canonical: https://jentic.com/apis/nylas.com/nylas # Nylas API The Nylas API v3 provides a unified communications surface across email, calendar, and contacts that abstracts away the differences between Google, Microsoft, and IMAP backends. The 55-endpoint API covers OAuth-style hosted authentication, grant management, connector configuration, and full read/write operations on messages, threads, drafts, events, calendars, and contacts. It is well suited to building scheduling tools, inbox-aware AI assistants, and CRM enrichment workflows that need to read and write across whichever email and calendar provider the end user happens to use. ## For AI agents Read and write across users' email, calendars, and contacts on Google, Microsoft, and IMAP from a single unified API with bearer authentication and hosted auth. ## Scope Does not handle SMS, voice, push notifications, or marketing-grade email analytics - use for unified email, calendar, and contacts only. ## Capabilities - Run a hosted OAuth-style flow that returns a long-lived grant for a user's mailbox - Send, list, and reply to email messages and manage drafts on the user's behalf - Create, update, and delete calendar events with attendee and recurrence handling - List the user's calendars and read free/busy availability for scheduling agents - Manage contact records, including create, update, and delete operations - Configure connectors that map a Nylas application to Google, Microsoft, or IMAP backends ## Use cases ### AI Scheduling Assistant Build a meeting-scheduling assistant that reads a user's calendar, proposes free slots, and creates events with the right attendees, regardless of whether the user is on Google or Microsoft. The unified events and grants endpoints mean one code path covers both backends, and the hosted auth flow handles consent. A working scheduling integration is achievable in 1-2 days from a fresh Nylas account. Example prompt: GET /v3/grants/{grantId}/calendars/free-busy for the next five days, pick a 30-minute slot, then POST /v3/grants/{grantId}/events with the chosen time and attendees. ### Inbox-Aware AI Assistant Create an inbox copilot that summarises long threads, drafts replies, and triages on the user's behalf. Nylas exposes messages, threads, and drafts through a consistent shape, so an LLM-backed assistant can read context and write replies through the same interface across providers. This avoids maintaining separate Gmail and Microsoft Graph integrations. Example prompt: List the user's unread messages via /v3/grants/{grantId}/messages, summarise the top thread, and create a draft reply via POST /v3/grants/{grantId}/drafts. ### CRM Contact Enrichment Sync a user's contacts and recent email correspondents into a CRM to keep records up to date without manual entry. Nylas's contact endpoints, combined with thread participants from the messages API, provide a richer signal than a contacts-only sync. This is a common pattern for sales-engagement tools and lightweight CRMs. Example prompt: List contacts via /v3/grants/{grantId}/contacts and upsert each into the CRM, deduplicating on email address. ### Agent-Driven Communication Across Providers Let an AI agent send a message or schedule a meeting for a user without caring whether the underlying account is Google or Microsoft. Through Jentic, the agent searches by intent and gets only the operations it needs, with grant tokens held in the platform's vault rather than in the agent's context. Example prompt: Search Jentic for 'send an email from a user mailbox', load the operation, and send a follow-up email referencing yesterday's meeting. ## Key endpoints | Method | Path | Description | | --- | --- | --- | | POST | /v3/connect/auth | Start the hosted OAuth flow | | POST | /v3/connect/token | Exchange the auth code for a grant token | | GET | /v3/grants | List grants in a Nylas application | | DELETE | /v3/grants/{grantId} | Revoke a grant | | POST | /v3/connectors | Create a connector for a backend provider | ## Key resources - **Auth and Grants** — Hosted OAuth flow, grant lifecycle, and token management. - **Connectors** — Provider-level configuration linking a Nylas app to Google, Microsoft, or IMAP. - **Messages, Threads, Drafts** — Email read and write across providers. - **Events and Calendars** — Calendar list, free/busy, and full event lifecycle. - **Contacts** — Per-user contact records with create, update, and delete. ## Why Jentic - **Setup:** Wiring Nylas by hand means setting up its bearer token auth, choosing the right US or EU host, and managing per-user grant tokens yourself. Through Jentic you install once, import Nylas from the API Directory, store the API key once, and your agent calls it. - **Permission scoping:** Nylas puts the grant id in the URL path (/v3/grants/{grantId}), so a rule can pin your agent to the operations it needs on those grants: it can authenticate connections and read grants while a destructive operation like grant deletion is not included unless you add it. You choose the operations it may call. - **Credential handling:** Your Nylas API key and per-user grant tokens are stored once, encrypted, by your own Jentic One instance and injected at execution time. They never enter the agent's prompt, logs, or context. - **Discovery method:** Agents search Jentic by intent such as 'send an email from a user mailbox' or 'create a calendar event', and Jentic returns the matching Nylas operation with its input schema so the agent calls the right endpoint without browsing the reference docs. ## Related APIs - **Gmail API** — Direct provider API for Gmail-only workloads, without the unified abstraction. - **SendGrid Email Activity API** — Pair with Nylas for transactional email tracking and analytics on outbound messages. - **Twilio API** — Add SMS and voice channels alongside Nylas's email and calendar surface. ## FAQ ### What authentication does the Nylas API use? Nylas uses bearer authentication. Application-level calls send your Nylas API key in the Authorization header; per-user calls send the grant token issued by the hosted auth flow at /v3/connect/auth and /v3/connect/token. Through Jentic, both keys and grant tokens are stored encrypted in the vault. ### Does Nylas support Microsoft and Google in one API? Yes - that is the core value. The same /v3/grants/{grantId}/messages, /events, and /contacts paths work across Google Workspace, Microsoft 365, and IMAP backends, with the difference handled by Nylas's connector layer. ### What are the rate limits for the Nylas API? The OpenAPI spec does not embed explicit limits. Nylas applies per-application and per-grant throttling that varies by plan; back off on HTTP 429 and the X-RateLimit-* response headers when present. ### How do I send an email from a user's mailbox through Jentic? Run pip install jentic, then search for 'send an email from a user mailbox'. Jentic returns the messages-send operation with its input schema; supply the grant id, recipients, subject, and body and execute. Run it through Jentic One, the self-hosted execution layer, to get an agent API key. ### Can I find a free time slot for a user? Yes - the free/busy endpoints expose availability for the user's connected calendars across providers, so an agent can pick a slot before posting an event via POST /v3/grants/{grantId}/events. ### Can I limit what my agent is allowed to do with the Nylas API? Yes. Because you run Jentic One yourself, your own rules decide which Nylas operations and which credentials the agent may use at execution time. Since Nylas puts the grant id in the URL path (/v3/grants/{grantId}), you can pin the agent to just the operations it needs, for example authenticating connections and reading grants, messages, and events, while a destructive call like grant deletion stays out of reach unless you explicitly add it. You choose the exact set of operations the agent can call.