You can directly pass JSON to Terraform by putting it in a `.tfvars.json` file [1], as far as I can tell this has been supported since v0.5.0 which released in May 2015.

Terraform doesn't have a built-in deep merge function, but it will merge `.tfvars.json` files in the order given on the CLI, if you specify multiple `-var-file` arguments. For what it's worth, as of Terraform 1.8, you can also use functions from third-party providers like isometry/deepmerge [2] to perform a deep merge.

[1] https://developer.hashicorp.com/terraform/language/parameter... [2] https://registry.terraform.io/providers/isometry/deepmerge/l...