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Cal.com on Google Cloud Run

Cal.com on Google Cloud Run

Cal.com is an open-source, AGPL-licensed scheduling platform — the self-hosted Calendly alternative — built with Next.js and Prisma on PostgreSQL. This module deploys Cal.com on Cloud Run v2 on top of the App_CloudRun foundation, which provisions and manages the shared Google Cloud infrastructure.

This guide focuses on the cloud services Cal.com uses and how to explore and operate them from the Google Cloud Console and the command line. For the mechanics common to every Cloud Run application — service identity, ingress and load balancing, scaling and concurrency, CI/CD, Cloud Armor, IAP, Binary Authorization, VPC Service Controls, backups, and the deployment lifecycle — refer to the App_CloudRun foundation guide rather than repeating them here.


What Cal.com costs on RAD, and how that compares​

Cal.com on RAD's Cloud Run module costs about US$84 a month in your own Google Cloud project, with no extra licence fee — Cal.com is open source. In a project RAD manages for you, the same deployment is metered at 32 credits a day (about 960 a month, about US$96 at the top-up price). Or see the GKE guide for always-on capacity across pods. If you only need Cal.com occasionally — studying, a demo, a short-lived project — a RAD-managed project can be deleted and restored within 30 days for a few credits, so that monthly figure becomes a few dollars instead. See Pause it for free, below.

What you pay on RAD​

Cal.com is open source, so there is no licence fee. You pay for three things:

In a Google Cloud project you ownIn a project RAD manages for you
Module fee, once per deployment75 credits (US$7.50 at the top-up price)67.5 credits (10% lower)
Build timeA few credits per build (roughly 3–6 credits)The same
Google Cloud running costBilled by Google to your own billing account, about US$84 a month for the default configuration (table below)Metered hourly in credits; RAD publishes 32 credits a day, about 960 a month (about US$96 at the top-up price)
Who owns whatYou own the project and its billing; RAD deploys and updates itRAD owns the project, with guardrails, quotas and budget alerts; you get console access, and a minimum purchased balance is held in reserve

10 credits cost US$1 on a one-off top-up, and less on a monthly plan. In a project RAD manages, the database, file server and network are shared by every application in the project, so a second application does not add a second database.

Default running cost in your own project (us-central1, Google list prices):

Resource (module default)Per month
Cloud Run, 1x vCPU / 2 GiB (scaleToZero)US$13.16
Cloud SQL for PostgreSQL, 1 vCPU / 3.75 GB, zonal, 10 GB SSDUS$51.02
NFS/cache file server (small VM)US$13.43
Cloud NAT and networkingUS$5
Cloud Storage (add-ons, backups)US$1
Totalabout US$84

Cloud SQL and Cloud Run/GKE pod pricing is the same in africa-south1 (Johannesburg); the small VM costs about 10% more there.

  • Scale-to-zero is the default on Cloud Run. The figure above assumes modest daily use; set min_instance_count ≥ 1 to keep it always warm (and avoid cold starts), which raises the Cloud Run line but not the rest of the table.

How it compares, for a team of ten​

Cal.com, the project this module deploys, sells its own hosted plans per user:

OptionPer month (10 users)Notes
Cal.com TeamsUS$120 (US$12/user)Hosted by Cal.com
Cal.com OrganizationsUS$280 (US$28/user)Hosted by Cal.com, adds org-wide admin
RAD, Cloud Run, your own projectAbout US$84, plus US$7.50 once per deploymentRAD's automation, in your project
RAD, Cloud Run, a RAD-managed projectAbout 960 credits (US$96)RAD
  • Cal.com's hosted price grows with every seat; RAD's cost is the infrastructure, which a growing team only reaches the edge of when it needs more capacity. At ten users RAD's own-project running cost is already below a single month of the Teams plan.
  • A cheap server is cheap until something breaks. On RAD the database is Cloud SQL with automated backups, and secrets live in Secret Manager. On your own server, that is a job someone has to do.

Pause it for free: delete a RAD-managed project, restore it when you need it​

If Cal.com runs in a project RAD manages for you, deleting the whole project — rather than deleting just this module — unlinks its billing first, then asks Google to delete the project outright. Google keeps it, recoverable, for 30 days, and because billing is already unlinked, nothing is charged while it waits. Unlike deleting one module, this does not tear down Cloud SQL, any VM or the compute resource one by one: the whole project simply stops.

