# Fortnox

**Canonical:** https://apis.io/providers/fortnox/  
**Website:** https://www.fortnox.se  
**APIs profiled:** 12

Fortnox is a Swedish cloud accounting, ERP, and business-administration platform for small and medium-sized businesses and accounting bureaus. Its REST API at https://api.fortnox.se/3/ programmatically manages accounting and financial data - invoices, customers, articles, orders, offers, vouchers, accounts, suppliers, supplier invoices, projects, and financial years - authenticated with OAuth2 Authorization Code Flow. Fortnox also publishes a duplex WebSocket event stream at wss://ws.fortnox.se/topics-v1 that pushes minimal change notifications across domains so integrations can react to changes instead of polling.

## Kin Score — 39.3 / 100 (developing)

Scored 2026-08-24 under rubric 0.13.0. Trend: flat (-0.4 from 39.7).

| Facet | Score |
|---|---|
| Discoverability | 74.1 |
| Contract Quality | 59.4 |
| Governance | 13.6 |
| Contract Governance | 13.6 |
| Operational Transparency | 21.1 |
| Developer Ergonomics | 23.8 |
| Commercial Clarity | 39.5 |
| Access Clarity | 39.5 |

## Agent readiness — 20.9 (agent-aware)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | bearer |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | documented |
| Event Surface Described | derived |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |
| Delegated Identity | no |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |

## Access

Freemium · Self-serve signup — onboarding: self-serve, pricing: freemium, trial: no (confidence: high).

## APIs (12)

- **Fortnox Topics WebSocket API** — Duplex WebSocket stream at wss://ws.fortnox.se/topics-v1 that pushes minimal change-notification events across domains (invoices, supplier-invoices, customers, articles, orders,...
- **Fortnox Accounts API** — Chart of accounts.
- **Fortnox Articles API** — Article (product/service) register.
- **Fortnox Customers API** — Customer register.
- **Fortnox Financial Years API** — Financial (accounting) years.
- **Fortnox Invoices API** — Accounts-receivable customer invoices.
- **Fortnox Offers API** — Offers (quotations).
- **Fortnox Orders API** — Sales orders.
- **Fortnox Projects API** — Projects for tagging and reporting.
- **Fortnox Supplier Invoices API** — Inbound accounts-payable supplier invoices.
- **Fortnox Suppliers API** — Supplier register.
- **Fortnox Vouchers API** — Accounting vouchers (journal entries).

## Agentic access (1)

- **Fortnox Agentic Access** — 42 operations · 21 acting

## Security (2)

- **Fortnox Authentication** — oauth2/apiKey · 3 schemes
- **Fortnox Domain Security** — TLSv1.3 · HSTS · DMARC

## Plans (1)

- **Fortnox Plans Pricing**

## Tags

Accounting, ERP, Invoicing, Bookkeeping, Sweden, Nordics, Finance, Vouchers, Customers, Software-as-a-Service

---

Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/fortnox/). Scores are computed from the provider's own public artifacts under a published rubric.