I built a CLI to programmatically interact with Spain's tax agency (AEAT) for income tax filing (Modelo 100). It authenticates via Cl@ve using Playwright, downloads your tax data, validates XML against the official XSD, and uploads it to AEAT's EDFI system for reconciliation. The problem: AI agents can do a good job organizing financial data from multiple brokers, banks and crypto exchanges, but there was no way to programmatically check that against what the tax agency already knows about you. This CLI bridges that gap. It does NOT file or submit anything. The user is always responsible for manual review and submission.

Maybe a bit specific for the spanish community, but if you always wish there was a CLI to do your taxes here is an unofficial one.