Document parameterized markdown snippets feature (#1865)

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Catherine Deskur <[email protected]>
Co-authored-by: Devin Logan <[email protected]>

Author: 3 people

fern/assets/styles.css

@@ -1082,7 +1082,8 @@ h1, h2, h3 {
 /*** END -- LANDING PAGE STYLING ***/
 
 /* HACK: add a slash to markdown snippet documentation (otherwise it gets parsed by CLI) */
-.modify-snippet tbody tr:last-of-type td:last-of-type .line span:last-of-type:before {
+.modify-snippet tbody tr:nth-child(1) td:last-of-type .line span:last-of-type:before,
+.modify-snippet tbody tr:nth-child(5) td:last-of-type .line span:last-of-type:before {
   content: "/";
   display: inline-block;
 }

fern/products/docs/pages/changelog/2025-11-08.mdx

@@ -1,3 +1,25 @@
+## Parameterized markdown snippets
+
+Reusable Markdown snippets support arbitrary parameters that can be used as variables in the snippet. This enables flexible, reusable content templates.
+
+Create a snippet with parameter placeholders using curly braces:
+
+```mdx fern/snippets/watering-schedule.mdx
+<Warning>Remember to water your {plant} every {interval} days.</Warning>
+```
+
+Pass parameters when including the snippet:
+
+```mdx page.mdx
+<Markdown src="/snippets/watering-schedule.mdx" plant="peace lily" interval="3" />
+```
+
+This renders as:
+
+<Markdown src="/snippets/watering-schedule.mdx" plant="peace lily" interval="3" />
+
+Learn more about [reusable Markdown snippets](/learn/docs/writing-content/reusable-snippet).
+
 ## New Copy component for inline copyable text
 
 The `<Copy>` component makes text copyable with a single click. Use it inline to allow readers to quickly copy version numbers, commands, API keys, or other text snippets without selecting and copying manually.

fern/products/docs/pages/component-library/custom-components/reusable-markdown.mdx

@@ -27,28 +27,38 @@ fern
 In each snippet file, define the content you want to reuse.
 
 ```mdx title="snippets/peace-lily.mdx"
-<Warning> Remember to water your plant at least twice a week. </Warning>
+Peace lilies are easy to grow and relatively trouble-free.
 ```
+
+Optionally, you can use parameters in your snippet:
+```mdx title="snippets/watering-schedule.mdx"
+<Warning>Remember to water your {plant} every {interval} days.</Warning>
+```
+
 </Step>
 <Step title="Use a snippet">
 
-To use a snippet in your documentation, reference it by its file path (including the `.mdx` extension). For example, to include the `peace-lily` snippet from the folder structure above:
+To use a snippet in your documentation, reference it by its file path (including the `.mdx` extension). If you used one or more parameters in your snippet, pass them in the snippet reference:
 
 <Tabs>
     <Tab title="Markdown">
         <div className="modify-snippet">
         ```jsx
-        Peace lilies are easy to grow and relatively trouble-free.
-
         <Markdown src="/snippets/peace-lily.mdx">
+
+        They symbolize peace and prosperity.
+
+        <Markdown src="/snippets/watering-schedule.mdx" plant="peace lily" interval="3">
         ```
         </div>
 
     </Tab>
     <Tab title="Preview">
-        Peace lilies are easy to grow and relatively trouble-free.
-        
         <Markdown src="/snippets/peace-lily.mdx" />
+
+        They symbolize peace and prosperity.
+
+        <Markdown src="/snippets/watering-schedule.mdx" plant="peace lily" interval="3" />
     </Tab>
 </Tabs>
 
@@ -62,4 +72,5 @@ To use a snippet in your documentation, reference it by its file path (including
     | `fern/docs/guides/snippets/peace-lily.mdx` | `src="/docs/guides/snippets/peace-lily.mdx"` |
 </Note>
 </Step>
-</Steps>
+
+</Steps>

fern/snippets/peace-lily.mdx

@@ -1 +1 @@
-<Warning> Remember to water your plant at least twice a week. </Warning>
+Peace lilies are easy to grow and relatively trouble-free.

fern/snippets/watering-schedule.mdx

@@ -0,0 +1 @@
+<Warning>Remember to water your {plant} every {interval} days.</Warning>