  • Restoring is a check, not a rebuild. Within 30 days, the project's owner can ask Google to undelete the project and reattach its billing account, then run Update on each deployment to confirm everything came back. Because nothing was individually destroyed, that Update finds the same resources already there, and an Update never charges the module fee again. For a typical 2–3-deployment chain this costs only a handful of credits in total (roughly 5–10 credits, under US$1).
  • What this needs. You must own the project (not one RAD only manages billing for), restore it yourself within 30 days — after that Google deletes it for good — and clear the tier's admission floor again (100 credits for the sandbox tier most study/demo use fits). Google says most services are fully working again within 36 hours of a restore.
  • One real gap: nightly backups do not survive. Backups are written to a bucket inside the project, and that bucket has Cloud Storage's soft-delete turned off, so it is very likely gone as soon as the project is deleted — even though the project itself is recoverable for 30 days. Copy a backup out (to Google Drive, or a bucket outside the project) before deleting if there is anything in it worth keeping; for a default install with nothing irreplaceable, this does not matter.

Source: Delete and restore projects.

Pay only while you use it, the other way: delete and redeploy​

In your own project, or once the 30-day restore window above has passed, the way to stop paying is to delete the deployment and deploy it again when you need it.

  • What a redeploy costs. The module fee again, plus the builds: about 79 credits (about US$7.90) at the top-up price, and roughly 15–20 minutes of build time (RAD's own platform average). Deleting saves money only once Cal.com would otherwise sit unused for about 3 days or more — in your own project that is about US$2.79 a day, and in a RAD-managed one it is 32 credits a day.
  • Most of the running cost here is usually the database and/or the shared file/cache VM or cluster. They stop only when nothing else in the project uses them, so deleting Cal.com while another application shares the project saves only Cal.com's own compute part.
  • Keep data first. Nightly backups go to a bucket inside the deployment and are deleted with it, so copy the latest backup out before deleting if you want to keep it.

Lab sessions and Managed Environments​

  • Lab sessions, for training. A trainer runs a session for a class. Each participant gets the app in their own Google Cloud project for 15 minutes to 24 hours, within an allowance the trainer sets. Either the trainer funds every place, or each participant pays for their own. Everything is deleted when the session ends and unused credits go back to the trainer.
  • Managed Environments, for consultancies. A partner runs the app for a client from a ring-fenced wallet it funds, and settles with the client directly. If the wallet runs low, billing pauses and the data is kept, so nobody receives an unexpected charge. At the end the partner hands the project over and the deployments become the client's own.

Credits can be bought in more than 20 currencies, including XAF, XOF, NGN, GHS, KES and ZAR, by card, bank transfer or mobile money.

Sources (8 October 2026): Google Cloud list prices from the Cloud Billing Catalog API; RAD fees and the daily-credit estimate from radmodules.dev/pricing; Delete and restore projects for the pause/restore window and backup-bucket caveat; Cal.com pricing; prices change, check each source before relying on a figure.

1. Overview​

Cal.com runs as a Next.js container on Cloud Run v2. The deployment wires together a focused set of Google Cloud services:

CapabilityGoogle Cloud serviceNotes
ComputeCloud Run v2Next.js service, 1 vCPU / 2 GiB by default, serverless autoscaling; scale-to-zero supported
DatabaseCloud SQL for PostgreSQL 15Required — Cal.com (Prisma/pg) targets PostgreSQL only
Object storageCloud Storage (none by default)Cal.com stores all state in PostgreSQL; no uploads bucket is created
CacheRedis (optional)Off by default; used for caching / rate limiting
SecretsSecret ManagerAuto-generated NEXTAUTH_SECRET and CALENDSO_ENCRYPTION_KEY; database password
IngressCloud Run URL / Cloud Load BalancingDefault run.app URL; optional external HTTPS load balancer + custom domain

Sensible defaults worth knowing up front:

