You picked a unified API so you wouldn’t have to babysit Gmail’s Pub/Sub topics, Microsoft Graph’s expiring subscriptions, and a fleet of IMAP connections. Aurinko is one option in that category, and it’s a reasonable one. But if you’re weighing it against Nylas, the questions that actually matter are how each handles email and calendar sync, whether the response schema stays the same across providers, and whether you get real-time webhooks or end up polling anyway.
This guide compares Aurinko with the Nylas approach to email and calendar sync, shows the exact endpoints you’d call, and is honest about the cases where you wouldn’t switch.
Aurinko vs a unified Nylas sync layer
Section titled “Aurinko vs a unified Nylas sync layer”Both Aurinko and Nylas sit in front of Gmail, Microsoft 365, and IMAP so you authenticate once and read mail through one API instead of three native clients. The practical difference shows up in the schema and the update model: with the unified API, every connected account becomes a grant, and GET /v3/grants/{grant_id}/messages returns the same id, subject, from, and folders fields whether the account is Gmail, Outlook, or generic IMAP.
The two products overlap on the core promise of one integration across many providers. Where they diverge is breadth and the update mechanism. The grant model covers 6 providers behind a single OAuth flow at /v3/connect/auth, and change notifications arrive through one webhook subscription created at /v3/webhooks rather than per-resource subscriptions you renew. The table compares the work each approach requires for a real sync pipeline.
| Task | Aurinko | Unified Nylas API |
|---|---|---|
| Auth model | Per-account OAuth across providers | 1 OAuth flow through /v3/connect/auth, 1 grant per account |
| Read mail | Unified messages endpoint | GET /v3/grants/{grant_id}/messages |
| Read calendar | Unified calendar endpoint | GET /v3/grants/{grant_id}/events?calendar_id= |
| Real-time updates | Webhooks where supported | One /v3/webhooks subscription, message.created/event.created |
| Schema | Normalized per provider | Same JSON for all 6 providers |
How do I add email sync to my SaaS without building IMAP infrastructure?
Section titled “How do I add email sync to my SaaS without building IMAP infrastructure?”Connect each account through a hosted OAuth flow, then read mail through one REST endpoint instead of running IMAP servers. You send users to /v3/connect/auth, get a grant_id per account, and call GET /v3/grants/{grant_id}/messages. There are no IDLE connections and no reconnect logic, and the same call works across all 6 supported providers.
Building IMAP yourself means long-lived connections per mailbox, a worker pool that scales with your user count, and handling provider quirks like Gmail’s labels-as-folders model. The grant abstraction removes all of it. Each connected account gets a stable grant_id, and OAuth token refresh happens server-side, so your sync loop never sees a 401 from an expired Google or Microsoft token. The request below lists the most recent 50 messages from one account; limit accepts up to 200 per page.
curl --request GET \ --url 'https://api.us.nylas.com/v3/grants/<NYLAS_GRANT_ID>/messages?limit=50' \ --header 'Accept: application/json' \ --header 'Authorization: Bearer <NYLAS_API_KEY>'from nylas import Client
nylas = Client(api_key="<NYLAS_API_KEY>")
messages = nylas.messages.list( "<NYLAS_GRANT_ID>", query_params={"limit": 50},)
for message in messages.data: print(message.subject, message.from_)For the full multi-account pipeline with backfill and incremental updates, see sync Gmail, Outlook, and Exchange email.
What should developers look for in a calendar sync API?
Section titled “What should developers look for in a calendar sync API?”Look for one schema across providers, real-time push instead of polling, and a Free/Busy primitive you don’t have to compute yourself. A strong calendar sync API returns Google and Microsoft events in an identical shape, pushes event.created and event.updated notifications through webhooks, and exposes availability directly. Nylas reads events through GET /v3/grants/{grant_id}/events with a required calendar_id query parameter.
