> ## Documentation Index
> Fetch the complete documentation index at: https://docs.inflection.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> A REST API for reading and writing the people in your Inflection workspace: their profiles, product and marketing activity, static lists, and emails.

The Inflection Developer API gives you programmatic access to the core objects of your workspace. It's organized around five resources:

* **Contacts**: look people up by id or email, create them, and keep their attributes in sync.
* **Contact activity**: a contact's product events, marketing engagement, a change log of record properties, and the mapped Salesforce record.
* **Lists & members**: static lists and the contacts on them.
* **Emails**: create HTML emails in Inflection, and fetch emails (both HTML and visual editor) by ID.
* **Email versions**: push per-contact versions of a [Personalized Email Asset](/agents/personalized-email) via `POST /v1/email-versions` for 1:1 sends at scale. See [Send Personalized Emails from Clay](/agents/send-personalized-emails-from-clay) for a worked example.

<Info>
  Every path lives under `/v1` on the API gateway: `https://api.inflection.io`
</Info>

The API is JSON over HTTPS, authenticated with a bearer token, either a Personal Access Token or an OAuth access token (see [Authentication](/api-reference/authentication)). Reads are synchronous; contact writes are processed asynchronously and return a transaction you poll (see [Asynchronous writes](/api-reference/async-writes)).

<CardGroup cols={2}>
  <Card title="Quickstart" icon="rocket" href="/api-reference/quickstart">
    From zero to your first response in two calls.
  </Card>

  <Card title="Authentication" icon="key" href="/api-reference/authentication">
    Tokens, scopes, and what 401 vs 403 mean.
  </Card>
</CardGroup>