  • PostgreSQL 15 is mandatory. The database engine is fixed by the shared application layer; Cal.com's Prisma schema targets PostgreSQL only.
  • NEXTAUTH_SECRET and CALENDSO_ENCRYPTION_KEY are generated automatically and stored in Secret Manager. Never rotate them after first boot without a maintenance window — rotating CALENDSO_ENCRYPTION_KEY renders all stored calendar/OAuth credentials undecryptable, and rotating NEXTAUTH_SECRET invalidates all sessions.
  • The public URL is validated at startup. NEXT_PUBLIC_WEBAPP_URL / NEXTAUTH_URL default to this service's deterministic run.app URL; leaving them at the image's localhost:3000 default makes the server refuse to boot. Set webapp_url to a custom domain before sharing booking links.
  • The schema is created on boot, not by a migration job. The db-init job only provisions the empty database and role; Cal.com runs prisma migrate deploy on every start. Allow several minutes on the first boot.
  • Memory floor is 2 GiB. Cal.com (Next.js 16) OOM-crashes at startup below 2 GiB.
  • Scale-to-zero is enabled by default (min_instance_count = 0, max = 1, request-based billing). Cold starts add latency to the first request after idle; set min_instance_count = 1 to avoid them.
  • The Cloud SQL Auth Proxy socket is used by default (enable_cloudsql_volume = true). A direct private-IP TCP connection fails Prisma's server-certificate verification against Cloud SQL's untrusted CA — the socket avoids this (the proxy does the mTLS).
  • Redis is disabled by default. Enable it only for cache / rate-limit backing.

2. Google Cloud Services & How to Explore Them​

All commands assume PROJECT and REGION are set. Service and resource names are reported in the deployment Outputs.

A. Cloud Run — the Cal.com service​

Cal.com runs as a Cloud Run v2 service that autoscales by request load between the minimum and maximum instance counts. Each deployment creates an immutable revision; traffic can be split across revisions for safe rollouts.

  • Console: Cloud Run → select the service for revisions, traffic, logs, and metrics.
  • CLI:
    gcloud run services list --project "$PROJECT" --region "$REGION"
    gcloud run services describe <service-name> --project "$PROJECT" --region "$REGION"
    gcloud run revisions list --service <service-name> --project "$PROJECT" --region "$REGION"

See App_CloudRun for scaling, concurrency, execution environment, and traffic splitting.

B. Cloud SQL for PostgreSQL 15​

Cal.com stores all application data (users, event types, bookings, connected calendar credentials) in a managed Cloud SQL for PostgreSQL 15 instance. The service connects privately through the Cloud SQL Auth Proxy over a Unix socket; no public IP is exposed. On first deploy an initialization Job creates the application database and role, and Cal.com applies its schema via Prisma on boot.

  • Console: SQL → select the instance for connections, backups, flags, metrics.
  • CLI:
    gcloud sql instances list --project "$PROJECT"
    gcloud sql instances describe <instance-name> --project "$PROJECT"
    gcloud sql connect <instance-name> --user=<db-user> --database=<db-name> --project "$PROJECT"

The instance name, database, user, and password secret are in the Outputs. See App_CloudRun for the connection model, backups, and password rotation.

C. Cloud Storage​

Cal.com keeps all state in PostgreSQL, so no data bucket is created by default (storage_buckets is empty). Additional buckets can still be declared via storage_buckets if needed for custom integrations.

  • Console: Cloud Storage → Buckets.
  • CLI:
    gcloud storage buckets list --project "$PROJECT"

See App_CloudRun for GCS Fuse and CMEK options.

D. Redis (optional cache)​

Redis is disabled by default (enable_redis = false). When enabled, Cal.com uses it as a cache / rate-limit backend. When redis_host is left empty and enable_nfs is true, the NFS server VM's IP is used as the Redis endpoint.

  • Console: Memorystore → Redis (if using a managed instance).
  • CLI:
    redis-cli -h <redis-host> ping
    redis-cli -h <redis-host> info keyspace
    # Confirm env injected into the running revision:
    gcloud run services describe <service-name> --region "$REGION" \
    --format='value(spec.template.spec.containers[0].env)'

E. Secret Manager​

Two cryptographic secrets are generated automatically and stored in Secret Manager: NEXTAUTH_SECRET (signs NextAuth.js session tokens) and CALENDSO_ENCRYPTION_KEY (encrypts stored calendar/OAuth credentials). The database password is managed separately by the foundation.

