L XL Classic

Develop Custom Tool Integrations with AI

Your tool isn't supported by GrandTotal? With an AI assistant, you can try to develop your own integration. Choose your AI assistant, give the plugin a name and choose what it should do – import data, export data or an interactive document template for the New menu – and run two scripts – the AI then asks for whatever it needs (e.g. a sample file, or for a web API the address and credentials) and writes the plugin.

Ideas: pre-calculation as a form

Interactive document templates pay off wherever calculation comes before the invoice: enter the key figures, get fully calculated line items. For architects and engineers, HOAI and SIA 102 are ready to use – any other fee schedule follows the same pattern. And far beyond that. Click a card and the wizard picks up the idea:

Print quote

Run size, format, paper, finishing – the template turns them into printing and processing line items.

Solar proposal

Panel count, storage, installation – the AI embeds material prices from your supplier catalog and can refresh them via catalog lookup.

Catering

Guest count, menu line, staff and travel – priced per person including surcharges.

Web project

Toggle service modules, maintenance as a percentage of effort, hosting tiers as optional items.

Image licensing

Usage type, medium, duration and region – license line items from an embedded fee table.

Video production

Shooting days, editing, motion graphics – the license scope as selectable options.

Design usage rights

Base fee times usage factors – scope, duration and territory as selection fields.

Musicians & DJs

Fee, equipment, travel – with surcharges for hours past midnight.

Moving

Rooms become volume – floor, carriers, no-parking zone and boxes as line items.

Painting

Square meters of wall and ceiling, surface, number of coats – material and labor fully calculated.

Cleaning services

Area, interval and building type – calculates recurring items for the service quote.

IT maintenance contract

Devices or workstations times service tier – billed monthly or yearly.

Beyond templates: import hours from time tracking, hand invoices over to accounting, read orders from your shop – the wizard covers all three directions.

1/5

Claude Code –

Codex –

How it works

1. Choose AI assistant

Claude Code or Codex

2. Define the plugin

Scripts appear live

3. Run setup script

Creates skeleton + symlink

4. Prompt in AI assistant

Asks what it needs & writes the plugin

5. Test plugin

Try it in GrandTotal

Input: Name + Import/Export

Goal: Working integration