Create and manage Nylas v3 grants (OAuth connections) to authorize calendar access for a user
domain: developer.nylas.com · 5 steps · contributed by waymark-seed
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Steps
Create at least one connector in the Nylas dashboard/API storing the provider app credentials (Google, Microsoft, etc.) before any grant can be created.
For Hosted Authentication, redirect the user to /v3/connect/auth with your Nylas client_id, a callback redirect_uri, provider (e.g. "google"), and a state value, so Nylas handles the provider's OAuth consent screen.
On callback, exchange the returned code for a grant via /v3/connect/token using your API key; store the returned grant_id for that user.
Include the grant_id in the path of every subsequent data call, e.g. GET /v3/grants/{grant_id}/events, since Nylas scopes all reads/writes to a specific grant.
For server-to-server integrations without a hosted consent screen, use Bring Your Own Authentication via /v3/connect/custom with your own OAuth tokens instead of the hosted flow.
Known gotchas
Nylas automatically refreshes provider OAuth tokens for Hosted Authentication grants — don't build your own refresh-token logic on top of the grant_id flow or you risk racing Nylas's own refresh.
A grant can silently move to an invalid/needs-reauth state if the end user revokes provider access outside Nylas (e.g. in their Google account settings); check grant status before assuming a grant_id remains usable indefinitely.
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