EdgeDB on Fly

EdgeDB is a graph-relational database that runs on top of Postgres and is designed as a spiritual successor to SQL. This guide explains how to perform a single-region deployment of EdgeDB with persistent storage. It will require two apps: one for Postgres and one for the EdgeDB container.

Create the Postgres app

Create a Postgres app. You’ll need to replace mypostgres with a unique name of your choosing.

flyctl postgres create \
  --name mypostgres \
  --vm-size performance-1x \
  --volume-size 10 \
  --initial-cluster-size 1
Automatically selected personal organization: <Your Name>
? Select region: sea (Seattle, Washington (US))
Creating postgres cluster mypostgres in organization personal
Postgres cluster mypostgres created
  Username:    postgres
  Password:    <generated passworD>
  Hostname:    mypostgres.internal
  Proxy Port:  5432
  PG Port: 5433
Save your credentials in a secure place, you won't be able to see them again! 

Create the EdgeDB app

Create a directory and create a new app. Be sure to replace myedgedb with a custom name. When prompted, pick a region and a Fly organization.

flyctl launch --name myedgedb --image edgedb/edgedb --no-deploy

Since we’re using flyctl launch, this will create a fly.toml. All flyctl commands will now be applied against our myedgedb application unless otherwise specified with --app.

EdgeDB needs more RAM than the default 256MB so let’s scale the RAM to 1024MB.

flyctl scale memory 1024

Set a password for the EdgeDB instance as a Fly secret. Keep track of this password; it won’t be visible again.

flyctl secrets set EDGEDB_PASSWORD=mysecretpassword

We need to configure a few other environment variables too.

flyctl secrets set \
  EDGEDB_SERVER_TLS_CERT_MODE=generate_self_signed \

Let’s discuss what’s going on with all these secrets.

  • EDGEDB_SERVER_BACKEND_DSN_ENV tells EdgeDB which environment variable holds the Postgres connection string.
  • EDGEDB_SERVER_TLS_CERT_MODE tells EdgeDB to auto-generate a self-signed TLS certificate.
    • You may instead choose to provision a custom TLS certificate. In this case, you should instead create two other secrets: assign your certificate to EDGEDB_SERVER_TLS_CERT and your private key to EDGEDB_SERVER_TLS_KEY.
  • EDGEDB_SERVER_PORT tells EdgeDB to listen on port 8080 instead of the default 5656, as Fly uses 8080 for its default health checks.

Attach and deploy

Let’s attach mypostgres to myedgedb.

flyctl postgres attach mypostgres

This sets the value of DATABASE_URL in the myedgedb app and creates a new role called myedgedb in our Postgres database. By default, this role doesn’t have the full set of permissions EdgeDB needs to run. To change that, open a connection to your Postgres instance.

flyctl postgres connect --app mypostgres
Connecting to mypostgres.internal... complete
psql (14.4 (Debian 14.4-1.pgdg110+1))
Type "help" for help.


Then run the following REPL command.

postgres=# alter role myedgedb createrole createdb;
postgres=# \quit

Finally, our EdgeDB app is ready to deploy!

flyctl deploy

It make take a few minutes to fully deploy. Debug with flyctl logs and check the deployment status with flyctl status.

flyctl status

Persist certificates

We need to persist the auto-generated TLS certificate to make sure it survives EdgeDB app restarts. (If you’ve provided your own certificate, skip this step.)

flyctl ssh console \
  -C "edgedb-show-secrets.sh --format=toml EDGEDB_SERVER_TLS_KEY EDGEDB_SERVER_TLS_CERT" \
  | tr -d '\r' | flyctl secrets import


You’ll be able to connect to your EdgeDB instance using the following DSN from other Fly.io apps in the same organization:


To pass this DSN to another app, create a secret called EDGEDB_DSN containing this value. EdgeDB’s client libraries will read this environment variable and connect to your instance automatically.

flyctl secrets set \
  EDGEDB_DSN=edgedb://edgedb:mysecretpassword@myedgedb.internal:8080 \
  --app my-other-app

If you’ve configured a Wireguard tunnel on your local machine, you’ll be able to open a REPL to your new EdgeDB instance with the edgedb CLI.

edgedb --dsn edgedb://edgedb:mysecretpassword@myedgedb.internal:8080 --tls-security insecure
EdgeDB 2.x (repl 2.x.x)
Type \help for help, \quit to quit.