Add KaTeX math rendering via remark-math + rehype-katex

$...$ and $$...$$ LaTeX expressions were rendering as raw text.
Added remark-math to parse math nodes and rehype-katex to render
them as proper equations.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ui/package-lock.json

@@ -14,7 +14,9 @@
         "react-dom": "^19.2.4",
         "react-markdown": "^10.1.0",
         "react-syntax-highlighter": "^16.1.1",
-        "remark-gfm": "^4.0.1"
+        "rehype-katex": "^7.0.1",
+        "remark-gfm": "^4.0.1",
+        "remark-math": "^6.0.0"
       },
       "devDependencies": {
         "@eslint/js": "^9.39.4",
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       "dev": true
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+    "node_modules/@types/katex": {
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+      "resolved": "https://registry.npmjs.org/@types/katex/-/katex-0.16.8.tgz",
+      "integrity": "sha512-trgaNyfU+Xh2Tc+ABIb44a5AYUpicB3uwirOioeOkNPPbmgRNtcWyDeeFRzjPZENO9Vq8gvVqfhaaXWLlevVwg=="
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       "resolved": "https://registry.npmjs.org/@types/mdast/-/mdast-4.0.4.tgz",
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       "dev": true
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+    "node_modules/entities": {
+      "version": "6.0.1",
+      "resolved": "https://registry.npmjs.org/entities/-/entities-6.0.1.tgz",
+      "integrity": "sha512-aN97NXWF6AWBTahfVOIrB/NShkzi5H7F9r1s9mD3cDj4Ko5f2qhhVoYMibXF7GlLveb/D2ioWay8lxI97Ven3g==",
+      "engines": {
+        "node": ">=0.12"
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+      "funding": {
+        "url": "https://github.com/fb55/entities?sponsor=1"
+      }
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     "node_modules/esbuild": {
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@@ -2960,6 +2978,83 @@
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+        "hastscript": "^9.0.0",
+        "web-namespaces": "^2.0.0"
+      },
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+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/hast-util-from-html": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/hast-util-from-html/-/hast-util-from-html-2.0.3.tgz",
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+      "dependencies": {
+        "@types/hast": "^3.0.0",
+        "devlop": "^1.1.0",
+        "hast-util-from-parse5": "^8.0.0",
+        "parse5": "^7.0.0",
+        "vfile": "^6.0.0",
+        "vfile-message": "^4.0.0"
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+        "url": "https://opencollective.com/unified"
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+    "node_modules/hast-util-from-html-isomorphic": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/hast-util-from-html-isomorphic/-/hast-util-from-html-isomorphic-2.0.0.tgz",
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+      "dependencies": {
+        "@types/hast": "^3.0.0",
+        "hast-util-from-dom": "^5.0.0",
+        "hast-util-from-html": "^2.0.0",
+        "unist-util-remove-position": "^5.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
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+    "node_modules/hast-util-from-parse5": {
+      "version": "8.0.3",
+      "resolved": "https://registry.npmjs.org/hast-util-from-parse5/-/hast-util-from-parse5-8.0.3.tgz",
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+      "dependencies": {
+        "@types/hast": "^3.0.0",
+        "@types/unist": "^3.0.0",
+        "devlop": "^1.0.0",
+        "hastscript": "^9.0.0",
+        "property-information": "^7.0.0",
+        "vfile": "^6.0.0",
+        "vfile-location": "^5.0.0",
+        "web-namespaces": "^2.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/hast-util-is-element": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/hast-util-is-element/-/hast-util-is-element-3.0.0.tgz",
+      "integrity": "sha512-Val9mnv2IWpLbNPqc/pUem+a7Ipj2aHacCwgNfTiK0vJKl0LF+4Ba4+v1oPHFpf3bLYmreq0/l3Gud9S5OH42g==",
+      "dependencies": {
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+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/hast-util-parse-selector": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/hast-util-parse-selector/-/hast-util-parse-selector-4.0.0.tgz",
@@ -2998,6 +3093,21 @@
         "url": "https://opencollective.com/unified"
       }
     },
+    "node_modules/hast-util-to-text": {
+      "version": "4.0.2",
+      "resolved": "https://registry.npmjs.org/hast-util-to-text/-/hast-util-to-text-4.0.2.tgz",
+      "integrity": "sha512-KK6y/BN8lbaq654j7JgBydev7wuNMcID54lkRav1P0CaE1e47P72AWWPiGKXTJU271ooYzcvTAn/Zt0REnvc7A==",
+      "dependencies": {
+        "@types/hast": "^3.0.0",
+        "@types/unist": "^3.0.0",
+        "hast-util-is-element": "^3.0.0",
+        "unist-util-find-after": "^5.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/hast-util-whitespace": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/hast-util-whitespace/-/hast-util-whitespace-3.0.0.tgz",
@@ -3551,6 +3661,24 @@
         "url": "https://opencollective.com/unified"
       }
     },
+    "node_modules/mdast-util-math": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/mdast-util-math/-/mdast-util-math-3.0.0.tgz",
+      "integrity": "sha512-Tl9GBNeG/AhJnQM221bJR2HPvLOSnLE/T9cJI9tlc6zwQk2nPk/4f0cHkOdEixQPC/j8UtKDdITswvLAy1OZ1w==",
+      "dependencies": {
+        "@types/hast": "^3.0.0",
+        "@types/mdast": "^4.0.0",
+        "devlop": "^1.0.0",
+        "longest-streak": "^3.0.0",
+        "mdast-util-from-markdown": "^2.0.0",
+        "mdast-util-to-markdown": "^2.1.0",
