Fiz Invoicing Skill

FIZ Invoicing — Claude Code / Agent Skill

**Emitir faturas em Portugal com IA.** Skill para [Claude Code](https://claude.com/claude-code) que emite **faturas, faturas-recibo e faturas simplificadas** através da [API pública da FIZ](https://api.fiz.co) — cria clientes e artigos, aplica a **taxa de IVA** correta por território, o **motivo de isenção** certo, retenção na fonte, e comunica o documento à **Autoridade Tributária (AT)**. *Faturação automática para freelancers e empresas, em linguagem natural.*

A [Claude Code](https://claude.com/claude-code) skill that lets you issue invoices through the [FIZ](https://fiz.co) Public API by just asking in plain language — *"bill João 10 consulting hours"*, *"issue a fatura-recibo for this customer"*, *"download the PDF for invoice X"*.

**Prefer not to manage an API key?** FIZ also ships an **MCP connector** at `https://api.fiz.co/mcp` — connect it to Claude or ChatGPT with OAuth and skip the setup below. See [Two ways to use FIZ with AI](#two-ways-to-use-fiz-with-ai).

It follows the [Agent Skills](https://agentskills.io) open standard, so it is not locked to one tool: install it in Claude Code today, and it works with any agent runtime that supports the standard. It is **Claude-Code-first**, though — the `SKILL.md` frontmatter uses a couple of Claude Code extensions to the standard (`allowed-tools`, and `${CLAUDE_SKILL_DIR}` for the helper path); spec-compliant runtimes ignore the extra frontmatter, and the helper falls back to an absolute skill path. (Setup notes here are written for Claude Code; other runtimes load `fiz-invoicing/SKILL.md` the same way.)

The skill teaches the agent both the **API mechanics** (endpoints, fields, auth) and the **Portuguese tax domain** behind invoicing (VAT rates per territory, when an exemption code is required and which one, CAE/NIF rules, withholding tax, and why issuing is irreversible) — so it builds *correct* fiscal documents, not just well-formed JSON.

**Keyw