Posted by the APIs.io catalog. APIs.io does not own or sell this API; you get access from the provider, Stannp.
The Stannp Campaigns API lets software manage batch direct mail campaigns. Stannp is a direct mail platform that sends physical postcards and letters programmatically. Through its REST API, developers can create campaigns, upload recipient lists, trigger individual mail pieces in real time, and track print and delivery status through webhooks and event endpoints. Authentication uses an API key with HTTP Basic Auth over HTTPS, and responses follow a simple JSON envelope with success/data or success/error fields. Base URL: https://api-us1.stannp.com/v1.
Who it suits: businesses and developers in the UK, US and Canada who want to add physical mail to marketing automation, fulfillment or customer-communication workflows. The provider also lists no-code integrations through Zapier and Make, and official SDKs for PHP, Go and C#.
Published for this API: OpenAPI, Overlay, AgentSkill, Documentation, JSONSchema, Vocabulary and JSONLDContext artifacts.
Catalog scores: the provider has a Kin Score of 74.2 (exemplar band) and an Agent Readiness score of 43 (agent-native band, scored 2026-11-06).
Pricing: set by the provider
Condition: a live hosted API you call at the provider's endpoint, listed in the APIs.io catalog. Access is paid and not public.
Catalog listing: https://apis.io/apis/stannp/stannp-campaigns-api/ Provider: https://www.stannp.com