  • Console: Security → Secret Manager.
  • CLI:
    gcloud secrets list --project "$PROJECT"
    gcloud secrets versions access latest --secret=<secret-name> --project "$PROJECT"

See App_CloudRun for injection and rotation details.

F. Networking & ingress​

The service is reachable at its run.app URL by default (ingress_settings = "all"). An external HTTPS load balancer with a custom domain, Cloud CDN, and Cloud Armor can be layered on; ingress settings and VPC egress control connectivity. Because Cal.com bakes its public URL into generated booking and OAuth links, set webapp_url to the final domain before going live.

  • Console: Cloud Run (service URL); Network services → Load balancing.
  • CLI:
    gcloud run services describe <service-name> --region "$REGION" --format='value(status.url)'
    gcloud compute addresses list --project "$PROJECT"

See App_CloudRun.

G. Cloud Logging & Monitoring​

Container logs flow to Cloud Logging; Cloud Run and Cloud SQL metrics flow to Cloud Monitoring, with optional uptime checks and alert policies.

  • Console: Logging → Logs Explorer; Monitoring → Dashboards / Alerting.
  • CLI:
    gcloud run services logs read <service-name> --project "$PROJECT" --region "$REGION" --limit 50

3. Cal.com Application Behaviour​

  • First-deploy database setup. An initialization Job runs db-init.sh using postgres:15-alpine. It connects through the Cloud SQL Auth Proxy and idempotently creates the application role and database and grants privileges on the public schema. It does not create the application schema — that is Cal.com's job.
  • Schema migrations on boot. The image's start script runs prisma migrate deploy on every start, creating the schema on first boot and applying new migrations on version upgrades — no separate migration step. Budget several minutes for the first boot before the service becomes Ready.
  • NEXTAUTH_SECRET and CALENDSO_ENCRYPTION_KEY are immutable after first boot. Changing CALENDSO_ENCRYPTION_KEY makes all stored calendar/OAuth credentials undecryptable (every integration must be re-authorised); changing NEXTAUTH_SECRET logs out every user. Only rotate during a planned maintenance window.
  • Public URL is validated at startup. NEXT_PUBLIC_WEBAPP_URL / NEXTAUTH_URL default to the deterministic run.app URL and are corrected at runtime from CLOUDRUN_SERVICE_URL. Verify the deployed value:
    gcloud run services describe <service-name> \
    --region "$REGION" --project "$PROJECT" --format='value(status.url)'
  • First-run setup. Open the service URL and complete the Cal.com onboarding to create the initial administrator/owner account, then configure at least one connected calendar. Self-hosted Cal.com allows self-service sign-up by default — restrict it (or front the service with IAP) if the instance should not be public.
  • Startup probe is TCP, not HTTP. The / endpoint only returns 2xx once Cal.com reports FULL readiness (DB + Redis + deps), which never passed an HTTP startup probe even though Next.js was already listening on the port — so the default probe is a 30 s-delay TCP check (20 s period, 30 failure retries ≈ 10 minutes) that succeeds as soon as the app binds the port. The liveness probe is disabled by default for the same reason: Cloud Run liveness can't use a TCP socket, and the HTTP / endpoint would restart-loop an otherwise-healthy container while it's still reaching full readiness.
  • Inspect job execution:
    gcloud run jobs list --project "$PROJECT" --region "$REGION"
    gcloud run jobs executions list --job <job-name> --project "$PROJECT" --region "$REGION"

4. Configuration Variables​

Variables are grouped exactly as they appear on the deployment platform. Only settings specific to or notable for Cal.com are listed; every other input is inherited from App_CloudRun with its standard behaviour.

Group 1 — Project & Identity​

VariableDefaultDescription
project_id(required)Target Google Cloud project.
regionus-central1Region for the service and regional resources.

All other inputs follow standard App_CloudRun behaviour.

Group 3 — Application Identity​

VariableDefaultDescription
application_namecalcomBase name for resources. Do not change after first deploy.
display_nameCal.comHuman-readable name shown in the Console.
application_versionlatestCal.com image tag (sets CALCOM_VERSION); pin to a specific release in production.
webapp_url""Public URL for NEXT_PUBLIC_WEBAPP_URL/NEXTAUTH_URL. Empty → the deterministic run.app URL; set to a custom domain once known.

