Example gmrc from https://github.com/graphile/starter/blob/master/.gmrc (not published at time of writing)

.gmrc

{
  "pgSettings": {
    "search_path": "app_public,app_private,app_hidden,public"
  },
  "placeholders": {
    ":DATABASE_AUTHENTICATOR": "!ENV",
    ":DATABASE_VISITOR": "!ENV"
  },
  "afterReset": [
    "afterReset.sql",
    {
      "_": "command",
      "command": "cd backend/dist/worker && npx --no-install graphile-worker --once"
    }
  ],
  "afterAllMigrations": [
    {
      "_": "command",
      "shadow": true,
      "command": "if [ \"$IN_TESTS\" != \"1\" ]; then ./scripts/dumpdb; fi"
    }
  ],
  "afterCurrent": [
    {
      "_": "command",
      "shadow": true,
      "command": "if [ \"$IN_TESTS\" = \"1\" ]; then node scripts/test_seed.js; fi"
    }
  ]
}