+        "unist-util-remove-position": "^5.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/mdast-util-mdx-expression": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/mdast-util-mdx-expression/-/mdast-util-mdx-expression-2.0.1.tgz",
@@ -3882,6 +4010,24 @@
         "url": "https://opencollective.com/unified"
       }
     },
+    "node_modules/micromark-extension-math": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/micromark-extension-math/-/micromark-extension-math-3.1.0.tgz",
+      "integrity": "sha512-lvEqd+fHjATVs+2v/8kg9i5Q0AP2k85H0WUOwpIVvUML8BapsMvh1XAogmQjOCsLpoKRCVQqEkQBB3NhVBcsOg==",
+      "dependencies": {
+        "@types/katex": "^0.16.0",
+        "devlop": "^1.0.0",
+        "katex": "^0.16.0",
+        "micromark-factory-space": "^2.0.0",
+        "micromark-util-character": "^2.0.0",
+        "micromark-util-symbol": "^2.0.0",
+        "micromark-util-types": "^2.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/micromark-factory-destination": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/micromark-factory-destination/-/micromark-factory-destination-2.0.1.tgz",
@@ -4381,6 +4527,17 @@
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+    "node_modules/parse5": {
+      "version": "7.3.0",
+      "resolved": "https://registry.npmjs.org/parse5/-/parse5-7.3.0.tgz",
+      "integrity": "sha512-IInvU7fabl34qmi9gY8XOVxhYyMyuH2xUNpb2q8/Y+7552KlejkRvqvD19nMoUW/uQGGbqNpA6Tufu5FL5BZgw==",
+      "dependencies": {
+        "entities": "^6.0.0"
+      },
+      "funding": {
+        "url": "https://github.com/inikulin/parse5?sponsor=1"
+      }
+    },
     "node_modules/path-data-parser": {
       "version": "0.1.0",
       "resolved": "https://registry.npmjs.org/path-data-parser/-/path-data-parser-0.1.0.tgz",
@@ -4590,6 +4747,24 @@
         "url": "https://github.com/sponsors/wooorm"
       }
     },
+    "node_modules/rehype-katex": {
+      "version": "7.0.1",
+      "resolved": "https://registry.npmjs.org/rehype-katex/-/rehype-katex-7.0.1.tgz",
+      "integrity": "sha512-OiM2wrZ/wuhKkigASodFoo8wimG3H12LWQaH8qSPVJn9apWKFSH3YOCtbKpBorTVw/eI7cuT21XBbvwEswbIOA==",
+      "dependencies": {
+        "@types/hast": "^3.0.0",
+        "@types/katex": "^0.16.0",
+        "hast-util-from-html-isomorphic": "^2.0.0",
+        "hast-util-to-text": "^4.0.0",
+        "katex": "^0.16.0",
+        "unist-util-visit-parents": "^6.0.0",
+        "vfile": "^6.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/remark-gfm": {
       "version": "4.0.1",
       "resolved": "https://registry.npmjs.org/remark-gfm/-/remark-gfm-4.0.1.tgz",
@@ -4607,6 +4782,21 @@
         "url": "https://opencollective.com/unified"
       }
     },
+    "node_modules/remark-math": {
+      "version": "6.0.0",
+      "resolved": "https://registry.npmjs.org/remark-math/-/remark-math-6.0.0.tgz",
+      "integrity": "sha512-MMqgnP74Igy+S3WwnhQ7kqGlEerTETXMvJhrUzDikVZ2/uogJCb+WHUg97hK9/jcfc0dkD73s3LN8zU49cTEtA==",
+      "dependencies": {
+        "@types/mdast": "^4.0.0",
+        "mdast-util-math": "^3.0.0",
+        "micromark-extension-math": "^3.0.0",
+        "unified": "^11.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/remark-parse": {
       "version": "11.0.0",
       "resolved": "https://registry.npmjs.org/remark-parse/-/remark-parse-11.0.0.tgz",
@@ -4911,6 +5101,19 @@
         "url": "https://opencollective.com/unified"
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+    "node_modules/unist-util-find-after": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/unist-util-find-after/-/unist-util-find-after-5.0.0.tgz",
+      "integrity": "sha512-amQa0Ep2m6hE2g72AugUItjbuM8X8cGQnFoHk0pGfrFeT9GZhzN5SW8nRsiGKK7Aif4CrACPENkA6P/Lw6fHGQ==",
+      "dependencies": {
+        "@types/unist": "^3.0.0",
+        "unist-util-is": "^6.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/unist-util-is": {
       "version": "6.0.1",
       "resolved": "https://registry.npmjs.org/unist-util-is/-/unist-util-is-6.0.1.tgz",
@@ -4935,6 +5138,19 @@
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     },
+    "node_modules/unist-util-remove-position": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/unist-util-remove-position/-/unist-util-remove-position-5.0.0.tgz",
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+      "dependencies": {
+        "@types/unist": "^3.0.0",
+        "unist-util-visit": "^5.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/unist-util-stringify-position": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/unist-util-stringify-position/-/unist-util-stringify-position-4.0.0.tgz",
@@ -5038,6 +5254,19 @@
         "url": "https://opencollective.com/unified"
       }
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+    "node_modules/vfile-location": {
+      "version": "5.0.3",
+      "resolved": "https://registry.npmjs.org/vfile-location/-/vfile-location-5.0.3.tgz",
+      "integrity": "sha512-5yXvWDEgqeiYiBe1lbxYF7UMAIm/IcopxMHrMQDq3nvKcjPKIhZklUKL+AE7J7uApI4kwe2snsK+eI6UTj9EHg==",
+      "dependencies": {
+        "@types/unist": "^3.0.0",
+        "vfile": "^6.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/vfile-message": {
       "version": "4.0.3",
       "resolved": "https://registry.npmjs.org/vfile-message/-/vfile-message-4.0.3.tgz",
@@ -5153,6 +5382,15 @@
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+    "node_modules/web-namespaces": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/web-namespaces/-/web-namespaces-2.0.1.tgz",
+      "integrity": "sha512-bKr1DkiNa2krS7qxNtdrtHAmzuYGFQLiQ13TsorsdT6ULTkPLKuu5+GsFpDlg6JFjUTwX2DyhMPG2be8uPrqsQ==",
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
+    },
     "node_modules/which": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/which/-/which-2.0.2.tgz",

