Subcontract ledger workflows for construction and mining

These are Claude Code skills rather than a standalone calculator, so an AI coding agent has to be set up first. They cover progress claims, retention schedules, work in progress and over and under billing under AASB 15, fuel tax credits, the Coal LSL levy, payroll tax on contractors, and plant and equipment costing.

This is not a standalone calculator. It is a set of Claude Code skills, so you need an AI coding agent, such as Claude Code, already set up before any of it does anything. Without one, these skills will not run.

With an agent in place, the skills cover the contracting core: progress claim preparation, retention schedules, work in progress and over-and-under billing under AASB 15, and contract cost tracking. For mining services and earthmoving specifically, they cover fuel tax credit claims, the Coal LSL levy, payroll tax on contractors, and plant and equipment costing.

Each skill encodes the workflow, the steps, the tie-outs, the exceptions to chase, rather than hard-coding rates and thresholds that go stale and differ by state; it sends the agent back to the primary source instead. Two things it deliberately will not do: decide whether a contract is covered by a security of payment Act, or conclude that a worker is a contractor rather than an employee. Both stay with a person.

What this tool does

The contracting core: progress claim preparation, retention schedules, work in progress and over-and-under billing under AASB 15, and contract cost tracking.
Mining services and earthmoving: fuel tax credit claims, the Coal LSL levy, payroll tax on contractors, and plant and equipment costing.
Paying subcontractors: super guarantee under the extended definition, TPAR, and a shared reference skill for the exports these workflows need.

Limits

These skills prepare and check. They do not serve a payment claim, lodge a return, or sign anything. Contract interpretation, eligibility conclusions and professional judgement stay with a person. Nothing here is tax, accounting or legal advice.

Get it

npx skills add ryanduguid/hardhat-ledger

Source on GitHub

Common questions

Do I need Claude Code to use these skills?

Yes. They are agent skills, not a standalone program. Without an AI coding agent such as Claude Code already set up, they will not run.

Will they tell me whether a contract is covered by a security of payment Act?

No. That conclusion, and whether a worker is a contractor or an employee, stay with a person. The skills deliberately refuse both.

Do the skills hard-code rates and thresholds?

No. Each skill encodes the workflow, the tie-outs and the exceptions to chase, and sends the agent back to the primary source for any rate or threshold, because those go stale and differ by state.

Published 24 August 2026. Last reviewed 24 August 2026.

Written independently by Ryan Duguid, a provisional member of Chartered Accountants ANZ, in his own time and on his own equipment.