Skip to content

Damien Chapus · Antibes, France

HORIZON BUILDER

horizonbuilder.space

Building AI tools that belong to you.

A guild of builders in the age of artificial intelligence. We build the infrastructure — software, embedded AI, ownership of your data — for an environment that is more sovereign, more human and more transparent. The models run on your own machine: they understand speech, read your documents, sort your inbox — and keep nothing.

The work is shared: fourteen pieces of software, and a club that measures what platforms take down and runs a watch on the world for its members. Joining is free, and nothing is sold there.

Create my profile Request my membership card

The fourteen products · The Radar, OSIRIS and Insight France · The club and its instruments

What Horizon Builder is

A guild of builders,
in the age of artificial intelligence

The cathedral builders passed on a craft, a set of rules and one demand: the work had to serve those who came after. Horizon Builder takes that spirit to where everything is decided today — AI, data, and the tools that shape our lives. We build infrastructure that belongs to the people who use it.

Against what? Against the dominant model. Most platforms create value in order to place themselves between people and take their cut. You can build the opposite: software that does one thing, does it well, and gets out of the way.

  1. Build the infrastructure Software, online tools, robotics, embedded AI. Not services rented from whoever hosts them, but work that stands on its own on the machine of the person using it.
  2. Own the data Your documents, your meetings, your accounts, your files. Our models run on your machine: the data is not monetised elsewhere, because it never leaves.
  3. Make information transparent What platforms take down, what the state spends, what moves in the world. Measured, sourced, exportable — and open to challenge by anyone willing to redo the maths.
  4. Stand together Real mutual support: tools go to members first, and what members actually use decides what gets built next.
The work

Fourteen pieces of software, five in production. Each one is a proof: local, no commission, no middleman taking a cut.

The method

Vibe coding throughout. AI writes, tests and documents; the human decides what deserves to exist and what gets thrown away. That is how one person keeps fourteen products running.

The opposite of secrecy

The old lodges kept theirs. Here it is the reverse: figures are exportable, membership cards can be verified by a third party, and the code does what it says.

The limit

No fundraising, no data resale. What cannot be funded by the people who use it does not get built.

Horizon Builder is not affiliated with any order or obedience: the lineage claimed here is that of the craft — to build, to pass on, and to keep your word about what you ship.

How it is organised

Three circles, three levels of access

Not everything built here is meant to be public, or to be sold. Each tool belongs to one of three degrees — and the community is the one that moves fastest.

First degree · public

Software open to everyone

The products that are sold or freely available: VirtualHost.ai, Hivernago, Séjours Privés, SphereFlow. You reach them without asking anyone, and you pay if you use them. They fund everything else.

See the software →
Second degree · the community

Privileged access and testing ground

Tools I build for myself first, then open free and ahead of everyone else to those who joined: VIGIE for finances, Cockpit for email, and the ones that follow.

It is also the human-scale testing ground: every tool is proven by a few dozen real people before it is industrialised or opened more widely. Nothing ships at scale without having served here first.

How to join →
Third degree · the workshop

The control hub

The dashboard that centralises every project, its back-office and its data. It is not public and will not be: it's the workshop, not the shop window. Some of its modules will end up open to the community.

Restricted access

The software

Fourteen products, one rule

Published by Damien Chapus EI, a sole trader registered for software development since May 2023.

On sale

VirtualHost.ai

Minutes for French works council meetings. Embedded transcription and speaker identification, compliant minutes generated — without a single recording leaving the machine. Sold per mandate.

virtualhost.ai →
Launching

Hivernago

Winter storage for boats, motorhomes and leisure vehicles along the French Riviera. Land eligibility checks, direct introductions.

hivernago.fr →
Launching

Séjours Privés

Book the family house, or a friend's, with the convenience of a platform and none of the commercial logic. Synced calendars, request handling, zero commission.

sejoursprives.com →
Online

SphereFlow

Automated B2B prospecting. Builds the target list from French public company records, scores it with a rating that explains itself criterion by criterion, then checks every address against the server that would receive it before anything is sent. Messages leave from the salesperson's own mailbox, never ours — and that mailbox is never read.

sphereflow.eu →
In-house, running

Mixprism

DJ set analysis: track identification, audio fingerprinting, crate preparation. Born from a producer's need, the tool has closed to the public: it now runs in-house.

mixprism.eu →
In-house, running

MixClip Editor

Automatic editing for multi-camera DJ sets. Drop the rushes and the audio master: every angle syncs itself to the mix, cuts land on the musical phrase instead of at random, thumbnail and preview are produced, and a quality check runs before anything goes out. Golden rule: the picture never cuts the music.

