Quaderno
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.
Quaderno publishes 14 API contracts indexed on the APIs.io network, including Authentication API, Checkout API, Contacts API, and 11 more. Tagged areas include Tax Compliance, Sales Tax, VAT, Invoicing, and Billing.
The Quaderno catalog on APIs.io includes 1 Spectral governance ruleset.
Quaderno’s developer surface includes authentication, documentation, and 10 more developer resources.
What this lets a business do 3
Business capabilities this provider's published APIs can perform, derived from its own contracts. Browse all capabilities →
Kin Score
Markets this provider is in provisional
The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.
| Market | Position | Depth | Registered MCP server | Declares compatibility |
|---|---|---|---|---|
| Commerce Platform Ecosystems (Shopify, WooCommerce, Stripe Apps) | builds-on | 29.2 | - | - |
| E-invoicing and Tax Compliance (certified operators) | builds-on | 29.2 | - | - |
| Stripe App Marketplace and Partner Ecosystem (builders on Stripe) | builds-on | 29.2 | - | - |
| Amazon Seller Ecosystem (Selling Partner Appstore, Amazon Ads partners) | builds-on | 29.2 | - | - |
| Xero App Store (SMB finance, payroll, inventory and invoicing apps built on Xero, by region) | builds-on | 29.2 | - | - |
Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.
Standards implemented 1
Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.
APIs 14
Individual APIs this provider publishes, each with its own machine-readable definition.
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.
Scroll for all 14
Open Collections 15
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
Quaderno Authentication API
OPEN COLLECTIONQuaderno Authentication Checkout API
OPEN COLLECTIONQuaderno Authentication Contacts API
OPEN COLLECTIONQuaderno Authentication Credits API
OPEN COLLECTIONQuaderno Authentication Estimates API
OPEN COLLECTIONQuaderno Authentication Evidences API
OPEN COLLECTIONQuaderno Authentication Expenses API
OPEN COLLECTIONQuaderno Authentication Invoices API
OPEN COLLECTIONQuaderno Authentication Items API
OPEN COLLECTIONQuaderno Authentication Payments API
OPEN COLLECTIONQuaderno Authentication Recurring API
OPEN COLLECTIONQuaderno Authentication Taxes API
OPEN COLLECTIONQuaderno Authentication Transactions API
OPEN COLLECTIONQuaderno Authentication Webhooks API
OPEN COLLECTIONQuaderno API
OPEN COLLECTIONScroll for all 15
Quaderno API pricing
Not yet checked against Quaderno's own pricing page. Compiled by API Evangelist on 2026-07-03 from quaderno.io/pricing/; confirm before you rely on a figure.
| Plan | Price |
|---|---|
| Free Trial trial | — |
| Startup paid | — |
| Business paid | — |
| Growth paid | — |
| Enterprise enterprise | — |
Plan details, limits and sources →
Rate limits
- API Requests: 100 per 15 seconds requests
- Ping: no rate-limit cost requests
- Monthly Transactions: per plan transactions
Compiled by API Evangelist, not yet checked against Quaderno's documentation. Rate-limit details →
Pricing Plans 1
Published pricing tiers and plan structures.
Rate Limits 1
Documented rate limits and quota policies.
Quaderno Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals for API financial operations.
Quaderno Finops
FINOPSSpectral Rules 1
Spectral governance rulesets for linting and validating these APIs. Counts are the severity each rule declares, not results of running them.
Quaderno API Rules
SPECTRALSecurity Posture 2
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access (API Evangelist recommendations) 1
Recommended x-agentic-access execution contracts for AI agents.
Resources
Documentation 1
Reference material describing how the API behaves
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 2
Authentication, authorization, and security posture
Operate 1
Status, limits, changes, and where to get help
Commercial 2
Pricing, plans, and the legal terms of use
Company 3
The organization behind the API
Other 1
Properties that don't map to a standard resource type
Source (apis.yml)
Quaderno API — frequently asked questions
Does Quaderno have an API?
Yes. APIs.io lists 14 APIs from Quaderno, including Quaderno Authentication API, Quaderno Checkout API and Quaderno Contacts API, and 11 more.
Is there an OpenAPI specification for the Quaderno API?
Yes. APIs.io indexes 14 OpenAPI specifications for Quaderno, each linked for download from this page.
How do I authenticate with the Quaderno API?
Quaderno uses bearer-token authentication (http · 1 scheme). The details are profiled on APIs.io as Quaderno Authentication.
How much does the Quaderno API cost?
APIs.io lists 5 pricing plans for Quaderno, with each plan's price, limits and inclusions under Pricing on this page.
Is the Quaderno API ready for AI agents?
Quaderno has a Kin Score of 27.8 out of 100 (thin) and an Agent Readiness score of 20.7 (agent-aware), scored by API Evangelist on 2026-11-13.
Work with this as data
Every provider here is available over the APIs.io API and to AI agents over MCP.