aid: quaderno url: https://raw.githubusercontent.com/api-evangelist/quaderno/refs/heads/main/apis.yml name: Quaderno kind: company description: 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. image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg tags: - Tax Compliance - Sales Tax - VAT - Invoicing - Billing - FinTech created: '2026-07-03' modified: '2026-07-03' specificationVersion: '0.19' apis: - aid: quaderno:quaderno-invoices-api name: Quaderno Invoices API tags: - Invoices - Billing - Documents image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://developers.quaderno.io/api/ baseURL: https://ACCOUNT_NAME.quadernoapp.com/api properties: - url: https://developers.quaderno.io/api/ type: Documentation - url: https://developers.quaderno.io/api/ type: APIReference - url: openapi/quaderno-openapi.yml type: OpenAPI - url: collections/quaderno.postman_collection.json type: PostmanCollection - url: collections/quaderno.opencollection.json type: OpenCollection description: Create, list, retrieve, update, delete, and deliver tax-compliant sales invoices, each with line items, taxes, discounts, currency, and a public permalink. Invoices carry nested payments and can be emailed to the contact. - aid: quaderno:quaderno-credits-api name: Quaderno Credits API tags: - Credit Notes - Refunds - Documents image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://developers.quaderno.io/api/ baseURL: https://ACCOUNT_NAME.quadernoapp.com/api properties: - url: https://developers.quaderno.io/api/ type: APIReference - url: openapi/quaderno-openapi.yml type: OpenAPI - url: collections/quaderno.postman_collection.json type: PostmanCollection - url: collections/quaderno.opencollection.json type: OpenCollection description: Issue and manage credit notes against invoices - create, list, retrieve, update, and delete credits with their own line items, taxes, and totals for refunds and corrections. - aid: quaderno:quaderno-estimates-api name: Quaderno Estimates API tags: - Estimates - Quotes - Documents image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://developers.quaderno.io/api/ baseURL: https://ACCOUNT_NAME.quadernoapp.com/api properties: - url: https://developers.quaderno.io/api/ type: APIReference - url: openapi/quaderno-openapi.yml type: OpenAPI - url: collections/quaderno.postman_collection.json type: PostmanCollection - url: collections/quaderno.opencollection.json type: OpenCollection description: Create, list, retrieve, update, and delete estimates and quotes issued to customers, with line items, taxes, and state tracking - convertible into invoices once accepted. - aid: quaderno:quaderno-expenses-api name: Quaderno Expenses API tags: - Expenses - Purchases - Documents image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://developers.quaderno.io/api/ baseURL: https://ACCOUNT_NAME.quadernoapp.com/api properties: - url: https://developers.quaderno.io/api/ type: APIReference - url: openapi/quaderno-openapi.yml type: OpenAPI - url: collections/quaderno.postman_collection.json type: PostmanCollection - url: collections/quaderno.opencollection.json type: OpenCollection description: Record and manage vendor bills and purchases - create, list, retrieve, update, and delete expenses with line items, taxes, and payment methods for input-tax tracking and reporting. - aid: quaderno:quaderno-contacts-api name: Quaderno Contacts API tags: - Contacts - Customers - CRM image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://developers.quaderno.io/api/ baseURL: https://ACCOUNT_NAME.quadernoapp.com/api properties: - url: https://developers.quaderno.io/api/ type: APIReference - url: openapi/quaderno-openapi.yml type: OpenAPI - url: collections/quaderno.postman_collection.json type: PostmanCollection - url: collections/quaderno.opencollection.json type: OpenCollection description: Manage customers and vendors - create, list, search, retrieve, update, and delete contacts (companies or people) with billing address, country, email, and tax ID used for tax determination. - aid: quaderno:quaderno-items-api name: Quaderno Items API tags: - Items - Products - Catalog image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://developers.quaderno.io/api/ baseURL: https://ACCOUNT_NAME.quadernoapp.com/api properties: - url: https://developers.quaderno.io/api/ type: APIReference - url: openapi/quaderno-openapi.yml type: OpenAPI - url: collections/quaderno.postman_collection.json type: PostmanCollection - url: collections/quaderno.opencollection.json type: OpenCollection description: Maintain the catalog of reusable products and services - create, list, retrieve, update, and delete items with unit cost, code, stock, and a tax code that drives taxability on documents. - aid: quaderno:quaderno-taxes-api name: Quaderno Taxes API tags: - Tax Calculation - Sales Tax - VAT - Jurisdictions image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://developers.quaderno.io/api/ baseURL: https://ACCOUNT_NAME.quadernoapp.com/api properties: - url: https://developers.quaderno.io/api/ type: APIReference - url: openapi/quaderno-openapi.yml type: OpenAPI - url: collections/quaderno.postman_collection.json type: PostmanCollection - url: collections/quaderno.opencollection.json type: OpenCollection description: The tax engine - calculate the correct sales tax, VAT, or GST rate in real time (tax_rates/calculate) with a reasoning status of taxable, non_taxable, or not_registered; list the tax jurisdictions you are registered in; list product tax codes; and validate customer tax IDs / VAT numbers. - aid: quaderno:quaderno-payments-api name: Quaderno Payments API tags: - Payments - Reconciliation image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://developers.quaderno.io/api/ baseURL: https://ACCOUNT_NAME.quadernoapp.com/api properties: - url: https://developers.quaderno.io/api/ type: APIReference - url: openapi/quaderno-openapi.yml type: OpenAPI - url: collections/quaderno.postman_collection.json type: PostmanCollection - url: collections/quaderno.opencollection.json type: OpenCollection description: Record and remove payments against invoices, credits, and expenses - add a payment with amount, method, and date to mark a document paid, or delete a payment to reverse it. - aid: quaderno:quaderno-transactions-api name: Quaderno Transactions API tags: - Transactions - Sales - Tax image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://developers.quaderno.io/api/ baseURL: https://ACCOUNT_NAME.quadernoapp.com/api properties: - url: https://developers.quaderno.io/api/ type: APIReference - url: openapi/quaderno-openapi.yml type: OpenAPI - url: collections/quaderno.postman_collection.json type: PostmanCollection - url: collections/quaderno.opencollection.json type: OpenCollection description: Record a sale and calculate its tax in a single call - the transactions endpoint determines tax from customer location evidence and item tax codes and creates the corresponding tax-compliant document. - aid: quaderno:quaderno-checkout-api name: Quaderno Checkout API tags: - Checkout - Payments - Hosted image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://developers.quaderno.io/guides/checkout/ baseURL: https://ACCOUNT_NAME.quadernoapp.com/api properties: - url: https://developers.quaderno.io/guides/checkout/ type: Documentation - url: https://developers.quaderno.io/api/ type: APIReference - url: openapi/quaderno-openapi.yml type: OpenAPI - url: collections/quaderno.postman_collection.json type: PostmanCollection - url: collections/quaderno.opencollection.json type: OpenCollection description: Create and retrieve hosted Checkout sessions that collect tax-compliant payments - rendered client-side with Quaderno.js or as a hosted page - and surface checkout.succeeded, checkout.failed, and checkout.abandoned events. - aid: quaderno:quaderno-webhooks-api name: Quaderno Webhooks API tags: - Webhooks - Events - Notifications image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://developers.quaderno.io/guides/webhooks/ baseURL: https://ACCOUNT_NAME.quadernoapp.com/api properties: - url: https://developers.quaderno.io/guides/webhooks/ type: Documentation - url: https://developers.quaderno.io/api/ type: APIReference - url: openapi/quaderno-openapi.yml type: OpenAPI - url: collections/quaderno.postman_collection.json type: PostmanCollection - url: collections/quaderno.opencollection.json type: OpenCollection description: Subscribe URLs to real-time event notifications delivered as JSON over HTTPS - create, list, retrieve, update, and delete webhooks for document and checkout events, with automatic hourly retries for up to 72 hours on failure. common: - type: DomainSecurity url: security/quaderno-domain-security.yml - type: Authentication url: authentication/quaderno-authentication.yml - type: GitHubOrganization url: https://github.com/quaderno - type: LinkedIn url: https://www.linkedin.com/company/quaderno - type: Website url: https://quaderno.io - type: Documentation url: https://developers.quaderno.io - type: Plans url: plans/quaderno-plans-pricing.yml - type: RateLimits url: rate-limits/quaderno-rate-limits.yml - type: FinOps url: finops/quaderno-finops.yml maintainers: - FN: Kin Lane email: kin@apievangelist.com