In-house, running

MixStream

Broadcasting one live set to several platforms at once from a single feed relayed by our own server — instead of one upload per destination. A cockpit drives the studio, opens and closes the stream, and publishes the tracklist at the end.

On sale

Reverse Reverb Swell

Audio plugin, VST3 and standalone (Windows). Load a sound and out comes the reverse-reverb swell that rises into the attack — one click, where it used to mean flipping the file by hand. Selectable working area, presets, tempo sync, and the result drags straight into your DAW.

See the plugin →
In development

Harmonic Bender

A writing plugin: slide a single note of a chord up or down, degree by degree, never leaving the scale — driven by a plain automation curve. The other notes stay put. Built for piano-roll writing, where existing tools aim at the stage keyboard.

The laboratory

UpMyChain

The services marketplace where contribution, not starting capital, grants access. The project's first testing ground — and where all the rest came from.

Prototype

PHOS

Censorship-proof broadcasting: a message travels from a screen to a camera with no network and no pairing, spreads from relay to relay, and stays verifiable back to its author through a signature that rides along with it.

In development →
Free and public

The Radar

Measures what platforms remove in France, from their own filings to the European register. Raw figures, published method, stated limits — so anyone can redo the calculation and prove us wrong.

See the figures → Join the club, free →
Members only

OSIRIS

A live watch on the world, on a single map: flights and ships, earthquakes, conflict zones and translated dispatches, international sanctions, markets and public cameras. Open sources only, cited and shown as they are — no commentary, no ranking. Free for club members, on approval.

What OSIRIS shows → Join the club, free →
Members only

HORUS

The Earth seen by laser, in black and white, stripped of what covers it: forests and buildings removed, only the ground remains. Terraces, ditches, hollow ways and enclosures that aerial photography hides under the trees stand out in relief. The tool for archaeological survey and for reading the history of a landscape. Free for club members, on approval.

How HORUS sees under the forest → Join the club, free →
Members only

The club's tools

A dossier gathering everything public data says about a company or an address. French law searchable word by word. Five measuring instruments: whose network carries public services, who lobbies the state, where public money goes, what the network blocks. An explorer to cross-reference it all, and a detector of what gets quietly rewritten. Free for members, on approval.

What the tools open → Join the club, free →
Public · detail reserved for members

Insight France

What the French state collects and what it spends, the country's demographics, and the real life of its companies — charted from INSEE, DGFiP and BODACC data. Every figure carries its source and its date. The headline numbers are public; the breakdown by ministry and by département is reserved for club members. French-language page.

Open Insight France → Join the club, free →

The club · free membership

See it at the source, and carry weight

Horizon Builder does not only write software. It also runs a club, and that club has a job: to put instruments of measurement and watch into its members' hands — instruments you will not find elsewhere — along with the numbers it takes to use them. Free, no payment, no password.

Public and free

The Radar

What platforms take down in France — measured.

Nine speech platforms declare every content removal to the European registry. The Radar downloads those declarations, counts them and publishes the result: raw figures, public method, stated limits. It updates itself every night.

We name no offence, and we do not claim the removed content was lawful — the platforms do not say so. We record a measured gap, we publish how it was calculated, and we hand you what you need to prove us wrong.

See the figures →
Members only · on approval

OSIRIS

What is happening in the world, right now, on a single screen.

OSIRIS answers one plain question: what is happening, where, and now? It gathers on one map what you would otherwise chase across ten different sites — and it shows it raw.

  • Sky and sea. Flights and vessels tracked live. An airspace closing, a strait ships suddenly start avoiding: you read it on the map before it becomes a headline.
  • The ground. Earthquakes as they are recorded, magnitude and depth, wherever they strike.
  • Conflicts. Active zones and open-source dispatches, translated.
  • Sanctions and markets. International decisions and prices, to place an event in its economic context.
  • Public cameras. Video feeds already open to everyone, gathered in one place — that layer needs club level.

It is not a news feed. No commentary, no ranking, no recommendation: public sources shown as they are, and the reading is yours to do. It is the exact counterpart of the Radar — where platforms sort and remove, OSIRIS simply shows.

Get the card, then request access →
Members only · on approval

HORUS

Bare ground, without the forest that hides it. Anywhere on Earth.

A full-screen map, in black and white, where vegetation and buildings have been removed from the terrain. What is left is the exact shape of the ground — and with it everything the centuries left on it: farming terraces, ditches, hollow ways, enclosures, burial mounds, old field systems. Aerial photography shows the tops of the trees; HORUS shows what lies beneath them.

