futhr:lab — selected work and research

Connected products still repeat the work of describing devices, discovering them, and binding incompatible protocols. WoTEx develops focused Elixir libraries for W3C Thing Descriptions, interactions, bindings, and discovery across cloud and edge runtimes. Each library follows OTP conventions and stays independently useful: the host application owns its supervision tree, storage, and protocol clients.

Conformance tests tie the shared contracts to published specifications. The aim is reusable infrastructure for Elixir and Nerves teams building connected systems without adopting a proprietary platform.

One standard for Things, and a runtime built to keep them running.

A pure decision engine for products that need booking logic without adopting a booking platform. Availability, time zones, daylight-saving boundaries, capacity, resource assignment, validation, and lifecycle decisions remain deterministic and replayable. ExBooking owns no processes, providers, persistence, or hidden clock, leaving the host in control of customer data, payments, notifications, and experience. The library turns the hardest scheduling rules into a small, testable core that can support many vertical products without forcing them into one operating model.

The rules of scheduling, without the platform.

A notification compiler that moves template risk out of delivery time. Restricted MJML and Liquid become immutable, typed artifacts before reaching production, and runtime nodes render them in pure BEAM code without Node.js or an editor in the delivery path. Publication remains an explicit application decision. Syntax errors, unsafe behavior, and incompatible changes surface during authoring and review, while the artifact contract keeps every delivered message inspectable, versioned, and reproducible.

Compiled before delivery, never trusted at it.

Short strings of symbols are hard to remember. ExkPasswd builds passphrases from independently chosen words, with a public wordlist and strict configuration that rejects invalid or impossible rules before generation. Erlang's crypto module is its only runtime dependency.

Applications can choose from seven presets, load UTF-8 dictionaries, and compose transforms for case, substitution, Pinyin, or Romaji. A supervised registry exposes named presets at runtime; batch generation preserves unbiased selection while reducing calls to the random source. Livebook notebooks cover the basics and multilingual dictionaries.

Words you can remember, rules you can read.

A Solidus shipping calculator for merchants whose delivery economics fit explicit weight rules. Exact-decimal rates cover bands, parcel overflow, handling, free-shipping thresholds, and item constraints without a carrier account or network request. Invalid configuration and missing weights fail visibly instead of generating a plausible but wrong checkout price. The merchant owns a fast, testable pricing model that remains understandable as rates change.

Priced locally, exactly, every time.

A shipping operations layer connecting Solidus checkout, delivery options, service points, booking, labels, cancellation, and tracking to nShift. Every shipment mutation is recorded before dispatch, preserving intent when a provider succeeds behind a failed connection. Ambiguous outcomes enter reconciliation instead of blind retry, and operators retain a clear history of each attempt. Solidus remains the system of record for orders and fulfillment. The extension makes failure recovery part of the shipping model rather than an emergency process after money and parcels are already moving.

Intent recorded before the parcel moves.

Digital art often arrives as a screen or cloud service rather than an object that behaves like framed artwork. Frameshift studies three still-image media—color e-paper, matte LCD, and low-resolution RGB matrix—under one capability-driven protocol. A local host prepares display-specific files and lets each frame retain its last verified image.

The research separates frame hardware from rendering and control, so power, mounting, and protocol choices can be tested independently of any one vendor.

Digital art presented as an object, not another screen to manage.

A headless billing engine for Elixir products that cannot afford drift between what the application believes and what the ledger says. External billing APIs push core commercial truth across a network boundary and leave teams with duplicate models and permanent reconciliation work. Rivure keeps subscriptions, usage, invoices, wallets, payments, and webhooks inside the host application's own data and transaction model, with provider effects handled as recoverable operations.

Unit economics as an architectural constraint: the margin is recorded in the same transaction as the feature that earned it, and every ambiguous provider outcome has a state instead of a support ticket. The engine is designed as open infrastructure; Rivure Cloud is the planned commercial platform for teams that want the same model with managed operations, administration, and regional deployment.

Billing that cannot drift from the product it bills.

Conventional marketplaces centralize inventory and buyer relationships even when goods and sellers are local. Reloved plans autonomous second-hand shops whose operators keep control of their catalogs and sales. The nonprofit Reloved Commons is designed to make eligible public listings discoverable across those shops without becoming the seller or owning transactions.

The first researched profile serves households; later profiles may support reuse organizations and professional shops under their own legal and commercial responsibilities. Shared identity and open infrastructure can make goods easier to find while keeping authority with the people operating each shop.

Owned by the shop, found through the Commons.

A proxy-authorization and coalition platform for Swedish shareholders. Retail ownership is large in aggregate and powerless in practice: proxies are collected by hand, self-declared support is easy to dismiss, and the ten-percent threshold for calling an extraordinary general meeting under the Companies Act is rarely reached because nobody can prove who stands behind it. ÄGR makes every signed proxy, reminder, and dashboard total belong to one specific general meeting, and reports declared, validated, and meeting-eligible support as three separate figures so a campaign cannot be waved away for mixing claims with representation that holds up in the room.

A verified discussion forum per listed company gives coalitions a moderated place to organize before the vote, with evidence bundles that keep every authorization traceable. The product path runs from forum and voice toward trading and asset services, each step earning the next.

Ten percent is only a threshold when someone can prove it.

Two automation rules can be reasonable in isolation and dangerous in composition. The talk makes them fight inside a simulated AGV warehouse, then stops the same conflict before either rule can run. One rule representation feeds both the Maude verifier and the BEAM runtime, reducing divergence between checked policy and executed behavior.

The gate distinguishes verified safety, discovered conflict, and an unverified result. Its value is a concrete deployment pattern for automation systems whose individual rules become dangerous in combination.

Uncertainty never becomes permission.