terraform/website/docs/language/resources/ephemeral/reference.mdx

---
page_title: Ephemeral block configuration reference
description: Learn to define ephemeral blocks in Terraform configurations to keep temporary and sensitive information out of Terraform state and plan files.
---

# Ephemeral block configuration reference

This topic provides reference information for the `ephemeral` block. 

-> **Note**: Ephemeral resources are available in Terraform v1.10 and later.

## Introduction

Ephemeral resources are Terraform resources that are essentially temporary. Ephemeral resources have a unique lifecycle, and Terraform does not store them in its state. Each `ephemeral` block describes one or more ephemeral resources, such as a temporary password or connection to another system.

## Dependency graph

Ephemeral resources form nodes in Terraform's dependency graph, which interact similarly as resources and data sources. For example, when a resource or data source depends on an attribute of an ephemeral resource, Terraform automatically provisions the ephemeral resource first.

## Defer provisioning

If an input argument of an ephemeral resource references a value that Terraform does not know yet, but can learn during or after a plan, Terraform defers executing that resource until the apply stage. Deferring execution lets Terraform ensure it has all of the information it needs to properly provision the ephemeral resource.

## Configuration model

An `ephemeral` block declares an ephemeral resource of a specific type with a
specific local name, much like a `resource` block. Terraform uses an ephemeral resource's name to refer to that resource in the same module, but an ephemeral resource's name has no meaning outside that module's scope.

Most of the arguments within the body of an `ephemeral` block are specific to the ephemeral resource you are defining. As with resources and data sources, each provider in the [Terraform Registry](https://registry.terraform.io/browse/providers) includes documentation for the ephemeral resources it supports, if any. An ephemeral resource type's documentation lists which arguments are available and how you should format your resource's values. 

The following list outlines general field hierarchy, language-specific data types, and requirements in the `ephemeral` block. 

- [`ephemeral`](#ephemeral): map
  - [`attributes`](#ephemeral)
  - [`meta-arguments`](#ephemeral)

## Complete configuration

An `ephemeral` block has the following form:

```hcl
ephemeral "<resource_type>" "<resource_name>" {
  <attributes>
  <meta-arguments>
}
```

## Reference ephemeral resources

You can only reference ephemeral resources in specific ephemeral contexts or
Terraform throws an error. The following are valid contexts for referencing
ephemeral resources:

* In a [write-only argument](/terraform/language/resources/ephemeral/write-only)
* In another ephemeral resource
* In [local values](/terraform/language/values/locals#ephemeral-values)
* In [ephemeral variables](/terraform/language/values/variables#exclude-values-from-state)
* In [ephemeral outputs](/terraform/language/values/outputs#ephemeral-avoid-storing-values-in-state-or-plan-files)
* Configuring providers in the `provider` block
* In [provisioner](/terraform/language/resources/provisioners/syntax) and [connection](/terraform/language/resources/provisioners/connection) blocks

## Meta-arguments

You can use the following meta-arguments with ephemeral resources to change the behavior of those resources. The following meta-arguments work the same way for resources, data sources, and ephemeral
resources:

- [`depends_on`, for specifying hidden dependencies](/terraform/language/meta-arguments/depends_on)
- [`count`, for creating multiple resource instances according to a count](/terraform/language/meta-arguments/count)
- [`for_each`, to create multiple instances according to a map or set of strings](/terraform/language/meta-arguments/for_each)
- [`provider`, for selecting a non-default provider configuration](/terraform/language/meta-arguments/resource-provider)
- [`lifecycle`, for lifecycle customizations](/terraform/language/meta-arguments/lifecycle)

Ephemeral resources do not support the `provisioner` meta-argument.

## Example

The following example configures the `postgresql` provider with credentials from
an ephemeral resource. Since these credentials are managed by an ephemeral resource, Terraform does not store them in your state or plan files.

```hcl
ephemeral "aws_secretsmanager_secret_version" "db_master" {
  secret_id = aws_secretsmanager_secret_version.db_password.secret_id
}

locals {
  credentials = jsondecode(ephemeral.aws_secretsmanager_secret_version.db_master.secret_string)
}

provider "postgresql" {
  host     = aws_db_instance.example.address
  port     = aws_db_instance.example.port
  username = local.credentials["username"]
  password = local.credentials["password"]
}
```