Pyas vs. Unipile: messaging and email API vs. calendar API

The core difference

Unipile describes itself as "the Unified API to interact with messaging, mailing, calendar and social services" (Unipile docs). Your users link LinkedIn, WhatsApp, Instagram or Telegram, Gmail, Outlook or IMAP mailboxes, and Google or Outlook calendars, and your code talks to all of them through one API. Calendars are one channel among several, and the pricing treats them that way: every linked account is billed at the same rate whatever the channel.

Pyas is a calendar API. It connects Google Calendar, Microsoft 365 and Outlook.com, plus Zoom for meeting links, and nothing else. No email, no messaging, no contacts. What it does add is the layer a calendar product needs on top of reading and writing events: free/busy across accounts, a search for times when everyone is free, Zoom meetings created on any calendar, a sandbox with sample calendars, and prices set for calendar accounts.

So the decision mostly comes down to what else your product touches. A sales or recruiting tool that reads LinkedIn messages and inboxes and also books the occasional meeting is what Unipile is built for. A product where the calendar is the point gets more depth from Pyas, at a lower price per account.

When Unipile is the right choice

• Your product needs messaging or email. Outreach tools, recruiting CRMs and unified inboxes need LinkedIn, WhatsApp or Gmail access.
• You want one vendor for every channel a user links. One linking flow, one API, one bill, with calendars included.
• You want a Python SDK today. Unipile has Node.js and Python SDKs. Pyas has TypeScript today, with Python, PHP, Ruby and Go SDKs planned.
• You need RSVP, cancel and restore, or shared calendars. Unipile documents all three as calendar features.

When Pyas is the right choice

• You are building scheduling, booking or availability. Pyas returns free/busy for up to 20 accounts, and the first times everyone is free inside working hours, with buffers, minimum notice, optional attendees and rooms, across Google and Outlook in one call.
• You need Zoom links on any calendar. Pyas creates the Zoom meeting through the host's connected Zoom account and puts it on a Google or Outlook event.
• You expect hundreds or thousands of accounts. At 1,000 accounts the list prices are $4,500 a month on Unipile and $275 on Pyas.
• You want to build before anyone connects a real calendar. Every Pyas app has a sandbox with simulated Google, Outlook and Zoom accounts.
• You want the connect step inside your own page. PyasConnect is a dialog for React, Vue, Angular or plain HTML. Unipile offers a hosted auth page.
• You are giving calendars to an AI agent and want a hosted MCP server, or a local one with a read-only mode.

Who handles Google's review

Neither product makes you go through it. Unipile's docs say "By default, your integration uses Unipile's OAuth credentials" for Google and for Microsoft, with your own apps as an option. Unipile also says on its blog that its Google OAuth client is CASA Tier 2 certified, which matters if you need Gmail.

Pyas works the same way. With Pyas Auth, on every plan including the free one, users approve Pyas on Google's, Microsoft's and Zoom's own consent screens, and Google, Microsoft and Zoom have already verified it. If you want your own name on the consent screen, Native Auth lets you use your own Google or Microsoft app instead, per provider.

Why this matters: Google classes calendar scopes as sensitive. Before an app is verified it is limited to test users or shows an unverified-app warning, and the review asks for verified domains, a privacy policy, scope justifications and a demo video. Our guide to Google's OAuth review covers how long it takes.

Microsoft is different. A Microsoft 365 organization's consent policy can require an administrator to approve calendar access, whichever app users are approving. That is true with Unipile's credentials, with Pyas Auth, and with your own app. See why Outlook says it needs admin approval.

What Unipile does well

Breadth. One API covers LinkedIn, WhatsApp, Instagram, Telegram, three kinds of email and two calendar providers. For a product that needs several of these, that saves integrating each one.

Published, simple pricing. One rate per linked account, falling with volume, listed on the pricing page in USD and EUR. No sales call to find out what it costs.

Sign-in done for you. Default Google and Microsoft credentials, plus a CASA Tier 2 assessment on the Google client according to its blog, so even Gmail access does not start with Google's review.

Webhooks with the event in them. Unipile's calendar webhooks carry the full event on create and update, so you can act without a follow-up read. Deletes carry IDs.

Calendar extras. RSVP to invitations, cancel and restore events, and shared calendars are documented features.

Two SDKs and a hosted MCP server. Node.js and Python, and a hosted MCP server for AI agents.

Where Pyas is different

Finding free time. Unipile's API reference has no free/busy or availability endpoint. With Unipile you would pull each person's events and compute the gaps yourself, across time zones and providers. Pyas answers that in one call, for up to 20 accounts, and can return meeting times that respect working hours, buffers and minimum notice.

Meeting links. Pyas uses one field, conferencing: Google Meet on Google, Teams on Microsoft 365 work accounts, and Zoom on any calendar, where Pyas creates the Zoom meeting itself. On Outlook.com personal accounts a Teams request is refused with a clear error. Unipile's docs disagree with themselves here. The API reference says that if conference.url is not provided, "it will automatically create a new conference (only teams and google_meet available)", while the v2 guide says "Unipile does not support the generation of conferences so you must create the meeting on the provider". For Zoom, you attach a link you already have. Our meeting links guide explains what each provider allows.