ui/package.json

@@ -16,7 +16,9 @@
     "react-dom": "^19.2.4",
     "react-markdown": "^10.1.0",
     "react-syntax-highlighter": "^16.1.1",
-    "remark-gfm": "^4.0.1"
+    "rehype-katex": "^7.0.1",
+    "remark-gfm": "^4.0.1",
+    "remark-math": "^6.0.0"
   },
   "devDependencies": {
     "@eslint/js": "^9.39.4",

ui/src/components/Message.jsx

@@ -1,6 +1,9 @@
 import { useState, useCallback, Suspense, lazy, forwardRef } from "react";
 import ReactMarkdown from "react-markdown";
 import remarkGfm from "remark-gfm";
+import remarkMath from "remark-math";
+import rehypeKatex from "rehype-katex";
+import "katex/dist/katex.min.css";
 import { Prism as SyntaxHighlighter } from "react-syntax-highlighter";
 import { oneDark } from "react-syntax-highlighter/dist/esm/styles/prism";
 import SourceCard from "./SourceCard";
@@ -399,7 +402,7 @@ const Message = forwardRef(function Message({ msg, onDiagramThis, onRetry, showR
 
             {/* Answer bubble */}
             <div className="bubble" style={{ position: "relative", display: msg.rateLimited ? "none" : undefined }}>
-              <ReactMarkdown components={mdComponents} remarkPlugins={[remarkGfm]}>
+              <ReactMarkdown components={mdComponents} remarkPlugins={[remarkGfm, remarkMath]} rehypePlugins={[rehypeKatex]}>
                 {msg.content || " "}
               </ReactMarkdown>
               {/* Show cursor whenever streaming, not just when no tool active */}