AMX — the open take-off exchange format
Take-off has never had a common language. Afrimo Métré eXchange (AMX) is an open, documented JSON format to describe and exchange a take-off between tools — your data stays portable, with no lock-in.
What is AMX?
A versioned JSON document that describes a take-off neutrally: line items, their reference code (CCTB), the normalised unit, quantity, unit price, VAT rate and measurement rule. It exposes no margin data (cost, materials, labour) — only the shareable take-off.
The common vocabulary (per line item)
- code
- — normalised reference within its référentiel, if available
- referentiel
- — which référentiel the code belongs to: CCTB, BBW, CRTIB (Luxembourg) — a code alone is ambiguous
- designation
- — line-item label
- unite
- — normalised unit (M, M2, M3, KG, PCE…)
- quantite
- — measured quantity
- prixUnitaire
- — reference unit price (excl. VAT)
- tauxTVA
- — line-item VAT rate
- regleMesurage
- — the measurement rule — the key to the common language
Example (AMX v1)
{
"$schema": "https://www.afrimo.be/schema/amx/v1.json",
"format": "afrimo-metre-exchange",
"version": 1,
"devise": "EUR",
"projet": { "nom": "Rénovation Villa", "type": "RENOVATION", "surface": 120 },
"postes": [
{
"ordre": 1,
"code": "21.31.1a",
"referentiel": "CCTB",
"designation": "Gros œuvre — béton armé",
"unite": "M3",
"quantite": 10,
"prixUnitaire": 125.50,
"montant": 1255.00,
"tauxTVA": 6,
"regleMesurage": "Mesuré net en place"
}
],
"totaux": { "montantHT": 1255.00, "nbPostes": 1 }
}Why an open format
Zero lock-in
Your take-off is yours. AMX export is available on every plan — you leave whenever you want, with your data.
Interoperable
A neutral language between tools (spreadsheets, ERPs, and in time the BIM worlds). Anyone can read and produce AMX.
A living standard
The standard emerges from usage, not decree. Every priced take-off also feeds the Afrimo Index, the collective, anonymous price reference.
Network & conformance
Any product that reads or writes AMX joins the network. Conformance is checked via API, and a badge attests it — embeddable on your site.
<img src="https://www.afrimo.be/api/v1/public/amx/badge.svg" alt="AMX v1">