Webhooks that name the change. A Pyas webhook carries the IDs of the event or calendar that changed, and your app reads it. That is one more request than Unipile's create and update payloads, and it means Pyas does not store copies of your users' events. Webhooks are signed, retried up to 8 attempts and replayable, and Pyas keeps Google push channels and Microsoft Graph subscriptions renewed. More in our webhooks guide.

Account health. Each connected account reports its status, why it broke and how to fix it. A connection.broken webhook tells you, and the user reconnects inside your app with PyasConnect, keeping the same accountId.

Event details. Every event comes back in one shape from Google and Outlook, with UTC plus local time and the IANA time zone. Writes take idempotency keys, and updates can carry If-Match so a stale write is refused instead of overwriting someone else's change.

Testing. Unipile's test mode uses real accounts, and its docs describe no sandbox or sample data. Pyas test keys reach a sandbox of simulated Google, Outlook and Zoom accounts with sample people and real-looking calendars, and the CLI streams sandbox webhooks to your laptop.

AI agents. Unipile's MCP server is hosted and makes live API calls, and its docs describe no read-only mode. Pyas has a hosted server at mcp.pyas.io, the same server as @pyas/mcp to run locally with a read-only mode, and @pyas/ai-tools for the Vercel AI SDK, LangChain, OpenAI and Anthropic tool use. See calendars for AI agents.

Can you use both?

For the same users and the same calendars, rarely. Each user would link the same Google or Microsoft account twice, you would pay for it twice and handle two sets of webhooks.

It can make sense when the jobs are split. A recruiting tool might use Unipile for LinkedIn and WhatsApp messages and Pyas for interview scheduling, with users linking LinkedIn through Unipile and their calendar through PyasConnect. Unipile bills every linked account, so if you already link Gmail or Outlook mail through it, ask Unipile how it counts that user's calendar before you plan on any saving.

Questions to ask before you choose

• Does the product need email or messaging, now or within a year? If yes, Unipile covers it.
• How many accounts will be connected in 12 months? Run both through the price table above. At 200 accounts the gap is $1,000 against $75 a month.
• Do you need to find a time that works for several people? Pyas has free/busy and meeting times. Unipile's API reference has no availability endpoint.
• Which meeting links must you create? If it is Zoom, only Pyas creates the meeting. For Teams and Meet on Unipile, test it, since its docs disagree.
• Do your users have personal Outlook.com accounts? Pyas supports them. Unipile's docs say "Google and Outlook calendars" without saying whether personal accounts are included, so ask.
• What language is your backend in? Unipile has a Python SDK today. Pyas has TypeScript, with Python, PHP, Ruby and Go SDKs planned; any language can call its REST API meanwhile.
• Do you want webhooks to carry the event, or name it? Unipile sends the event on create and update. Pyas sends IDs and keeps no copy of your users' events.

Moving from Unipile to Pyas

1. Build against the sandbox first. Point your calendar code at Pyas with test keys and work through reads, writes, recurring events and meeting links against sample calendars. No real account is touched.
2. Map the calls. Replace Unipile's calendar endpoints with Pyas's. Swap attached Zoom URLs for the conferencing field so Pyas creates the meeting. If you computed free time from event lists, replace that with the free/busy or meeting-times call.
3. Map the webhooks. Unipile's create and update webhooks carried the full event. With Pyas, take the event ID from the webhook and read the event. Deletes map one to one. Add a handler for connection.broken.
4. Have users reconnect once. Each user links their calendar again through PyasConnect. Their events stay where they are, in Google and Outlook, so there is nothing to export or import.
5. Ask Unipile how calendar links are counted. If you keep Unipile for messaging or email, check whether unlinking a user's calendar changes its per-account count before you count on a saving.

Looking for a Unipile alternative?

Start with what you use Unipile for. If it is mostly calendars, a calendar API covers more of that job than a messaging one.

If calendars are all you use Unipile for

This is the clearest case for Pyas. You keep Google, Outlook and Zoom coverage, gain free/busy, meeting times and a sandbox, and pay calendar prices. See how Pyas works and the use cases it is built for.

If cost per account is the problem

Unipile's lowest per-account rate is $3.50, and only past 5,000 accounts. Pyas's Scale plan is $75 for 200 accounts, then $0.25 each, so 3,000 accounts cost $775 a month. See pricing.

If you are building scheduling or booking

You need availability across people and providers. That is the free/busy and meeting-times work in Pyas. Pyas does not supply booking pages or round robin, so you build that UI on top.

If you need Zoom links on Google or Outlook events

Pyas creates the Zoom meeting through the host's connected Zoom account and adds it to the event, on either provider.

Other options

• Nylas
• Cronofy
• Apiroc
• Aurinko
• Building it yourself on the official Google Calendar API and Microsoft Graph. You get full control and take on Google's OAuth review, Microsoft app registration, push channel and subscription renewal, and two event models.

The bottom line

Unipile and Pyas overlap on Google and Outlook calendars, and both spare you Google's OAuth review. Past that they are built for different products. Unipile is built for products where calendars sit next to LinkedIn, WhatsApp and email. Pyas is built for products where the calendar is the point: finding free time, creating Meet, Teams and Zoom links, testing against a sandbox, and paying $75 instead of $1,000 a month at 200 accounts.