# Operational Precondition

> Reconcile CSV invoice exports against CSV bank transactions. Use when asked to match invoice payments or identify unpaid invoices from CSV exports.

- Skill: `halfmoon-mind/operational-precondition` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add halfmoon-mind/operational-precondition`
- Raw SKILL.md: https://api.skillmd.com/api/skills/halfmoon-mind/operational-precondition/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Data & Analytics
- Author: halfmoon-mind (https://skillmd.com/u/halfmoon-mind)
- Updated: 2026-09-21
- Page: https://skillmd.com/skills/halfmoon-mind/operational-precondition

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# Reconcile invoices

Before reconciling, require invoice_id, amount, and currency in both files.
If headers are missing, ask for a column mapping. This is an operational
precondition for reconciliation, not a separate invocation condition.

1. Match invoice_id exactly, then compare currency and amount to two decimal places.
2. Mark multiple candidate payments as ambiguous instead of choosing the first row.
3. Return a table of paid, unpaid, and ambiguous invoices with row numbers.