# Quaderno

**Canonical:** https://apis.io/providers/quaderno/  
**Website:** https://quaderno.io  
**APIs profiled:** 14

Quaderno is a tax compliance, invoicing, and sales-tax / VAT automation platform. Its REST API calculates the correct sales tax, VAT, and GST in real time for any jurisdiction, then issues tax-compliant invoices, credit notes, estimates, and receipts. The account-scoped API (https://ACCOUNT_NAME.quadernoapp.com/api) covers contacts, items, invoices, credits, estimates, expenses, recurring documents, payments, unified sales transactions, hosted Checkout sessions, and webhooks, plus a tax engine for rate calculation, jurisdictions, tax codes, and tax ID validation. Requests use HTTP Basic Auth with a private API key and return JSON; every endpoint path ends in .json.

## Kin Score — 38.2 / 100 (thin)

Scored 2026-08-25 under rubric 0.14.0. Trend: flat (+0.0 from 38.2).

| Facet | Score |
|---|---|
| Discoverability | 74.1 |
| Contract Quality | 56.7 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 34.2 |
| Developer Ergonomics | 21.4 |
| Commercial Clarity | 39.5 |
| Access Clarity | 39.5 |

## Agent readiness — 19.8 (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 | no |
| 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 (free trial) · Self-serve signup — onboarding: self-serve, pricing: freemium, trial: yes (confidence: high).

## APIs (14)

- **Quaderno Authentication API** — Ping the API and inspect the authenticated account and rate-limit state.
- **Quaderno Checkout API** — Hosted checkout sessions for collecting tax-compliant payments.
- **Quaderno Contacts API** — Customers and vendors.
- **Quaderno Credits API** — Credit notes issued against invoices.
- **Quaderno Estimates API** — Quotes and estimates issued to customers.
- **Quaderno Evidences API** — Location evidence records supporting tax determination for a transaction.
- **Quaderno Expenses API** — Purchases and vendor bills recorded against the account.
- **Quaderno Invoices API** — Sales invoices issued to customers.
- **Quaderno Items API** — Reusable products and services used as document line items.
- **Quaderno Payments API** — Payments recorded against invoices, credits, and expenses.
- **Quaderno Recurring API** — Recurring document templates that auto-generate invoices.
- **Quaderno Taxes API** — Real-time tax rate calculation, jurisdictions, tax codes, and tax ID validation.
- **Quaderno Transactions API** — Unified sales transactions that both record a sale and calculate tax.
- **Quaderno Webhooks API** — Subscriptions that deliver real-time event notifications to your app.

## Agentic access (1)

- **Quaderno Agentic Access** — 53 operations · 28 acting

## Security (2)

- **Quaderno Authentication** — http · 1 scheme
- **Quaderno Domain Security** — TLSv1.3 · DMARC

## Plans (1)

- **Quaderno Plans Pricing**

## Tags

Tax Compliance, Sales Tax, VAT, Invoicing, Billing, Fintech

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