Quick answer
Yes — an AI agent can generate invoices with Invovate. The agent sends a JSON invoice (from, to, items) to POST https://invovate.com/api/generate-invoice and gets back computed totals as JSON, a PDF, or UBL 2.1 XML in under a second. An OpenAPI 3.1 spec at https://invovate.com/openapi.json can be imported directly as a ChatGPT or Claude Action, or wrapped as an MCP tool.
- Endpoint
POST /api/generate-invoice- Input
- JSON —
from,to,items(snake_case or camelCase) - Output
"json"·"pdf"·"ubl"- Auth
Authorization: Bearer inv_…(JSON works anonymously; PDF/UBL need a free key)- Spec
- OpenAPI 3.1 at
/openapi.json— ChatGPT/Claude Action & MCP ready - Agent-safe
Idempotency-Keyretries, HMAC webhooks, batch up to 50- Languages
- 11 incl. Arabic (RTL), Japanese, Hindi, Cyrillic · 20+ currencies
- Cost
- Free tier — no credit card
Why agents need a dedicated invoice tool
Large language models are good at extracting invoice details from a conversation or a document, but they cannot reliably render a pixel-perfect, multilingual PDF or a schema-valid UBL file on their own. Invovate is the deterministic “last mile”: the agent assembles the data, calls one endpoint, and gets a correct, downloadable invoice back — with the math computed server-side so totals, tax and discounts are always right.
What the API gives an agent
| Capability | Invovate |
|---|---|
| Structured JSON input | Yes — from, to, items, taxes, discounts |
| PDF output | Yes — "output":"pdf", 5 templates |
| JSON totals output | Yes — "output":"json" (anonymous OK) |
| UBL 2.1 XML output | Yes — "output":"ubl" |
| OpenAPI 3.1 spec | Yes — /openapi.json, stable operationIds |
| Idempotent retries | Yes — Idempotency-Key header |
| Webhooks | Yes — HMAC-signed, create/list/delete |
| Batch generation | Yes — up to 50 invoices per call |
| Multilingual / RTL rendering | Yes — 11 languages, Arabic RTL, CJK, Devanagari, Cyrillic |
| Shareable hosted link + QR | Yes — 7-day signed link |
| Free self-serve API key | Yes — issued instantly in the dashboard |
| Regulated e-invoice transmission (Peppol, etc.) | No — document generation only (see note below) |
Agent quickstart
The minimal call needs no auth and returns computed totals — perfect for an agent to validate input before rendering:
# JSON totals — no API key required curl -X POST https://invovate.com/api/generate-invoice \ -H "Content-Type: application/json" \ -d '{ "from": { "name": "Acme LLC" }, "to": { "name": "Globex Corp" }, "items": [ { "description": "Consulting", "quantity": 2, "unit_price": 150 } ] }' # -> { "success": true, "invoice": { "grand_total": 300, ... } }Add a free API key and "output":"pdf" (or "ubl") to get a file back. Send an Idempotency-Key so a retry never double-creates:
# PDF output — needs a free API key curl -X POST https://invovate.com/api/generate-invoice \ -H "Authorization: Bearer inv_YOUR_KEY" \ -H "Content-Type: application/json" \ -H "Idempotency-Key: agent-run-8f3c2" \ -d '{ "from": { "name": "Acme BV", "tax_id": "NL0012" }, "to": { "name": "Client KK" }, "language": "ja", "currency": "JPY", "template": "modern", "items": [ { "description": "デザイン", "quantity": 8, "unit_price": 15000, "tax_rate": 10 } ], "output": "pdf" }' --output invoice.pdfConnect it to your agent platform
ChatGPT (custom GPT Action)
Import https://invovate.com/openapi.json as an Action. Use a user-provided API key for auth — do not ship a shared key in a public GPT.
Claude (tool / Action)
Point a Claude tool at the same OpenAPI spec, or call the endpoint directly. The stable operationIds map cleanly to tool names.
MCP server
Wrap the endpoints as MCP tools (e.g. calculate_invoice_totals, generate_invoice_pdf, generate_invoice_ubl) so any MCP-capable agent can call them.
Postman / anything OpenAPI
The 3.1 spec imports into Postman, RapidAPI, or any OpenAPI client for instant request scaffolding.
Example agent prompt
A natural-language instruction an agent can act on end-to-end:
“Create an invoice for Acme BV billing Client KK for 3 consulting days at €900/day, Dutch BTW 21%, paid by bank transfer, in English, and give me a PDF.”The agent maps that to a JSON body (from, to, items, currency, tax_rate, output:"pdf"), calls the endpoint, and returns the PDF or a 7-day shareable link.
Frequently asked questions
Can an AI agent generate invoices with Invovate?
Yes. The agent posts a JSON invoice to POST /api/generate-invoice and receives JSON totals, a PDF, or UBL 2.1 XML. The OpenAPI 3.1 spec makes it importable as a ChatGPT/Claude Action or an MCP tool.
Does it output PDF and UBL, not just JSON?
Yes — "output" can be json, pdf, or ubl. JSON is available anonymously (rate-limited); PDF and UBL require a free API key.
Does it render non-Latin scripts correctly?
Yes — proper Noto Sans fonts are embedded for Arabic (RTL), Japanese, Hindi (Devanagari), and Russian (Cyrillic), with mixed Latin text handled cleanly.
Is it safe for automated retries?
Yes — send an Idempotency-Key header and a retried request returns the original result instead of creating a duplicate invoice.
See real output
Sample invoices generated by this exact API — download and inspect them:
- PDF: English VAT · Dutch BTW · German USt · Arabic RTL · Japanese 消費税 · Hindi GST
- Other: UBL 2.1 XML · sample request JSON · webhook payload · asset README
Related developer pages
- Invoice API documentation — full schema, error codes, rate limits
- OpenAPI 3.1 spec — import into ChatGPT/Claude/Postman/MCP
- Invoice-Generator.com API alternative
- Get a free API key · Limits & plans
Not regulated e-invoicing. Invovate generates invoice documents (PDF, JSON, UBL 2.1) but is not a regulated electronic-invoice transmission service. It does not provide Peppol, Factur-X, ZUGFeRD, XRechnung, EN 16931, SAF-T, or NF-e/SEFAZ compliance or government-network delivery. UBL export is for interoperability and archival only. You remain responsible for any regulated e-invoicing obligations that apply to you.