Development Projects
Side projects, newest first. None of these are for sale — the things you can buy are on the
products page. Published work links to its source; unpublished work is listed
by name with a badge and nothing to click.
If an unreleased project interests you, the thumbs-up is the signal we go by when deciding what to
finish and open.
Applications and tooling
Control and telemetry for e-bike motor controllers, running locally against the bike rather than through a vendor cloud. Built on the OpenBikeControl protocol work, kept private because it ships no binaries and carries a non-commercial licence upstream.
A native SwiftUI iOS app over Coinbase's cb‑mpc library: two-party ECDSA, threshold signing, HD key derivation, key transfer by QR code, and iCloud backup. The cryptography is multi-party computation, so a signing key is never assembled in one place — not even on the phone.
The app repository is private. The protocol walkthrough that came out of building it is public, and it is the more useful half if you are trying to understand MPC signing.
cb-mpc-visual-guide.atsignhandle.workers.dev
Token-efficient communication patterns for Claude Code. A small set of prompts and rules that cut an assistant's output down to the part that carries information, with intensity levels so you can pick how far it goes.
Semantic code search. Indexes a repository into vector embeddings so you can search for what code does rather than for a string it happens to contain — useful in a codebase where the thing you are looking for was named something you would never guess.
Text to speech running entirely on the phone, using the Kokoro 82M model with MLX and Metal GPU inference. No network call, no per-character billing, and nothing you type leaves the device.
On-device LLM chat for iOS built on PrismML 1-bit Bonsai models with Metal GPU acceleration. The point of a 1-bit model is that it fits and runs on a phone at usable speed, so the conversation never has to reach a server.
A privacy-first voice recorder for iPhone and Apple Watch. Transcription runs on the device, with AI summaries, WAV / MP3 / FLAC output, and semantic search across everything you have recorded. Built for iOS 26 and watchOS 26 in Swift 6.
A fork of Blink Mobile Shell, the Mosh-based terminal for iOS. Listed for completeness because the repository is public under our account, but the application is other people's work and the fork exists only to carry local changes. Credit and upstream belong to the Blink authors.
Search 3,860 icons by name or by meaning. Combines SQLite full-text search with semantic search, so “something for deleting a record” finds the trash can even though nothing is called that. A neo-brutalist PWA running on Cloudflare Workers.
fontawesome-explorer.atsignhandle.workers.dev
A local reverse proxy that sits in front of the Anthropic API: rotates between accounts, switches automatically when one hits a limit, logs every request to SQLite, and pushes a notification when something needs attention. A dashboard on top charts token spend, request volume, and which model handled what.
It runs on one machine on a private network and is not published — it is scaffolding for our own work rather than a product, and it holds credentials by design.
Search SEC EDGAR for a company and cross-reference it against the HHS Office of Inspector General exclusion list in the same query. Two public datasets that are individually searchable and, until you join them, awkward to check together.
cik-oig.vercel.app
Search federal court records from the terminal via the CourtListener API. Works out what you meant from a plain-English query rather than making you assemble the flags yourself.
A clipboard security monitor for macOS. Keeps an encrypted history, wipes entries automatically on a timer, and lives in the menu bar. Written because the clipboard is where passwords and keys spend more time than anyone intends.
A JavaScript SDK for managing Copilot.money transactions, categories, tags, and recurring rules programmatically — bulk recategorisation and cleanup that the app itself expects you to do one row at a time.
Signal processing and search
A fixed-point MPEG‑1 Layer III encoder for embedded systems — CBR, VBR, and ABR, quality presets, ID3 tags, and no floating-point unit required. Originally written for ARM7 portable media players between 1998 and 2002, cleaned up and published.
The decoder half: a fixed-point MP3 decoder originally tuned for ARM, MIPS, and SH3 around 1997, updated to build and run on Linux and macOS. Real-time decoding in a very small footprint, with a test suite and audio-quality analysis tooling.
Semantic document search over PDFs: Mistral OCR to get the text out, Inception embeddings to index it, then search by meaning instead of keyword. Ships as Docker with optional GPU support, plus CLI tools for indexing and retrieval.
Measures Transformers.js under ONNX against Python sentence-transformers on legal text, because the received wisdom that you must run embeddings in Python deserved a number attached to it. Includes Triple2Vec knowledge-graph tests, automatic ONNX conversion, and ARM64 and x86 runs.
On-chain
An ERC‑721 that stores its own compressed SVG and its own MP3 on chain, so the joke survives without a server, an IPFS pin, or anyone paying a hosting bill. Comes with a hot-reloading contract development environment, which was most of the actual work.
Generative tile art computed on chain: the SVG is produced by the contract, not fetched from anywhere, with mint proceeds streaming to a Juicebox v2 treasury. Three repositories — the contracts, the minter and gallery front end, and the earlier fully-on-chain port of the original Tiles.art project.
Contracts Minter and gallery tiles-onchain — private
Live demos and dashboards
Small things that exist as a running page rather than as a repository. Some are experiments, some are internal instruments we left switched on.
A browser toy, and an excuse to find out how many independently animated things a page can carry before the frame rate gives up.
millions-of-cats.atsignhandle.xyz
Monitoring for a small fleet of GPU machines — utilisation, memory, thermals, and which model is loaded where — so inference work can be routed to whichever node is actually free.
gpu.atsignhandle.xyz
A market dashboard built to try out a charting approach, kept because it turned out to be the one we actually look at.
stocks.atsignhandle.xyz
Public crime-report data rendered as something you can actually read — the records are already published, but not in a shape that answers a question.
postcrime.atsignhandle.xyz
A working gallery of the UI components used across these projects — the reference we build against, published so a client can see the vocabulary before we start.
interface-components.tankbottoms.workers.dev
Charge history, range over time, and trip logging for a vehicle, pulled from the Tesla API and charted. It sits behind an access gate because the data is one person's movements, so there is nothing public to link to.
Something here worth building on? Bespoke work is on the services page, and rooot [@] atsignhandle [dot] xyz reaches a person.