  • The laser slips between the leaves. That is the whole principle of LIDAR: millions of pulses per second, most bouncing off the canopy, a few threading their way down to the ground. Keep only those last echoes and you rebuild the terrain as if the forest were not there.
  • From orbit, for the whole world. Two NASA lasers — ICESat-2 and GEDI, mounted on the International Space Station — probe the surface of the globe. Some thirty billion of their measurements went into building a worldwide terrain model. No point on Earth is left out.
  • From the aircraft, for the detail. Over France, the IGN LIDAR HD programme goes down to 50 cm: you can make out a bank, a gully, the line of a levelled wall. HORUS switches to that resolution on its own wherever it exists.
  • Turning the light. The archaeologist's move: a structure invisible under one lighting angle leaps out under another. Sun azimuth is a slider.
  • Compare with a swipe. Bare ground on one side, aerial photography or the canopy on the other, split by a handle you drag. That is where you measure what the forest was hiding.

Nothing invented, nothing interpreted. HORUS adds no layer of reading: it displays public measurements — IGN, NASA, OpenStreetMap — and cites them. What you see is the survey, not a hypothesis. Search accepts a city name, an address, or GPS coordinates in decimal degrees as well as degrees-minutes-seconds.

Get the card, then request access →
Members only · on approval

The club's tools

What public data already says, but that nobody assembles.

All of it is built on open, free, cited sources — IGN, INSEE, the French official gazette, the transparency register, RIPE, NASA, OpenStreetMap. None of it is secret. What was missing is someone putting them together and making instruments out of them.

  • The dossier. Type a company name: you get its identity, the public contracts it won and their amounts, and whether it is registered as a lobbyist. Type an address: bare-earth relief, the underground cavities beneath it, polluted sites, and the price of every sale in the neighbourhood.
  • The law, word by word. Full-text search across the 161,000 articles in force of the French codes. It quotes them as published — it does not interpret them, and that is deliberate.
  • Five measurements you will not find elsewhere. Whose network actually carries the state's websites · who lobbies public decision-makers · who receives public money · what the network blocks. Every page carries its source, its date, and says what it does not prove.
  • The explorer. All that data in one place, to sort, cross-reference, query in SQL and export.
  • What changes in silence. Public pages re-read regularly, and the word-for-word diff of what was rewritten. The Radar measures what is taken down; this measures what is rewritten.

A single request opens all of it. OSIRIS and HORUS are requested separately.

Get the card, then request access →
Open to all · detail reserved for members

Insight France

What the state collects, what it spends, what is left.

The French state's revenue and spending month by month, the country's demographics, and the real life of its companies — every incorporation and every liquidation, as published in the official gazette. No opinion, no side: data from INSEE, the DGFiP and the BODACC, each figure carrying its source and its date, and a table of numbers behind every chart. Updated weekly.

  • Freely available: the budget balance, the main revenue and spending blocks, eighteen years of company formations and failures, and the country's natural population balance.
  • Members only: state spending ministry by ministry, insolvency proceedings département by département, the full series, and a CSV export of the data.

These figures are public. They are simply unreadable where the administration publishes them: monthly PDFs, files of five million rows. The work is making them readable — and saying, every time, what the data does not allow anyone to claim. The page itself is in French.

See the figures →
Nothing that is not already public

OSIRIS aggregates open sources only, and cites them. It collects nothing, listens to nothing, follows no one.

On our servers, in Europe

Aggregation and translation run on our own machines in Frankfurt. What you consult goes to no third party.

When in doubt, the original

A suspicious translation is dropped in favour of the source text. A plausible fake is more dangerous than an outage.

Access that can be closed

Entry is named and approved one by one — not out of scarcity, but so that an access can be withdrawn.

What the card also opens

  1. The reason explorerThe full list of wordings platforms send out, filterable. The public table shows only twelve.
  2. Export and historyThe figures as CSV and their series over time — to redo the maths, or to contradict us.
  3. The Insight France detailThe state's accounts mission by mission, beneath the public summary.
  4. Your membership cardNamed and signed. Anyone can verify it with the public key alone, even if this server goes dark.
  5. The software, before anyone elseSecond-degree tools while they are still being built, and your use decides what ships next.

The weight of numbers. A figure published by one person alone gets ignored. Published on behalf of thousands of members, it has to be answered. That is the only thing the club asks of you: to be there.

Request my membership card See the figures

Every membership is subject to approval by the administrator: the club is built member by member, there is no automatic sign-up. Once approved, you receive your card link — that link is your club space, and there is no password to remember. OSIRIS access is requested afterwards, separately.

Joining reveals a political opinion, sensitive data under Article 9 GDPR: the membership is stored encrypted, inside the European Union, for the sole purpose of keeping the member register. Erasable in one click.

What it changes

What a member gets, and a visitor never will

Part of what I build will never be put on sale. These are tools written for my own use, too specific to be commercialised, but that save hours to anyone with the same problem. They exist nowhere else, and they will go no further than the community.