All other inputs follow standard App_CloudRun behaviour.

Group 4 — Runtime & Scaling​

VariableDefaultDescription
deploy_applicationtrueSet false to provision infrastructure only.
container_port3000Port Cal.com listens on.
cpu_limit1000mCPU per instance; Cal.com needs ≥ 1 vCPU.
memory_limit2GiMinimum 2 GiB — Next.js 16 OOM-crashes below it.
min_instance_count00 enables scale-to-zero; set 1 to avoid cold starts.
max_instance_count1Cost ceiling; raise for higher concurrency.
cpu_always_allocatedfalseRequest-based billing. Set true only if you run background reminder/notification workers.
execution_environmentgen2Gen2 required for NFS/GCS Fuse mounts.
enable_cloudsql_volumetrueAuth Proxy socket. Keep true — direct-IP TCP fails Prisma cert verification.
enable_image_mirroringtrueMirror the Cal.com image into Artifact Registry.

All other inputs follow standard App_CloudRun behaviour.

Group 5 — Access & Ingress Control​

VariableDefaultDescription
ingress_settingsallPublic access. Set internal/internal-and-cloud-load-balancing to restrict.
enable_iapfalseRequire Google sign-in in front of Cal.com.
iap_authorized_users / iap_authorized_groups[]Who may access through IAP.

All other inputs follow standard App_CloudRun behaviour.

Group 6 — Environment Variables & Secrets​

VariableDefaultDescription
environment_variables{}Extra non-secret settings. Do not set NEXTAUTH_SECRET, CALENDSO_ENCRYPTION_KEY, or DATABASE_URL here — they are managed automatically.
secret_environment_variables{}Map of env var → Secret Manager secret name (e.g. SMTP or OAuth app credentials).
secret_propagation_delay30Seconds to wait after secret creation before proceeding.

All other inputs follow standard App_CloudRun behaviour.

Group 11 — Storage & Filesystem​

VariableDefaultDescription
create_cloud_storagetrueCreate GCS buckets defined in storage_buckets (none by default).
storage_buckets[]Additional GCS buckets.
enable_nfstrueOptional shared volume; also hosts co-located Redis when enabled.
nfs_mount_path/mnt/nfsMount path inside the container.
gcs_volumes[]GCS Fuse volume mounts (requires gen2).

All other inputs follow standard App_CloudRun behaviour.

Group 12 — Database Backend​

VariableDefaultDescription
db_namecalcomPostgreSQL database name. Immutable after first deploy.
db_usercalcomApplication database user. Password auto-generated in Secret Manager.
database_typePOSTGRES_15Fixed to PostgreSQL 15; other engines are unsupported.
database_password_length32Generated password length.

All other inputs follow standard App_CloudRun behaviour.

Group 14 — Observability & Health​

VariableDefaultDescription
startup_probeTCP on the container port, 30s delay, 20s period, 30 retries (~10 min)TCP, not HTTP — the / endpoint only 2xxs once Cal.com is fully ready (DB + Redis + deps), which never passed as an HTTP gate even though the app was already listening.
liveness_probeHTTP /, disabled by defaultDisabled — the HTTP / endpoint would restart-loop a healthy container still reaching full readiness, and Cloud Run liveness can't use TCP.
uptime_check_config{ enabled=false, path="/" }Cloud Monitoring uptime check.
alert_policies[]Metric alert policies.

All other inputs follow standard App_CloudRun behaviour.

Group 21 — Redis Cache​

VariableDefaultDescription
enable_redisfalseEnable Redis as the cache / rate-limit backend.
redis_host""Redis endpoint. Leave empty to use the NFS server IP (requires enable_nfs = true).
redis_port6379Redis port.
redis_auth""Optional Redis auth password (sensitive).

All other inputs follow standard App_CloudRun behaviour.

Group 22 — VPC Service Controls & Audit Logging​

VariableDefaultDescription
enable_vpc_scfalseEnforce a VPC-SC perimeter (requires organization_id).
enable_audit_loggingfalseDetailed Cloud Audit Logs.

