Show HN: I wrote an email app that accepts only one sender per inbox https://ift.tt/m1nLdrz

Show HN: I wrote an email app that accepts only one sender per inbox Infinite inboxes, including prefixes where you don't have to create inboxes before you use them -- they self create when you add a suffix. Three types of inboxes: - One sender. Locks to the first domain to send email (except gmail, outlook, etc where it locks to an email account for obivous reasons. It bounces everyone else. - Temporary. Lasts for a while (24h, 7days, etc) then bounces. Received messages stay or go as per your choice. - Prefix. The most powerful. Declare a prefix like "service" and then invent any suffix, like "service-netflix" or "service$bank" and it creates a new one-sender inbox locked to whoever wrote first. Bring you own domain. Bring your own AI (MCP server ready). Forwarding. Please help me test it. https://clova.email/ October 15, 2026 at 12:00AM

Show HN: Mixdog – stretch your Claude/ChatGPT subscription with 63% fewer tokens https://ift.tt/wT9IVog

Show HN: Mixdog – stretch your Claude/ChatGPT subscription with 63% fewer tokens https://ift.tt/oDdgZUl October 14, 2026 at 11:33PM

Show HN: XY Music Notation https://ift.tt/Tgh6KID

Show HN: XY Music Notation I've been playing around with a new kind of isomorphic music keyboard that uses a base-12 notation, and wanted some sheet music to learn some new music for it. The idea is to represent each note in 12-TET as a number, so N ∈ (0,1,2,3,4,5,6,7,8,9,X,Y). I used codex to build a music score rendering backend based on MuseScore with custom note heads that display the pitch class of each note. I've found it pretty helpful for learning how to play my own instrument, so wanted to share in case anyone else was interested. https://music.xy.dev/ October 14, 2026 at 12:43AM

Show HN: How Random Are You? https://ift.tt/vkjwpBV

Show HN: How Random Are You? https://ift.tt/qt8oN0c October 13, 2026 at 11:57PM

Show HN: Knitting – A shared-memory concurrency runtime for Node.js,Bun,and Deno https://ift.tt/NGf7A3U

Show HN: Knitting – A shared-memory concurrency runtime for Node.js,Bun,and Deno https://ift.tt/CDZxSBN October 13, 2026 at 10:19PM

Show HN: Closed Form – OpenAI's 372 math results, explained in plain English https://ift.tt/Xy7P9iw

Show HN: Closed Form – OpenAI's 372 math results, explained in plain English https://ift.tt/c7kH5Pl October 12, 2026 at 07:30PM

Show HN: IHMT – Infinite Hierarchical Memory Tree for AI Agents https://ift.tt/envUJcb

Show HN: IHMT – Infinite Hierarchical Memory Tree for AI Agents https://ift.tt/6zsNWKb October 12, 2026 at 11:34PM

Show HN: THX-01 – Open-source decision model, free API, 60M+ tokens processed https://ift.tt/h3yQJVG

Show HN: THX-01 – Open-source decision model, free API, 60M+ tokens processed https://twitter.com/reversedoofz/status/2109228322752471304 October 12, 2026 at 04:31AM

Show HN: Kindlefall a 3D ARPG in the browser, built with Three.js https://ift.tt/FcBpSfL

Show HN: Kindlefall a 3D ARPG in the browser, built with Three.js https://ift.tt/b58KWYc October 12, 2026 at 01:38AM

Show HN: HarmoNova: A modern, customizable Hacker News reader for Chrome https://ift.tt/h7nuevV

Show HN: HarmoNova: A modern, customizable Hacker News reader for Chrome https://ift.tt/8DMPl0d October 12, 2026 at 01:42AM

Show HN: OpenClear – Self-hosted check and ACH fraud screening for small banks https://ift.tt/hbrfiIN

Show HN: OpenClear – Self-hosted check and ACH fraud screening for small banks https://ift.tt/uDb5VYF October 11, 2026 at 11:14PM

Show HN: Throw Alice and Bob into Sagittarius A* https://ift.tt/8gCGPxr

Show HN: Throw Alice and Bob into Sagittarius A* Black Hole Lab is an open source physics simulation of a rotating black hole and two observers, Alice and Bob. You can launch Alice and Bob on paths around or into the black hole and watch events play out. The simulation lets you see a slice of the physics with one or two dimensions of space plus one of time. As a fun extra, Alice and Bob each have a beacon that can transmit a radio wave in all directions. The simulation calculates and shows the wavefront of these signals, accounting for the warping of space and time by the black hole. The simulation also records whenever Alice and Bob receive each other's transmission. The simulation takes pains to respect Einstein's equations of general relativity. To the precision of the numerical integration, the effects shown in Black Hole Lab are really what the math of general relativity says will happen. Black Hole Lab specifically uses the Kerr metric, which is an exact solution to Einstein's equations of general relativity for a rotating mass. That said, physicists agree that general relativity cannot be the final word on black hole physics. Nobody can say what would really happen to Alice and Bob. My original goal for black hole lab was to try to understand the strange time compression effects at the inner horizon, which physicists call infinite blueshift. IMHO, Black Hole Lab succeeds in showing this effect in an understandable way. I added a specific discussion of infinite blueshift in the readme. https://ift.tt/L1VdtNm October 11, 2026 at 04:28AM

Show HN: A functioning Celery Man computer https://ift.tt/a0Jls46

Show HN: A functioning Celery Man computer Hi HN! It dawned on me that the latest AI models (Minimax H3 Max / Audio, GPT-6 Luna) can finally recreate the computer from the classic Tim & Eric Celery Man sketch. I spent a few days creating it: it has 100% parity with the original script, plus anything you ask for (doggy woof woof man or potato boy). Happy to answer any questions about the pipeline! https://celeryman.fun/ October 11, 2026 at 01:08AM