> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cognite.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Environment variables

> The Cognite Toolkit supports injecting environment variables into the configuration files to inject secrets or other sensitive information.

The Cognite Toolkit injects environment variables in the `cdf deploy/clean/pull` commands. You don't need to declare environment variables. The Cognite Toolkit will inject all the variables into the OS environment. The syntax
for injecting environment variables is `${MY_ENV_VAR}` and you can place it anywhere in the configuration file.

For example, if you have the following configuration file for a workflow trigger:

```yaml title="my_trigger.WorkflowTrigger.yaml" theme={"languages":{"custom":["/_languages/kuiper.json","../_languages/kuiper.json"]}}
externalId: my_trigger
triggerRule:
  triggerType: schedule
  cronExpression: '0 0 * * *'
metadata:
  origin: cognite-toolkit
workflowExternalId: wf_my_workflow
workflowVersion: '1'
authentication:
  clientId: ${IDP_WF_TRIGGER_CLIENT_ID}
  clientSecret: ${IDP_WF_TRIGGER_SECRET}
```

Then, in your environment, you'll have the following environment variables:

```text theme={"languages":{"custom":["/_languages/kuiper.json","../_languages/kuiper.json"]}}
IDP_WF_TRIGGER_CLIENT_ID=my_client_id
IDP_WF_TRIGGER_SECRET=my_secret
```

When you run the `cdf deploy` command, the Cognite Toolkit injects the environment variables into the configuration file.

```yaml title="my_trigger.WorkflowTrigger.yaml" theme={"languages":{"custom":["/_languages/kuiper.json","../_languages/kuiper.json"]}}
externalId: my_trigger
triggerRule:
  triggerType: schedule
  cronExpression: '0 0 * * *'
metadata:
    origin: cognite-toolkit
workflowExternalId: wf_my_workflow
workflowVersion: '1'
authentication:
  clientId: my_client_id
  clientSecret: my_secret
```

<Warning>
  The Cognite Toolkit doesn't inject environment variables for `ExtractionPipelineConfig` in the `config` parameter. This is because the extraction pipeline configurations and the Cognite Toolkit use the same syntax for injecting environment variables.
</Warning>

## Environment variables with build variables

The environment variables are independent of the [build variables](/cdf/deploy/cdf_toolkit/api/config_yaml#the-variables-section)
specified in the `config.[env].yaml` file and used in the `cdf build` command.
You can combine the environment and build variables together.

For example, you can define a function schedule in `modules/my_module/functions/my_function.Function.yaml`:

```yaml title="my_function.Function.yaml" theme={"languages":{"custom":["/_languages/kuiper.json","../_languages/kuiper.json"]}}
name: daily-8am
cronExpression: '0 8 * * *'
functionExternalId: my_function
authentication:
  clientId: {{ functionClientId }}
  clientSecret: {{ functionClientSecret }}
```

Then, in your `config.dev.yaml` file, you'll have the following build variables:

```yaml title="config.dev.yaml" theme={"languages":{"custom":["/_languages/kuiper.json","../_languages/kuiper.json"]}}
variables:
  modules:
    functionClientId: ${IDP_FUNCTION_CLIENT_ID}
    functionClientSecret: ${IDP_FUNCTION_CLIENT_SECRET}
```

When you run `cdf build` command, the Cognite Toolkit replaces the `{{ functionClientId }}` and `{{ functionClientSecret }}` with the environment variable placeholders. Hence, after running `cdf build`, your function schedule configuration in `build/functions/1.my_function.Function.yaml` will look like:

```yaml title="my_function.Function.yaml" theme={"languages":{"custom":["/_languages/kuiper.json","../_languages/kuiper.json"]}}
name: daily-8am
cronExpression: '0 8 * * *'
functionExternalId: my_function
authentication:
  clientId: ${IDP_FUNCTION_CLIENT_ID}
  clientSecret: ${IDP_FUNCTION_CLIENT_SECRET}
```

In `cdf deploy` command, specify the environment variables, `IDP_FUNCTION_CLIENT_ID` and `IDP_FUNCTION_CLIENT_SECRET`.
The Cognite Toolkit will inject these environment variables into the configuration file.

```yaml title="my_function.Function.yaml" theme={"languages":{"custom":["/_languages/kuiper.json","../_languages/kuiper.json"]}}
name: daily-8am
cronExpression: '0 8 * * *'
functionExternalId: my_function
authentication:
  clientId: my_client_id
  clientSecret: my_secret
```