env file

@branchly/resolver-env-file is the default resolver: after provisioning, it upserts the branch’s connection string into your .env file, so anything that reads .env — your app, Prisma, scripts — picks up the right database automatically.

Configuration

resolver: {
  use: 'env-file',
  file: '.env',
  key: 'DATABASE_URL',
}

Option	Default	Meaning
file	'.env'	The env file to write into.
key	'DATABASE_URL'	The variable to set.

Behavior

The write is an upsert: an existing DATABASE_URL= line is replaced in place, every other line is left exactly as it was, and the key is appended if absent. Your comments and other variables survive every branch switch.

branchly init makes sure the file is gitignored — the value changes per branch and per machine, so it should never be committed.

Using Doppler or CI-injected environments where a file write would be overridden at launch? Pair this with branchly run, or use the direnv resolver.