  Visitor Horizon Builder member
The software that is sold At public price At public price
VIGIE, Cockpit and the internal tools No access Included, free
Tools that are never commercialised Do not exist for them Exclusive access, nothing asked in return
New releases At public launch, if there is one First, before any industrialisation
What gets built next Decided for them Decided by their feedback
Tool licence None Named and signed, issued to the member
Getting in touch A contact form A direct reply — I'm the one reading

A licence in each member's name

Every community tool ships with a cryptographically signed, named licence — the same mechanism that protects VirtualHost.ai. It carries the member's name, is not transferable, and stays revocable.

In practice: the licence is verified offline by the tool itself, calling no server at all. It identifies its holder, and the tool displays whose copy it is. This is not a subscription in disguise — it costs nothing and doesn't expire while you're a member.

What it is not: an unbreakable lock. Software running on its user's own machine can always be copied — anyone claiming otherwise is lying to you. What the licence guarantees is that every copy is identified, and that the community stays what it is: people, not copies.

Named

Issued to the member and following them from one tool to the next. One holder — not a household, not a company.

Signed

Ed25519 signature, verifiable offline. A forged licence fails the check.

Offline

No server call, no telemetry, no account to open. Verification happens entirely on your machine.

Revocable

A shared or resold licence can be invalidated at the tool's next update.

All of it with no subscription, no password and no payment. The only thing expected from a member is to say what works for them and what doesn't.

Free for the community

My own tools, opened up

I wrote them for myself and they run on my machine every day. They send nothing anywhere — no account to create, no server to trust. It's the simplest demonstration of the thesis. One exception, the latest arrival: OSIRIS aggregates public sources from around the world, so it runs on our own servers in Frankfurt — and stays free for club members.

Free for members

OSIRIS · new

What is happening in the world, right now, on a single screen. A live map that gathers what you would otherwise chase across ten different sites: flights and ships tracked in real time, earthquakes the moment they are recorded, conflict zones and open-source dispatches, international sanctions, markets, and the public cameras already open to everyone.

What it is for: seeing an airspace close or a strait being avoided before it becomes a headline. It is not a news feed — no commentary, no ranking, no recommendation: public sources shown as they are and cited, and the reading is yours to make.

Live · members only, on approval
What OSIRIS shows, in detail → Join the club and request access →
Free

VIGIE

Household finance control. Imports your bank statements with no API at all: nothing to authorise, no delegated access. Reconciles payslips against incoming transfers, spots dormant subscriptions and silent price rises. Read-only: no money movement is possible.

Public version in preparation
Free

Cockpit

Work inbox triage. Groups threads by subject, prioritises, drafts replies grounded in your own procedures and tone. Runs on the mail client you already have — the mailbox is never copied anywhere.

Public version in preparation
Free

And next

The following tools will come from the same logic: a real need, a lean answer, executed locally. The community sets the order — that's what joining is for.

Have a say →

Join the community

Three steps, and an email address

No account to create, no subscription, no referral. You leave an address, you get the tools. In return, your usage steers what ships next — that's all that is expected of you.

  1. You leave your details below Two required fields. No data passed to third parties, one-click unsubscribe in every message.
  2. You get the tools before anyone else The software, its documentation, and exactly what it does with your data — which is nothing, since it runs on your machine. You are its first real users, ahead of any industrialisation.
  3. You reply if it helps you A bug, an idea, a use case I hadn't thought of. I'm the one reading, and that's what decides the next tool.

No password to remember, no data passed to third parties, one-click unsubscribe. One letter a month at most.

What the community space holds →

Two doors, not to be confused

The Horizon Builder profile The form above. It gets you the community software early, and a membership card. No opinion is recorded, no particular consent is asked for.
The club card A separate step. It opens the Radar explorer, the export, the historical series, and lets you request access to OSIRIS. Joining reveals a political opinion: consent is therefore explicit, and nobody is moved there automatically.
Request my membership card What the club opens

Who builds this

Damien Chapus

Sales by day, developer by night. Seven years in the field as a corporate sales rep taught me what a time-wasting tool really costs — and that's where the obsession with leanness comes from. I write this software alone, starting from problems I ran into myself: hence its range, and its family resemblance.

Electronic music production is the other side of the work. It's not a biographical footnote: it's where Mixprism came from, and where the demands on form come from too — the black, the absence of visual chatter. Software is built like a track: you strip away until only what matters is left.

Full background on LinkedIn → contact@horizonbuilder.space
The field

Seven years of corporate sales on the French Riviera, with companies of every size.

The company

Damien Chapus EI — software development, registered with the Antibes commercial court since May 2023.

The music

Electronic production, label releases, mixing. The origin of Mixprism.