generated: '2026-07-21'
method: searched
source: https://developers.lessen.com/docs/
versioning:
  scheme: path-namespace
  current: v2 (GraphQL)
  docs: https://developers.lessen.com/docs/#/client/overview
  notes: >-
    One Open API v1 was REST; v2 is a complete GraphQL rewrite. Client and Vendor
    surfaces are namespaced under /one-graph-client and /one-graph-vendor.
deprecation:
  policy: additive-backward-compatible
  docs: https://developers.lessen.com/docs/#/client/guides/webhook/about-webhooks
  description: >-
    Documented backward-compatibility policy: existing fields are not removed or
    retyped without prior notice and a deprecation period; changes are additive
    only; consumers must ignore unknown fields (forward compatibility). Webhook
    event schemas follow the same additive-only contract.
  sunsets:
  - api: Affiliate Open API v1.0
    sunset_date: '2025-12'
    status: retired
    note: Sunset in December 2025; no longer available.
  - api: One Open API v1 (REST)
    status: superseded
    note: Rewritten as the v2 GraphQL API.
  data_retention:
  - Invoice query API is limited to work orders created within the last 2 years
    (effective 2026-05-12).
sla:
  status_page: https://status.lessen.com/
status_page: https://status.lessen.com/
pricing_notice: >-
  A usage-based pricing/metering model for the Vendor Open API and webhook usage
  is under development (announced 2026); scope, metering, rates, and effective
  date to be published to vendor API users before billing takes effect.
deprecated_operations: []