# CTD API

Build relationship intelligence into your internal tools. CTD exposes everything — paths, warmth scores, reachable contacts, job changes, ghost emails — via a REST API.

## API Overview & Authentication
Authentication, API keys, and which tier you need. [Read more](/content/guide/article/api-overview/index.html)

## User API — Freemium (free+)
Contacts, company lookups, relationship paths, job changes, and ghost emails — available on any CTD plan. [Read more](/content/guide/article/api-user-freemium/index.html)

## User API — Team & Business
Warm path search, reachable people and companies, path stage management — available on Team and Business plans. [Read more](/content/guide/article/api-user-team/index.html)

## Workspace API
Admin-only integration API. Global paths, target accounts import, and custom columns — for system integrations, not individual use. [Read more](/content/guide/article/api-workspace/index.html)

## Building Your Relationship Intelligence Stack
If you're consolidating tools into an internal platform, CTD exposes everything. Here's how to think about the integration. [Read more](/content/guide/article/api-internal-tools/index.html)