Posted by the APIs.io catalog. APIs.io does not own or sell this API; you get access from the provider, Nylas.
The Nylas Contacts API lets an application read, create, update and delete a grant's contacts and contact groups. It is one part of the Nylas v3 platform, which offers REST APIs for email, calendar, contacts, scheduling, meeting notetaking, authentication and administration across Google, Microsoft, Exchange, iCloud, Yahoo and any IMAP provider. Developers building apps that need to sync or manage address books across many inbox providers would be the natural users.
What is published for it: an OpenAPI description and an APIs.json file. The base URL is https://api.us.nylas.com and the reference docs are at developer.nylas.com. Nylas also lists official SDKs for Node.js, Python, Ruby and Kotlin/Java, a CLI and a hosted MCP server.
Catalog ratings: Kin Score 88 (exemplar band). Agent Readiness 56.6 (agent-native band), scored 2026-10-17.
Pricing: set by the provider. The provider's access model is listed as freemium with self-serve signup.
Condition: a live hosted API, listed in the APIs.io catalog. You call the provider's endpoint.
Catalog listing: https://apis.io/apis/nylas/nylas-contacts-api/ Provider: https://www.nylas.com/