Choose Your Path

Every integration starts with the same Quickstart: sign up, create one entity, generate a sandbox key, and issue one sandbox invoice. This page helps you choose what to build on top of that.

Single-business developers are welcome

One business with one issuing entity is a complete Space Invoices setup. You do not need a platform architecture or a sales call to start. Create one entity, pick a path below, and go live when your sandbox tests pass.

Compare The Four Paths

	JavaScript SDK	Embed SDK	React UI	Direct REST API
Best for	Backend workflows you control	Working invoicing screens in an existing app	React teams that want to own the UI code	Any language, or teams writing their own client
What you build	Your own UI, or none	A container element on your page	Screens, from components you copy into your app	HTTP requests and client code
Key	Account or entity key, on your server	Entity key (ek_*)	Account or entity key, on your server	Account or entity key, on your server
Backend needed	Yes	Usually	Yes	Yes
Typical time to first invoice	Half a day to 2 days	A few hours	1 to 3 days	1 to 3 days
Start here	JavaScript SDK quickstart	Embed SDK quickstart	React UI getting started	Authentication, then the Create Invoice API

Pick The JavaScript SDK If

• you want typed backend workflows for invoices, customers, items, payments, or exports
• you need your own UI, or no UI at all
• you want the shortest route from a sandbox proof of concept to production

Initialize once on the server, then create an invoice in your entity:

Initialize SDKtypescript

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import SpaceInvoices from "@spaceinvoices/js-sdk/sdk";

const sdk = new SpaceInvoices("YOUR_API_KEY");

Personalize locallyChecked with SDK v14.25.0

Create invoicetypescript

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const invoice = await sdk.invoices.create({
  customer: {
    name: "Acme Corporation",
    email: "billing@acme.com",
  },
  items: [
    {
      name: "Consulting",
      quantity: 10,
      price: 150,
    },
  ],
}, { entity_id: "YOUR_ENTITY_ID" });

Personalize locallyChecked with SDK v14.25.0

Create Invoice API →

Not ideal if you want a ready-made invoicing interface this week.

Next: JavaScript SDK quickstart and the Quickstart.

Pick The Embed SDK If

• you want invoicing screens in your app without owning frontend component code
• you need the shortest path to a working embedded UI
• an iframe-based integration boundary is acceptable

Add a container, then open the invoice list inside it:

Quick Starttypescript

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import { SpaceInvoices } from "@spaceinvoices/embed-sdk";

const si = new SpaceInvoices({
  apiKey: "ek_live_your_entity_api_key",
  entityId: "ent_123",
  onAction: (_action) => {},
});

// Open invoice list in the container
si.open("invoices", { container: "#space-invoices-embed" });

Personalize locally

Not ideal if you need deep DOM-level customization or want the components to follow your own design system. Choose the React UI for that.

Next: Embed SDK quickstart and User Access.

Pick The React UI If

• you already ship React
• you want copy-paste components you own and can change
• you need more flexibility than an embed, without building every screen from scratch

Add the kit with its installer, then pick the screens you need:

npx @spaceinvoices/react-ui@latest init
npx @spaceinvoices/react-ui@latest add invoices/create-invoice-screen

Not ideal if your team is not on React or you want a UI that needs no maintenance.

Next: React UI getting started and Providers.

Pick The Direct REST API If

• your backend is not JavaScript
• you want raw HTTP without SDK abstractions
• you need full control over transport, auth, and client generation

Create an invoice in one entity. The x-entity-id header selects the entity:

curl -X POST "https://eu.spaceinvoices.com/invoices" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "x-entity-id: YOUR_ENTITY_ID" \
  -H "Content-Type: application/json" \
  -d '{
    "items": [
      { "name": "Consulting", "quantity": 10, "price": 150 }
    ]
  }'

Next: Authentication to choose your key type, then the API reference.

Zapier, If You Do Not Write Code

Zapier creates invoices or estimates from CRM, forms, or spreadsheets with no backend work. It does not offer embedded UI or custom backend logic. See Zapier.

Choose By Product Shape

If your product looks like this	Start here
One business, one issuing entity	Quickstart
One platform, many customer businesses	Multi-Tenancy
You need end-user dashboard access	User Access
You want the docs mapped to your market	Use Cases

Sandbox And Production

Sandbox and production are separate environments with separate keys and data. Sandbox is free for building and testing. Production is billed.

	Sandbox	Production
Cost	Free, with no time limit	€49/month platform fee
Entities	Sandbox entities	The first entity has no per-entity charge; each additional entity is €3/month
Documents	Test data only	100 documents per entity per month are included, then billed per document
Keys	sk_sandbox_*, ek_sandbox_*	sk_live_*, ek_live_*
Email	Sandbox send limits apply, see Email	Live delivery to your customers

Current rates are on spaceinvoices.com/pricing.

Recommended default

Start with the JavaScript SDK and a sandbox entity. It gives the clearest path from proof of concept to production and keeps your options open.

What The First Week Usually Looks Like

1. Sign up and create a sandbox entity.
2. Generate the key type that matches your path.
3. Issue one sandbox invoice.
4. Confirm rendering, tax behavior, and the delivery flow.
5. Decide how your end users will access invoicing, if applicable.

Next Steps

• Introduction: confirm the product model
• Quickstart: create the first invoice
• Use Cases: match the docs to your architecture