Description

n8n-nodes-fortnox

This is an n8n community node for Fortnox, the Swedish accounting and invoicing platform. It lets you use n8n to automate work against the Fortnox REST API.

n8n is a fair-code licensed workflow automation platform.

Installation · Credentials · Operations · Usage · Compatibility · Resources

Installation

Follow the n8n community nodes installation guide.

In short, in your n8n instance go to Settings > Community Nodes, select Install, and enter @peterhelge/n8n-nodes-fortnox.

Credentials

This node authenticates using Fortnox OAuth2 API credentials, implemented on top of n8n’s generic OAuth2 credential type.

You need a Fortnox Developer account and an app registered in the Fortnox Developer Portal:

1. Log in to the Fortnox Developer Portal and create a new app.
2. Set the app’s Redirect URI to the callback URL n8n shows you when creating the credential (typically https:///rest/oauth2-credential/callback).
3. Note the app’s Client ID and Client Secret.
4. In n8n, create a new credential of type Fortnox OAuth2 API and enter the Client ID and Client Secret.
5. Click Connect my account and complete the Fortnox login/consent flow.

Notes on how the credential is wired up, in case you need to troubleshoot:

• Fortnox uses the standard OAuth2 Authorization Code flow. The authorization URL and token URL are pre-filled and hidden in the credential (https://apps.fortnox.se/oauth-v1/auth and https://apps.fortnox.se/oauth-v1/token).
• The scope is fixed to invoice companyinformation customer. Each one must be enabled as a permission (“Faktura”, “Företagsinformation” and “Kund” under “Behörigheter”) on your app in the Fortnox Developer Portal, or the OAuth flow fails with invalid_scope. If you extend this node to cover more resources, you’ll need to add both the scope here and the matching permission on the app (and re-authorize the credential).
• The credential sends access_type=offline on the authorization request, which is required by Fortnox to issue a refresh token.
• Fortnox’s access tokens are valid for 1 hour, and refresh tokens for 45 days. Refresh tokens are rotated on every use — n8n’s OAuth2 credential handles this automatically, but if you ever request a token manually outside n8n with the same credential, you can invalidate n8n’s stored refresh token.

Operations

Customer

• Get — Retrieve a single customer by customer number (e.g. the CustomerNumber field on an invoice), including contact details such as address, email and phone.

Invoice

• Get — Retrieve a single invoice by its Fortnox document number.
• Get Many — List invoices, with optional filters:

– Filter: one of Fortnox’s predefined filters (unpaid, unpaidoverdue, fullypaid, cancelled, unbooked).
– Customer Number, From Date, To Date.
– Return All or a Limit on the number of results.

• Get PDF — Download an invoice as a PDF file (binary output), using Fortnox’s print endpoint.

Usage

A minimal workflow:

1. Add a Fortnox node.
2. Select credentials of type Fortnox OAuth2 API.
3. Resource: Invoice, Operation: Get Many, Filter: Unpaid.
4. Run the node to list all unpaid invoices.

To fetch one specific invoice, set Operation to Get and enter its Document Number (the value in Fortnox’s DocumentNumber field, e.g. 204).

To get the customer’s contact details for an invoice, take the invoice’s CustomerNumber field and feed it into a second Fortnox node with Resource: Customer, Operation: Get.

To download an invoice as a PDF (e.g. to attach to an email), set Operation to Get PDF and enter its Document Number. The output item carries the PDF as binary data under the data key.

If you’re new to n8n, see the Try it out guide to get a workflow running end to end.

Compatibility

Built and tested against n8n’s current community node API (n8nNodesApiVersion: 1). Requires Node.js 20+ (matching current n8n runtime requirements).

Known limitations / things to verify

This is a first (v1) release, scoped deliberately small. A few things depend on details of the live Fortnox API that should be double-checked against your own Fortnox account before relying on this in production:

• Pagination assumes Fortnox’s list responses include a MetaInformation.@TotalPages field. This matches Fortnox’s documented pagination pattern, but hasn’t been verified against a live response with more than one page of invoices.
• Scopes: the credential requests invoice companyinformation customer. Each must be enabled as a permission (“Faktura”, “Företagsinformation” and “Kund” under “Behörigheter”) on your app in the Fortnox Developer Portal, or authorization will fail with invalid_scope.
• Only the fields documented by Fortnox as stable filters are exposed (filter, customernumber, fromdate, todate). Fortnox’s API has more query parameters (e.g. account range, cost center) that could be added later.
• Get PDF assumes Fortnox’s /invoices/{DocumentNumber}/print endpoint returns a raw PDF when the request sends Accept: application/pdf (Fortnox’s documented convention for print endpoints across resources). This hasn’t been confirmed against a live response — verify the downloaded file actually opens as a valid PDF before relying on it.

Roadmap (not in this release)

Ideas for a v2, intentionally left out to keep v1 small and finished:

• Polling trigger for new/updated invoices (using Fortnox’s lastmodified filter or a webhook where available).
• More resources: Payments, Vouchers/Articles.
• Get Many / Create / Update operations for Customers (this release is read-only, single-record).
• Create/Update operations for Invoices (this release is read-only).

Resources

• n8n community nodes documentation
• Fortnox Developer Portal
• Fortnox API reference

License

MIT

Author

Built and maintained by Peter Helge at Klarar, free tools for Swedish small businesses: cash flow, quotes and employer contributions.