The trap when building calendar sync yourself is recurrence and availability. Expanding a recurring series and reconciling cancelled instances across Google and Microsoft is fiddly, and computing who’s free across several mailboxes is worse. The events endpoint normalizes the when object and exposes expand_recurring so the API does the expansion, returning up to 200 events per page. For availability, post attendee email addresses to /v3/grants/{grant_id}/calendars/free-busy with start_time and end_time as Unix timestamps, and you get back busy blocks per account. The request below reads upcoming events from a connected calendar through GET /v3/grants/{grant_id}/events.
curl --request GET \ --url 'https://api.us.nylas.com/v3/grants/<NYLAS_GRANT_ID>/events?calendar_id=primary&limit=50' \ --header 'Accept: application/json' \ --header 'Authorization: Bearer <NYLAS_API_KEY>'events = nylas.events.list( "<NYLAS_GRANT_ID>", query_params={"calendar_id": "primary", "limit": 50},)
for event in events.data: print(event.title, event.when)Are there APIs for integrating with multiple email providers?
Section titled “Are there APIs for integrating with multiple email providers?”Yes. A unified API exposes one set of endpoints across many providers, so you write the integration once. Nylas covers Gmail, Microsoft 365, Yahoo, iCloud, generic IMAP, and Exchange (EWS) behind a single grant model. The same GET /v3/grants/{grant_id}/messages call reads any of the 6, and adding a new provider later costs zero new code in your sync engine.
The alternative is one integration per provider: a Google Cloud project plus the Gmail API, an Azure app registration plus Microsoft Graph, and a hand-rolled IMAP client for everything else. Each carries its own OAuth project, ID format, quota, and message schema. The unified layer collapses that into a single code path. To see which accounts your application can sync, call GET /v3/grants, which returns each connection’s id, provider, and grant_status. The request below pages through every grant 50 at a time so you can schedule backfills and confirm webhook coverage.
curl --request GET \ --url 'https://api.us.nylas.com/v3/grants?limit=50' \ --header 'Accept: application/json' \ --header 'Authorization: Bearer <NYLAS_API_KEY>'The same grant reaches both email and calendar, so a product that starts with inbox sync can add scheduling without a second integration.
Webhooks vs polling for staying in sync
Section titled “Webhooks vs polling for staying in sync”Use webhooks for real-time sync and reserve polling for backfill and reconciliation. After the initial import, register one subscription at /v3/webhooks for triggers like message.created, message.updated, and event.created, and the API pushes each change as a JSON payload. Webhooks remove the constant GET requests polling needs, which keeps you well under rate limits and cuts latency from minutes to seconds.
The mechanism matters because polling every mailbox on a fixed interval doesn’t scale: 1,000 accounts polled each minute is 1,000 wasted requests when nothing changed. A single webhook subscription replaces that traffic. One detail to plan for: webhook payloads cap at 1 MB, and a notification over that limit arrives truncated with a .truncated suffix, so on message.updated.truncated you re-fetch the message by ID. The webhooks vs polling guide covers the listener, retries, and when a periodic reconciliation poll still earns its place.
When is Aurinko or a native API the right call?
Section titled “When is Aurinko or a native API the right call?”Pick the tool that matches your provider mix and feature needs, not the brand. If your product targets a single provider and depends on services outside mail and calendar, calling that provider’s native API directly is the right move. Microsoft Graph reaches Teams, SharePoint, and OneDrive that no unified layer exposes, and the Gmail API gives you full control of one Google surface.
Aurinko is a fair choice too, and the honest comparison is about fit. If its provider coverage, regional hosting, and pricing line up with your roadmap, there’s no reason to migrate for its own sake. The case for switching is concrete: you need the same schema across 6 providers, one webhook model instead of per-resource subscriptions, and add-ons like Notetaker and Scheduler on the same grant. Aurinko’s limits and pricing can change, so compare its current docs against your projected volume before committing. For the build-vs-buy math against raw IMAP, see IMAP vs a unified email API.
What’s next
Section titled “What’s next”- Sync Gmail, Outlook, and Exchange email for the full backfill plus webhook pipeline
- Webhooks vs polling to design real-time sync that stays under rate limits
- IMAP vs a unified email API for the build-vs-buy tradeoff against raw IMAP
- Getting started with Nylas to create a project, connector, and your first grant