# Integrations — EternalEngine

EternalEngine ships with built-in payments, email, an iCal calendar feed, SSO and a REST API. QuickBooks, Slack and Zapier connections are on the roadmap.

Integrations

# Connect to what you already use

Most "integrations" you'd pay extra for elsewhere ship as built-in apps in EternalEngine — payments, email, storage, identity. The ones that don't yet are listed below, honestly marked as roadmap.

[Start free](https://app.eternalengineos.io/signup?plan=free&interval=annual)[See every built-in app](https://eternalengineos.io/features/)

Built In Today

## Native — no integration needed

These ship as part of EternalEngine. No third-party account, no separate billing, no glue code.

### Payment Processing

[PayGate](https://eternalengineos.io/features/paygate/) ships on every paid plan with a Free tier (3.4% + $0.30 all-in per card transaction) and optional paid tiers ($49 Growth, $149 Scale) for lower fees and higher volume caps. Hosted checkout, subscriptions, payouts, dispute tracking — all in-app, no third-party connect required.

Built-inEvery paid tier

### Email Delivery

[PostFrame](https://eternalengineos.io/features/postframe/) handles transactional + marketing email with SPF/DKIM/DMARC, opens, clicks, templates, webhooks. Optionally bring your own SES, SendGrid, Mailgun, or Postmark.

Built-inEvery paid tier

### Google + Outlook Calendar feed

[BookSlot](https://eternalengineos.io/features/bookslot/) publishes a subscribable iCal (.ics) feed of your appointments that Google Calendar, Outlook and Apple Calendar read, so every booking lands on the calendar your team already opens. Two-way sync is on the roadmap below.

Built-inEvery paid tier

### Cloud File Storage

[AssetVault](https://eternalengineos.io/features/assetvault/) is real S3-compatible cloud storage with folders, version history, tagging, multipart uploads, and tenant-isolated access. No external GDrive or Dropbox required.

Built-inPro & Business

### REST API & Webhooks

Every app exposes a versioned REST API with schema-validated inputs, structured logging, and tenant-scoped access. Webhooks fire on key events such as a paid invoice, a booked appointment or an accepted estimate — the way to connect a system we don't list.

Built-inEvery paid tier

### SSO — SAML 2.0 / OIDC

Sign in through your identity provider — Okta, Microsoft Entra ID (Azure AD), Google Workspace, Auth0, JumpCloud, or any SAML 2.0 / OIDC provider. Sessions, roles and permissions stay enforced in EternalEngine; SCIM provisioning is on the roadmap.

Built-inBusiness tier

On The Roadmap

## Native connections coming next

In active development. Visible in the in-app store with full marketing copy from day one — install opens as each ships.

QuickBooks & Xero

Two-way sync invoices, expenses, and chart-of-accounts data with [TitanLedger](https://eternalengineos.io/features/titanledger/).

Zapier & Make

5,000+ third-party apps via Zapier and Make. EternalEngine triggers + actions across the whole catalog.

Slack & Microsoft Teams

Surface deal events, invoice payments, project milestones, and AI alerts to your team channels.

S3 / GDrive / Dropbox mirror

Mirror AssetVault folders to your existing cloud storage so your team can access files from familiar tools.

Twilio (SMS)

SMS campaigns and notifications via TextCast — bring your own Twilio account or use bundled credits.

Salesforce / HubSpot

Migration helpers + ongoing sync for teams running ClientForge alongside legacy CRMs during the cut-over.

Google Workspace / Microsoft 365

Two-way calendar sync for [BookSlot](https://eternalengineos.io/features/bookslot/), Drive sync, Gmail/Outlook send-as, Workspace contact sync, and SCIM user provisioning.

Stripe Tax + Avalara

Automated sales tax calculation in TitanLedger invoices for multi-state and multi-country billing.

Want one we don't list?

[Tell us](https://eternalengineos.io/contact/) what you need. Most-requested integrations get prioritized.

## REST API + webhooks ship today

Build any connection you need with our versioned REST API and webhook firehose. Or talk to us about a custom integration — most-requested ones get added to the roadmap.

[Start free](https://app.eternalengineos.io/signup?plan=free&interval=annual)[Talk to sales](https://eternalengineos.io/contact/)