Quarterwise API: OpenAPI specification

The OpenAPI 3.1 description of the Quarterwise API, for generating clients, importing into Postman or Insomnia, or reading in any OpenAPI viewer.

The API lets you push property and self-employment income and expenses into your Quarterwise books from your own scripts, spreadsheets or systems, and read back what is recorded. It does not file anything with HMRC. Quarterly updates and the tax return are always reviewed and sent by the account holder in the app.

• Full guide: https://quarterwise.co.uk/developers/docs
• Live spec: https://quarterwise.co.uk/api/v1/openapi.json (always current; this repo is a copy)
• Examples: https://github.com/quarterwise/api-examples

At a glance

Base URL	https://quarterwise.co.uk/api/v1
Auth	Authorization: Bearer qw_live_..., a key from Account, then API access, in the app (Pro plan)
Format	JSON over HTTPS
Money	Whole pence as integers. £450.00 is 45000
Dates	YYYY-MM-DD
Rate limits	120 requests a minute per key, 5,000 transactions written per rolling 24 hours

Method	Path	What it does
GET	/me	Who the key belongs to and what it can do
GET	/sources	Your properties and self-employment businesses
GET	/categories	Valid category keys for each source type
GET	/sources/{id}/transactions	List entries, with date filters and cursor paging
POST	/sources/{id}/transactions	Add one entry or up to 500 at once

Set externalRef on every entry you post. Posting the same ref again returns the existing entry instead of creating a second one, so a retried import can't count income twice.

Entries posted without a category go to the review queue in the app for the account holder to sort.

Using the spec

Generate a TypeScript client:

npx @openapitools/openapi-generator-cli generate -i openapi.json -g typescript-fetch -o ./quarterwise-client

Or open openapi.json in Swagger Editor to browse it.

Keeping this copy current

./scripts/update.sh

downloads the live spec over openapi.json. If the two ever differ, the live one is right.

Support

support@quarterwise.co.uk

Licensed under MIT. Quarterwise is a trading name of Malden Ltd.