dashboard and database, packaged as a single ~25 MB binary. You can run it locally or on…

• 
  Mockoon – mock REST APIs in seconds2017 · mockoon.com · ▲68

  Mockoon is the easiest and quickest way to run mock REST API servers. No remote deployment, no account required, free, open source and cross-platform.

• MO
  Mockit – Open-source app to create and configure HTTP mocked endpoints2019 · mockit.netlify.com · ▲158
• 
  HTTP Mock – Intercept, debug and mock HTTP(S) with zero setup2019 · httptoolkit.tech · ▲341

  Beautiful, cross-platform & open-source tools for debugging, testing and building with HTTP(S), on Windows, Linux & Mac.

• 
  Mockaroo2015 · mockaroo.com · ▲354

  A realistic data generator to test your app

• 
  Mockoon2017 · mockoon.com · ▲89

  Mock servers in seconds

• MS
  Mocktastic – Simple, Offline mock REST APIs for your entire team2018 · mocktastic.com · ▲43

• 
  /dev/null▲486

  a social network for devs

  Dev tools · 3d ago · dev-null.sh

• 
  Whiteboard (YC W26) – an open-source IDE for thoughtful software design▲423

  open-source IDE for thoughtful software design. Contribute to devdotfast/whiteboard development by creating an account on GitHub.

  Dev tools · 28d ago · github.com

• 
  Reladraw – A diagram language where you decide where to place things▲411

  Contribute to reladraw/reladraw development by creating an account on GitHub.

  Dev tools · 26d ago · github.com

• 
  OpenBot▲362

  Grok Bot alternative: free, local, open-source, multiplayer

  Dev tools · 23d ago · openbot.run

• 
  Talanoa▲346

  Hi HN, I’m a fullstack developer, and honestly, I’ve lost count of how many side projects I’ve worked on over the years. But one idea kept coming back to me: a different kind of email client. It first came to me in 2014: “What if we could handle emails more like conversations?” Every year, I’d revisit this concept in my “Build Notes.” Ten years later, no one had built exactly what I had in mind — so I finally decided to do it myself. That’s how Talanoa was born. I wanted something focused on people, not timelines. I was tired of marking messages as unread just to remember to reply later, or…

  Dev tools · 21d ago · talanoa.email

• 
  CoreSpeed▲332

  One MCP for everything your agents need: apps, memory, tools

  Dev tools · 28d ago · corespeed.io

• TL
  The load-bearing vocabulary of Claude▲710

  Life & fun · Aug 2026 · louisabraham.github.io

• 
  Hey Noah▲656

  A proactive AI executive assistant for founders

  AI · Aug 2026 · heynoah.io

• 
  Clipto MCP▲655

  Hey HN, We recently built Clipto. It’s a tool that lets you search over terabytes of video, audio, and images on your computer, without relying on the cloud. Motivation: we probably all had this similar experience, we know a moment exists in a video or audio, but finding it takes hours scrubbing the timeline. You can send all the media to process in the cloud, but it’s slow, expensive and raises privacy concerns. So we decided to build our own on-device media search engine. How it works (high level): 1. We ingest video, audio, image; normalize formats via ffmpeg; run content analysis to…

  Work · Aug 2026 · clipto.com

• 
  Simple algorithm and color space to generate diverse skin tones▲627

  Hello HN! I found that picking out plausible but diverse skin tones for my digital art and game development projects was kind of difficult, and I got curious about if there was a way to define a color space that made it easy. I've built a color picker and procedural generation algorithm based on the space as well as a bunch of other fun js features and demos throughout the page that use the equations. If you find it interesting, I have lots of explanations of how I built it and what properties the space has. The methodology might be a bit shaky, but hopefully the result is as helpful for…

  Life & fun · Aug 2026 · toneyalexander.github.io

• 
  AdAnt AI▲620

  Claude for viral, high-converting social ads

  AI · Aug 2026 · adant.ai

• 
  Astute▲606

  Automate your B2B brand going viral, with new media creators

  AI · Aug 2026 · company-app.joinastute.com