Australian accountant based in Newcastle, NSW. Engineering computational accounting engines, native Excel dynamic-array LAMBDAs, Model Context Protocol (MCP) servers, and deterministic AI workflows for Australian taxation, payroll, and statutory compliance.

Provisional member of Chartered Accountants ANZ • SAP S/4HANA Certified (FI & CO) • Xero specialist certification (Level 3)

Integrate Australian statutory rules and deterministic computational engines into AI development environments:

# Add Australian Accounting & Tax MCP server to Claude Code
claude mcp add aus-accounting -- uvx --from git+https://github.com/ryanduguid/au-tax-mcp-server aus-accounting-mcp

# Add Public Practice & Tax skills
npx skills add ryanduguid/australian-accounting-skills

# Add Construction & Mining Subcontractor skills
npx skills add ryanduguid/hardhat-ledger

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flowchart LR
    subgraph Data ["1. Data and ledgers"]
        direction TB
        Xero["xero-trial-balance-export<br/><i>Validated Xero TB Export</i>"]
        PQ["accounting-excel-toolkit<br/><i>Power Query (M) & VBA</i>"]
    end

    subgraph Engines ["2. Rules and engines"]
        direction TB
        Ozzit["Ozzit<br/><i>130 Native Excel LAMBDAs</i>"]
        Tally["TheExchequerTally<br/><i>Company Tax & Franking FAB</i>"]
        Sword["SolomonsSword<br/><i>Trust Div 6 & s100A Matrix</i>"]
        ATO["ato-benchmark-compare<br/><i>ATO Benchmark Compare</i>"]
        Super["payday-super-checker<br/><i>Payday Super & SG Charge</i>"]
    end

    subgraph AI ["3. Agent workflows"]
        direction TB
        MCP["au-tax-mcp-server<br/><i>Unified MCP Server</i>"]
        Skills["australian-accounting-skills<br/><i>Public-Practice Skills</i>"]
        SubSkills["hardhat-ledger<br/><i>Construction & Mining Skills</i>"]
        DrD["DrDebits<br/><i>APES 110 & TPB Ethics Gate</i>"]
        Gateway["xero-ai-review-gateway<br/><i>Zero-Network Review Sandbox</i>"]
    end

    Data --> Engines --> AI

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    classDef aiBox fill:#2D184E,stroke:#8A4AC7,stroke-width:1.5px,color:#FFFFFF;

    class Xero,PQ dataBox;
    class Ozzit,Tally,Sword,ATO,Super engineBox;
    class MCP,Skills,SubSkills,DrD,Gateway aiBox;

au-tax-mcp-server calls payday-super-checker and ato-benchmark-compare. australian-accounting-skills names the payday-super CLI rather than inventing the same work. Historical engine repositories stay the source of truth for the calculation; the products above are what a stranger should install.

• au-tax-mcp-server (aus-accounting-mcp) - Unified Model Context Protocol (MCP) server exposing ATO small business benchmarks, Payday Super statutory timelines, and synthetic SBR test payloads to Claude Desktop, Claude Code, Cursor, and Antigravity. Refuses Division 7A calculations by design. Preparation aid only, not tax advice.

• Ozzit - 130 native Excel LAMBDA functions for dynamic-array financial modelling. Derivative of Craig Hatmaker's Financial Starter Pack; this repo adds Australian GST/FY helpers. See ATTRIBUTION.md. Not an individual-tax or Division 7A engine.
• TheExchequerTally (Corporate Tax & Franking) - Corporate tax rate determination (Base Rate Entity eligibility under s 23AA ITRA 1986), Franking Account Balance (FAB) tracking, and Division 203 benchmark rule compliance.
• SolomonsSword (Trust Income & Section 100A) - Trust income allocation under Division 6 ITAA 1936 (Bamford proportionate approach), Section 100A risk classification (ATO PCG 2022/2), and Section 99B foreign trust receipt analysis.
• payday-super-checker - Experimental Payday Super 2026 contribution-timing review and SG-charge estimates. Not a compliance determination.
• ato-benchmark-compare - Localised, offline profit-and-loss variance analysis against Australian Taxation Office (ATO) small business benchmarks.

• DrDebits - Primary-source-grounded ethical guardrails (aligned with APES 110 and TPB Code of Professional Conduct) for LLM-assisted taxation workflows.
• xero-ai-review-gateway - Zero-network, fixed-policy safety boundary for AI-assisted trial balance review with cryptographic receipt verification and data minimisation.
• australian-accounting-skills - Nine modular agent skills for Australian public practice (BAS reconciliation, FBT, Division 7A loan-register workflow, STP year-end finalisation, and 13-week cash flow modelling).
• hardhat-ledger - Claude Code skills for Australian construction and mining subcontractors (Security of Payment claims, retentions, WIP, Coal LSL, and Fuel Tax Credits).

• xero-trial-balance-export - Exports reconciled Xero trial balances to validated CSV formats with strict movement and year-to-date mathematical integrity.
• accounting-excel-toolkit - Power Query (M) and VBA automation utilities for Australian accounting, reconciliations, and month-end financial reporting pipelines.
• monthly-close-control-plane - Local trial-balance review packs with exception surfacing; it does not approve or lock a close.
• awesome-australian-accounting-tech - A curated index of open-source libraries, computational tax engines, ATO datasets, and Commonwealth legislation APIs.

• Meltano SDK #3727 - Preservation of OAuth refresh tokens returned by token refresh endpoints.
• tap-xero #20 - Corrected OAuth 2.0 configuration examples in the docs.
• OpenAccountants - Australian taxation guidance, validation test harnesses, and CI automation for AI agent tax guides.
• Sophia Script for Windows #737 - Moved localisation strings that had been copied into the wrong language files.

1. Primary Source Grounding: Computations that actually ship (Payday Super timing and experimental SG-charge estimates, ATO benchmark ratios, company tax/franking, trust allocation) are grounded in the cited Commonwealth legislation, ATO public rulings, and AASB/APESB standards. This account does not ship an individual marginal-tax or Medicare-levy engine.
2. Exact Decimal Arithmetic: Computational outputs use exact decimal quantisation to prevent binary floating-point drift.
3. Local Privacy Boundaries: Client-sensitive financial data remains in local memory or zero-network sandboxes; public fixtures use synthetic data only.
4. Human-in-the-Loop Signoff: Algorithmic pipelines automate calculation and structural validation; ultimate professional judgement and statutory lodgment remain strictly human-controlled.