All other inputs follow standard App_CloudRun behaviour.


5. Outputs​

Returned on a successful deployment — the quickest way to locate and explore the running resources.

OutputDescription
service_nameCloud Run service name.
service_urlDefault run.app URL of the service.
service_locationRegion the service runs in.
stage_servicesStage-specific service URLs (Cloud Deploy).
load_balancer_ip / load_balancer_urlExternal HTTPS load balancer IP / URL (when enabled).
database_instance_nameCloud SQL instance name.
database_name / database_userApplication database name / user.
database_password_secretSecret Manager secret holding the DB password.
database_host / database_portDB endpoint / port.
storage_bucketsCreated Cloud Storage buckets (empty by default).
network_name / network_exists / regionsVPC network, presence, regions.
container_image / container_registryDeployed image and Artifact Registry repo.
monitoring_enabled / monitoring_notification_channels / uptime_check_namesMonitoring status, channels, uptime checks.
initialization_jobsNames of the setup jobs.
deployment_id / tenant_id / resource_prefixNaming identifiers.
project_id / project_numberProject identifiers.
cicd_enabled / github_repository_url / github_repository_owner / github_repository_name / cicd_configurationCI/CD status and details.
artifact_registry_repository / cloudbuild_trigger_name / cloudbuild_trigger_idRegistry and build trigger.
vpc_sc_enabled / vpc_sc_perimeter_name / vpc_sc_dry_run_modeVPC-SC status.
audit_logging_enabled / artifact_registry_cmek_enabledAudit logging and CMEK status.

6. Configuration Pitfalls & Sensible Defaults​

Risk: Critical (data loss / outage / security) — High (service degraded) — Medium (cost or partial degradation) — Low (minor).

Inherited plan-time validation. This module passes its configuration through the App_CloudRun foundation engine, which validates values and combinations at plan time — IAP with no authorized identities, a gen1 runtime with NFS/GCS mounts, a database_type that does not match an enabled extension, an out-of-range redis_port/backup_retention_days. Invalid configuration fails the plan with a clear, named error before any resource is created, so most mistakes below are caught up front rather than at apply or runtime.

SettingSensible valueRiskConsequence if wrong
CALENDSO_ENCRYPTION_KEY (auto-generated)Never rotate after first bootCriticalRotating it makes all stored calendar/OAuth credentials undecryptable — every integration must be re-authorised.
NEXTAUTH_SECRET (auto-generated)Only rotate in a maintenance windowCriticalRotating it invalidates all active user sessions, forcing immediate re-login.
db_name / db_userSet onceCriticalImmutable after first deploy; renaming recreates the DB/user and destroys all data.
database_typePOSTGRES_15CriticalCal.com's Prisma schema targets PostgreSQL only; any other engine breaks startup.
webapp_urlFinal public URLCriticalA wrong or unset URL is baked into every booking/OAuth link, and the image default (localhost:3000) makes the server refuse to boot.
enable_cloudsql_volumetrueHighDirect private-IP TCP fails Prisma's cert verification against Cloud SQL's CA — every query 500s. Keep the Auth Proxy socket.
memory_limit2GiHighBelow 2 GiB, Next.js 16 OOM-crashes at startup and the revision never becomes Ready.
enable_iaponly for private instancesHighIAP blocks all unauthenticated requests — including embeds and public booking pages.
Open sign-updisable for private instancesHighSelf-hosted Cal.com allows self-service sign-up; leaving it open lets anyone with the URL create an account.
min_instance_count1 for latency-sensitive useMediumScale-to-zero (0) adds cold-start delay on the first request after idle.
startup_probe typekeep TCPMediumSwitching to HTTP against / fails until Cal.com reports full readiness (DB + Redis + deps), wedging the rollout even though the app is already listening.
backup_retention_days7 (raise for prod)MediumToo short for compliance retention.

For the foundation behaviour referenced throughout — service identity, scaling and concurrency, ingress and load balancing, CI/CD, Cloud Armor, IAP, Binary Authorization, VPC-SC, backups, and image mirroring — see App_CloudRun. Cal.com-specific application configuration shared with the GKE variant is described in CalCom_Common.

Need RAD to do something it does not do yet? Request it on the roadmap, or vote on what is already there.