From 5036ae46548365cf16499e25555c5b3a970bac88 Mon Sep 17 00:00:00 2001
From: Barrett Ruth <br.barrettruth@gmail.com>
Date: Tue, 30 Dec 2025 19:31:37 -0600
Subject: [PATCH] feat: open mdx post urls in a new tab

---
 astro.config.mjs | 14 ++++++++++++--
 package.json     |  1 +
 pnpm-lock.yaml   | 21 +++++++++++++++++++++
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/astro.config.mjs b/astro.config.mjs
index f1fd94c..cecd5c9 100644
--- a/astro.config.mjs
+++ b/astro.config.mjs
@@ -1,7 +1,8 @@
 import { defineConfig } from "astro/config";
 import mdx from "@astrojs/mdx";
-import remarkMath from "remark-math";
+import rehypeExternalLinks from "rehype-external-links";
 import rehypeKatex from "rehype-katex";
+import remarkMath from "remark-math";
 import path from "path";
 
 const midnight = {
@@ -73,7 +74,16 @@ export default defineConfig({
   integrations: [
     mdx({
       remarkPlugins: [remarkMath],
-      rehypePlugins: [rehypeKatex],
+      rehypePlugins: [
+        rehypeKatex,
+        [
+          rehypeExternalLinks,
+          {
+            target: "_blank",
+            rel: ["noopener", "noreferrer"],
+          },
+        ],
+      ],
     }),
   ],
   vite: {
diff --git a/package.json b/package.json
index 3afab55..1cdab3e 100644
--- a/package.json
+++ b/package.json
@@ -19,6 +19,7 @@
   "dependencies": {
     "@astrojs/mdx": "^4.3.6",
     "astro": "^5.14.1",
+    "rehype-external-links": "^3.0.0",
     "rehype-katex": "^7.0.1",
     "remark-math": "^6.0.0"
   },
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index b5081b7..288fd53 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -14,6 +14,9 @@ importers:
       astro:
         specifier: ^5.14.1
         version: 5.14.1(@types/node@24.7.0)(rollup@4.52.4)(typescript@5.9.3)(yaml@2.8.1)
+      rehype-external-links:
+        specifier: ^3.0.0
+        version: 3.0.0
       rehype-katex:
         specifier: ^7.0.1
         version: 7.0.1
@@ -1308,6 +1311,10 @@ packages:
   iron-webcrypto@1.2.1:
     resolution: {integrity: sha512-feOM6FaSr6rEABp/eDfVseKyTMDt+KGpeB35SkVn9Tyn0CqvVsY3EwI0v5i8nMHyJnzCIQf7nsy3p41TPkJZhg==}
 
+  is-absolute-url@4.0.1:
+    resolution: {integrity: sha512-/51/TKE88Lmm7Gc4/8btclNXWS+g50wXhYJq8HWIBAGUBnoAdRu1aXeh364t/O7wXDAcTJDP8PNuNKWUDWie+A==}
+    engines: {node: ^12.20.0 || ^14.13.1 || >=16.0.0}
+
   is-alphabetical@2.0.1:
     resolution: {integrity: sha512-FWyyY60MeTNyeSRpkM2Iry0G9hpr7/9kD40mD/cGQEuilcZYS4okz8SN2Q6rLCJ8gbCt6fN+rC+6tMGS99LaxQ==}
 
@@ -1830,6 +1837,9 @@ packages:
   regex@6.0.1:
     resolution: {integrity: sha512-uorlqlzAKjKQZ5P+kTJr3eeJGSVroLKoHmquUj4zHWuR+hEyNqlXsSKlYYF5F4NI6nl7tWCs0apKJ0lmfsXAPA==}
 
+  rehype-external-links@3.0.0:
+    resolution: {integrity: sha512-yp+e5N9V3C6bwBeAC4n796kc86M4gJCdlVhiMTxIrJG5UHDMh+PJANf9heqORJbt1nrCbDwIlAZKjANIaVBbvw==}
+
   rehype-katex@7.0.1:
     resolution: {integrity: sha512-OiM2wrZ/wuhKkigASodFoo8wimG3H12LWQaH8qSPVJn9apWKFSH3YOCtbKpBorTVw/eI7cuT21XBbvwEswbIOA==}
 
@@ -3889,6 +3899,8 @@ snapshots:
 
   iron-webcrypto@1.2.1: {}
 
+  is-absolute-url@4.0.1: {}
+
   is-alphabetical@2.0.1: {}
 
   is-alphanumerical@2.0.1:
@@ -4683,6 +4695,15 @@ snapshots:
     dependencies:
       regex-utilities: 2.3.0
 
+  rehype-external-links@3.0.0:
+    dependencies:
+      '@types/hast': 3.0.4
+      '@ungap/structured-clone': 1.3.0
+      hast-util-is-element: 3.0.0
+      is-absolute-url: 4.0.1
+      space-separated-tokens: 2.0.2
+      unist-util-visit: 5.0.0
+
   rehype-katex@7.0.1:
     dependencies:
       '@types/hast': 3.0.4