---
schema_version: "1"
id: 7f3a2e58c852258812f804715fc7775f06b1a6e1a3890945014edde4255a58c1
title: Configure Property Placeholders
collection: mulesoft
version: current
locale: en-us
portal_url: https://docs.salesforce.com/mulesoft/current/en-us/mule-runtime/4.6/mule-app-properties-to-configure.md
canonical_url: https://docs.mulesoft.com/mule-runtime/4.6/mule-app-properties-to-configure
source_site: docs.mulesoft.com
content_type: documentation
content_hash: 079e2832f2d3d89627001159b8bb2e8950ccf7fba21a47f1af6e6a9d333836db
description: MuleSoft Documentation Site
release: "4.6"
latest: false
---
---
product: Mule Runtime
version: 4.6
---

# Configure Property Placeholders

> For the full documentation index, see: https://docs.mulesoft.com/llms.txt

Instead of using static values for your Mule application configurations, such as connections, you
can create a `.yaml` or a `.properties` file to contain your properties and then reference the
properties from your application.

Configuring a properties file improves the organization and maintainability of your applications.

In a `.yaml` file, the properties take this form:

```yaml
http:
  path: "/service"
  port: "10000"
  host: "my-api.cloudhub.io"
```

In a `.properties` file, the properties take this form:

http.path=/service http.port=10000 http.host=my-api.cloudhub.io

## Create and Configure your Properties File

1.  In Studio, go to the **Package Explorer** view and right-click the `/src/main/resources` folder
    in your project.

2.  Select **New** > **File**:

    ![new-file-properties](/mulesoft/current/en-us/mule-runtime/4.6/_images/mruntime-properties-new-file.png)

3.  Choose a name for your file and set the extension to `.yaml`, or `.properties` if you prefer to
    use this format.

4.  Edit the file to define the properties and values you need.

5.  Add the properties file to your Mule application.

    - From Studio:

      1.  Open the **Global Elements** tab, and click the **Create** button.

      2.  Search for the element called Configuration Properties and click **OK**.

      3.  Click on the **…​** button and navigate to your `.yaml` or `.properties` file.

    - From the XML Editor:

      1.  Include a `<configuration-properties>` element inside `<mule>`, and set its `file`
          parameter with your properties file name. For example:

          ```xml
          <mule>
            <configuration-properties
              file="myConfiguration.yaml"
              doc:name="Configuration properties"
              doc:id="872422be-3571-4a52-a383-a2b0e16859d7" />`
            ...
          </mule>
          ```

## Use the Properties in your Application

Once you have configured your properties file and added it to your project, you can reference its
attributes by using a syntax like this: `${propertyContainer.propertyName}`.

Based on the examples configured in the previous section, to use the `path` and `port` values the
syntax is `${http.path}` and `${http.port}` respectively.

For example, you can configure your Global HTTP Request configuration to use the values defined in
the properties file.

- From Studio:

![properties-file](/mulesoft/current/en-us/mule-runtime/4.6/_images/mruntime-properties-file.png)

- From the XML Editor

  ```xml
  <http:request-config
    name="HTTP_Request_config"
    doc:name="HTTP Request
    configuration" doc:id="7120494c-0540-4ad1-a118-f5b6db3f1456"
    basePath="${http.path}" >
  		<http:request-connection
        host="${http.host}"
        port="${http.port}" />
  </http:request-config>
  ```

When the application is deployed, the property values are computed from the different possible
sources and statically replace the placeholders as if they were written directly in the source code.

Based on the previous example, the configuration looks like this:

```xml
<http:request-config
  name="HTTP_Request_config"
  doc:name="HTTP Request
  configuration" doc:id="7120494c-0540-4ad1-a118-f5b6db3f1456"
  basePath="/service" >
		<http:request-connection
      host="my-api.cloudhub.io"
      port="10000" />
</http:request-config>
```

There is no escaping special characters based on the context. The resulting values need to be valid
in the context from which they are referenced.

Consider the following example, which contains a DataWeave script:

```xml
<ee:transform>
  <ee:message>
    <ee:set-payload>
      <![CDATA[
        %dw 2.0
        output application/json
        ---
        {
          "message": "${message}",
        }
      ]]>
    </ee:set-payload>
  </ee:message>
</ee:transform>
```

The contents of the `.properties` file:

message=I love $

After property replacements take place, the application looks like this:

```xml
<ee:transform>
  <ee:message>
    <ee:set-payload>
      <![CDATA[
        %dw 2.0
        output application/json
        ---
        {
          "message": "I love $",
        }
      ]]>
    </ee:set-payload>
  </ee:message>
</ee:transform>
```

The output is an invalid DataWeave script because the dollar sign ($) has a special meaning and
needs to be escaped. See
[Dataweave - Escaping Special Characters](https://docs.mulesoft.com/dataweave/latest/dataweave-types#escape-chars-string).
Remember the property placeholders are replaced before the DataWeave script is parsed.

To solve conflicts, you can escape the value in the properties file:

message=I love \\$

Or use DataWeave [p function](https://docs.mulesoft.com/dataweave/latest/dw-mule-functions-p) instead of a property
placeholder:

```xml
<ee:transform>
  <ee:message>
    <ee:set-payload>
      <![CDATA[
        %dw 2.0
        output application/json
        ---
        {
          "message": Mule::p("message"),
        }
      ]]>
    </ee:set-payload>
  </ee:message>
</ee:transform>
```

The property is evaluated when the script is executed and the script remains syntactically valid at
the moment of parsing.

## See Also

- [Configure Properties](https://docs.mulesoft.com/mule-runtime/4.6/configuring-properties)