Cal.com Public API (Enterprise Only)

This is the public REST api for cal.com. It exposes CRUD Endpoints of all our most important resources. And it makes it easy for anyone to integrate with Cal.com at the application programming level.

Stack

• NextJS
• TypeScript
• Prisma

Development

Setup

1. Clone the main repo (NOT THIS ONE)

   git clone --recurse-submodules -j8 https://github.com/calcom/cal.com.git
   

2. Go to the project folder

   cd cal.com
   

3. Copy apps/api/.env.example to apps/api/.env

   cp apps/api/.env.example apps/api/.env
   cp packages/prisma/.env.example packages/prisma/.env
   

4. Install packages with yarn

   yarn
   

5. Start developing

   yarn workspace @calcom/api dev
   

6. Open http://localhost:3002 with your browser to see the result.

API Authentication (API Keys)

The API requires a valid apiKey query param to be passed: You can generate them at https://app.cal.com/settings/security

For example:

GET https://api.cal.com/v1/users?apiKey={INSERT_YOUR_CAL.COM_API_KEY_HERE}

API Keys optionally may have expiry dates, if they are expired they won't work. If you create an apiKey without a userId relation, it won't work either for now as it relies on it to establish the current authenticated user.

In the future we might add support for header Bearer Auth if we need to or if our customers require it.

Middlewares

We don't use the new NextJS 12 Beta Middlewares, mainly because they run on the edge, and are not able to call prisma from api endpoints. We use instead a very nifty library called next-api-middleware that let's us use a similar approach building our own middlewares and applying them as we see fit.

• withMiddleware() requires some default middlewares (verifyApiKey, etc...)

Next.config.js

Redirects

Since this is an API only project, we don't want to have to type /api/ in all the routes, and so redirect all traffic to api, so a call to api.cal.com/v1 will resolve to api.cal.com/api/v1

Likewise, v1 is added as param query called version to final /api call so we don't duplicate endpoints in the future for versioning if needed.

Transpiling locally shared monorepo modules

We're calling several packages from monorepo, this need to be transpiled before building since are not available as regular npm packages. That's what withTM does.

  "@calcom/app-store",
  "@calcom/prisma",
  "@calcom/lib",
  "@calcom/ee",

API Endpoint Validation

We validate that only the supported methods are accepted at each endpoint, so in

• /endpoint: you can only [GET] (all) and [POST] (create new)
• /endpoint/id: you can read create and edit [GET, PATCH, DELETE]

Zod Validations

The API uses zod library like our main web repo. It validates that either GET query parameters or POST body content's are valid and up to our spec. It gives errors when parsing result's with schemas and failing validation.

We use it in several ways, but mainly, we first import the auto-generated schema from @calcom/prisma for each model, which lives in lib/validations/

We have some shared validations which several resources require, like baseApiParams which parses apiKey in all requests, or querIdAsString or TransformParseInt which deal with the id's coming from req.query.

• [*]BaseBodyParams that omits any values from the model that are too sensitive or we don't want to pick when creating a new resource like id, userId, etc.. (those are gotten from context or elswhere)

• [*]Public that also omits any values that we don't want to expose when returning the model as a response, which we parse against before returning all resources.

• [*]BodyParams which merges both [*]BaseBodyParams.merge([*]RequiredParams);

• withValid[*] which is currently not being much used because is only useful in only post endpoints (we do post/get all in same file). This would validate the req.body of a POST call to API against our BaseBodyParams validation

Next Validations

Next-Validations Docs Next-Validations Repo We also use this useful helper library that let us wrap our endpoints in a validate HOC that checks the req against our validation schema built out with zod for either query and / or body's requests.

Testing with Jest + node-mocks-http

We aim to provide a fully tested API for our peace of mind, this is accomplished by using jest + node-mocks-http

Endpoints matrix

resource	get [id]	get all	create	edit	delete
attendees	✅	✅	✅	✅	✅
availabilities	✅	✅	✅	✅	✅
booking-references	✅	✅	✅	✅	✅
event-references	✅	✅	✅	✅	✅
destination-calendars	✅	✅	✅	✅	✅
custom-inputs	✅	✅	✅	✅	✅
event-types	✅	✅	✅	✅	✅
memberships	✅	✅	✅	✅	✅
payments	✅	✅	❌	❌	❌
schedules	✅	✅	✅	✅	✅
selected-calendars	✅	✅	✅	✅	✅
teams	✅	✅	✅	✅	✅
users	✅	👤[1]	✅	✅	✅

Models from database that are not exposed

mostly because they're deemed too sensitive can be revisited if needed. Also they are expected to be used via cal's webapp.

• Api Keys
• Credentials
• Webhooks
• ResetPasswordRequest
• VerificationToken
• ReminderMail

Documentation (OpenAPI)

You will see that each endpoint has a comment at the top with the annotation @swagger with the documentation of the endpoint, please update it if you change the code! This is what auto-generates the OpenAPI spec by collecting the YAML in each endpoint and parsing it in /docs alongside the json-schema (auto-generated from prisma package, not added to code but manually for now, need to fix later)

@calcom/apps/swagger

The documentation of the API lives inside the code, and it's auto-generated, the only endpoints that return without a valid apiKey are the homepage, with a JSON message redirecting you to the docs. and the /docs endpoint, which returns the OpenAPI 3.0 JSON Spec. Which SwaggerUi then consumes and generates the docs on.

Deployment

scripts/vercel-deploy.sh The API is deployed to vercel.com, it uses a similar deployment script to website or webapp, and requires transpilation of several shared packages that are part of our turborepo ["app-store", "prisma", "lib", "ee"] in order to build and deploy properly.

Envirorment variables

Required

DATABASE_URL=DATABASE_URL="postgresql://postgres:@localhost:5450/calendso"

Optional

APIKEY_PREFIX=cal# This can be changed per envirorment so caltest for staging for example.

If you're self-hosting under our commercial license, you can use any prefix you want for api keys. either leave the default cal_ (not providing any envirorment variable) or modify it