frontpage.
newsnewestaskshowjobs

Made with ♥ by @iamnishanth

Open Source @Github

fp.

Open in hackernews

Show HN: Kalendis – Scheduling API (keep your UI, we handle timezones/DST)

https://kalendis.dev
5•dcabal25mh•4h ago
Kalendis is an API-first scheduling backend. You keep your UI; we handle the gnarly parts (recurrence, time zones, DST, conflict-safe bookings).

What it does: • MCP tool: generates typed clients and API route handlers (Next.js/Express/Fastify/Nest) so you can scaffold calls straight from your IDE/agent tooling. • Availability engine: recurring rules + one-off exceptions/blackouts, returned in a clean, queryable shape. • Bookings: conflict-safe endpoints for creating/updating/canceling slots.

Why we built it: We kept rebuilding the same "hard parts" of scheduling: time zones/DST edge cases, recurring availability, conflict-aware booking, etc. We wanted a boring, reliable backend so we could ship product features without adopting a hosted scheduling UI.

How it's helped: We stopped re-implementing DST/recurrence math and shipped booking flows faster. One small team (just 2 developers) built a robust booking platform for their business using Kalendis—they kept full control of their UX without spending lots of cycles on scheduling infrastructure. The MCP generator cut the glue code: drop in a typed client or route, call the API, move on.

Some tech details: • REST API with ISO-8601 timestamps and IANA time zones • Recurring availability + one-off exceptions (designed to compose cleanly) • Focused scope: users, availability, exceptions, bookings (not a monolithic suite)

The MCP server exposes tools like generate-frontend-client, generate-backend-client, generate-api-routes, and list-endpoints. Add to your MCP settings:

  {
   "mcpServers": {
    "kalendis": {
     "command": "npx",
     "args": ["-y", "@kalendis/mcp"]
    }
   }
  }

How to try it: Create a free account → get an API key. (https://kalendis.dev). Then hit an endpoint:

  curl -H "x-api-key: $KALENDIS_API_KEY" \
 "https://api.kalendis.dev/v1/availability/getAvailability?userId=<user-id>&start=2025-10-07T00:00:00Z&end=2025-10-14T00:00:00Z&includeExceptions=true"
Happy to answer questions and post example snippets in the thread. Thanks for taking a look!

Show HN: I built a synth for my daughter

https://bitsnpieces.dev/posts/a-synth-for-my-daughter/
829•random_moonwalk•5d ago•159 comments

Show HN: PrinceJS – 19,200 req/s Bun framework in 2.8 kB (built by a 13yo)

https://princejs.vercel.app
91•lilprince1218•2h ago•30 comments

Show HN: ESPectre – Motion detection based on Wi-Fi spectre analysis

https://github.com/francescopace/espectre
75•francescopace•7h ago•13 comments

Show HN: Continuous Claude – run Claude Code in a loop

https://github.com/AnandChowdhary/continuous-claude
51•anandchowdhary•2d ago•27 comments

Show HN: Building WebSocket in Apache Iggy with Io_uring and Completion Based IO

https://iggy.apache.org/blogs/2025/11/17/websocket-io-uring/
16•spetz•4h ago•5 comments

Show HN: Bsub.io – zero-setup batch execution for command-line tools

13•wkoszek•6h ago•6 comments

Show HN: Kalendis – Scheduling API (keep your UI, we handle timezones/DST)

https://kalendis.dev
5•dcabal25mh•4h ago•0 comments

Show HN: How are Markov chains so different from tiny LLMs?

4•JPLeRouzic•1h ago•0 comments

Show HN: I have created an alternative for Miro

https://nodeland.io
4•gxara•3h ago•0 comments

Show HN: Octopii, a framework for building distributed applications in Rust

5•janicerk•5h ago•1 comments

Show HN: Hegelion-Dialectic Harness for LLMs (Thesis –> Antithesis –> Synthesis)

https://github.com/Hmbown/Hegelion
2•hunterbown•3h ago•3 comments

Show HN: UltraLocked – iOS file vault using Secure Enclave and PFS

https://github.com/UltraLocked/UltraLocked
3•proletarian•4h ago•2 comments

Show HN: UpBeat – an AI-Enhanced RSS/Atom Reader that only shows you good news

https://upbeat.mitchelltechnologies.co.uk
4•seanmtracey•4h ago•0 comments

Show HN: ToolHop – Fast, simple utilities for every workflow

https://toolhop.app
3•steadyeddy_94•6h ago•0 comments

Show HN: I build a strace clone for macOS

https://github.com/Mic92/strace-macos
2•Mic92•6h ago•0 comments

Show HN: I ditched Grafana for my home server and built this instead

https://github.com/alibahmanyar/simon
6•bahmann•7h ago•0 comments

Show HN: Unflip – a puzzle game about XOR patterns of squares

https://unflipgame.com/
174•bogdanoff_2•6d ago•48 comments

Show HN: Learn Docker in your terminal

https://github.com/furkan/dockerlings
4•furk4n•8h ago•0 comments

Show HN: Internet Object – a lean, schema-first JSON alternative

https://internetobject.org/
2•aamironline•11h ago•2 comments

Show HN: Epub2md – Turn ePub books into Markdown folders for LLM agents

https://github.com/mefengl/epub2md
3•mefengl•13h ago•1 comments

Show HN: Common Sense License (CSL) – civic license for a techno-feudal world

https://github.com/shmaplex/csl
3•shmaplex•14h ago•1 comments

Show HN: Minivac 601 Simulator - a 1961 Relay Computer

https://minivac.greg.technology/
18•gregsadetsky•1d ago•1 comments

Show HN: Encore – Type-safe back end framework that generates infra from code

https://github.com/encoredev/encore
75•andout_•3d ago•47 comments

Show HN: Whirligig.live

https://whirligig.live
10•idiocache•1d ago•10 comments

Show HN: DBOS Java – Postgres-Backed Durable Workflows

https://github.com/dbos-inc/dbos-transact-java
113•KraftyOne•4d ago•57 comments

Show HN: Real-time 4D Julia set navigation via gamepad

https://banditcat.github.io/Atlas/Atlas.html
17•BanditCat•5d ago•0 comments

Show HN: I DON'T want to upload my private files to AI

2•cando_zhou•20h ago•0 comments

Show HN: 13Radar – Real-Time Hedge Fund Portfolio Analytics

https://www.13radar.com/
7•brokerjames•21h ago•3 comments

Show HN: Find Faceless YouTube Channels with AI

2•andybady•21h ago•3 comments

Show HN: CUDA, Shmuda: Fold Proteins on a MacBook

https://latentspacecraft.com/posts/mlx-protein-folding
9•geoffitect•22h ago•2 comments