Add remark-gfm: render markdown tables properly

Without remark-gfm, react-markdown doesn't parse GFM tables — they
render as raw pipe-separated text. Added the plugin and basic table
styles (bordered cells, alternating row bg, header highlight).

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

ui/package-lock.json

@@ -13,7 +13,8 @@
         "react": "^19.2.4",
         "react-dom": "^19.2.4",
         "react-markdown": "^10.1.0",
-        "react-syntax-highlighter": "^16.1.1"
+        "react-syntax-highlighter": "^16.1.1",
+        "remark-gfm": "^4.0.1"
       },
       "devDependencies": {
         "@eslint/js": "^9.39.4",
@@ -3501,6 +3502,15 @@
         "yallist": "^3.0.2"
       }
     },
+    "node_modules/markdown-table": {
+      "version": "3.0.4",
+      "resolved": "https://registry.npmjs.org/markdown-table/-/markdown-table-3.0.4.tgz",
+      "integrity": "sha512-wiYz4+JrLyb/DqW2hkFJxP7Vd7JuTDm77fvbM8VfEQdmSMqcImWeeRbHwZjBjIFki/VaMK2BhFi7oUUZeM5bqw==",
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
+    },
     "node_modules/marked": {
       "version": "16.4.2",
       "resolved": "https://registry.npmjs.org/marked/-/marked-16.4.2.tgz",
@@ -3512,6 +3522,32 @@
         "node": ">= 20"
       }
     },
+    "node_modules/mdast-util-find-and-replace": {
+      "version": "3.0.2",
+      "resolved": "https://registry.npmjs.org/mdast-util-find-and-replace/-/mdast-util-find-and-replace-3.0.2.tgz",
+      "integrity": "sha512-Tmd1Vg/m3Xz43afeNxDIhWRtFZgM2VLyaf4vSTYwudTyeuTneoL3qtWMA5jeLyz/O1vDJmmV4QuScFCA2tBPwg==",
+      "dependencies": {
+        "@types/mdast": "^4.0.0",
+        "escape-string-regexp": "^5.0.0",
+        "unist-util-is": "^6.0.0",
+        "unist-util-visit-parents": "^6.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/mdast-util-find-and-replace/node_modules/escape-string-regexp": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/escape-string-regexp/-/escape-string-regexp-5.0.0.tgz",
+      "integrity": "sha512-/veY75JbMK4j1yjvuUxuVsiS/hr/4iHs9FTT6cgTexxdE0Ly/glccBAkloH/DofkjRbZU3bnoj38mOmhkZ0lHw==",
+      "engines": {
+        "node": ">=12"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/mdast-util-from-markdown": {
       "version": "2.0.3",
       "resolved": "https://registry.npmjs.org/mdast-util-from-markdown/-/mdast-util-from-markdown-2.0.3.tgz",
@@ -3535,6 +3571,101 @@
         "url": "https://opencollective.com/unified"
       }
     },
+    "node_modules/mdast-util-gfm": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/mdast-util-gfm/-/mdast-util-gfm-3.1.0.tgz",
+      "integrity": "sha512-0ulfdQOM3ysHhCJ1p06l0b0VKlhU0wuQs3thxZQagjcjPrlFRqY215uZGHHJan9GEAXd9MbfPjFJz+qMkVR6zQ==",
+      "dependencies": {
+        "mdast-util-from-markdown": "^2.0.0",
+        "mdast-util-gfm-autolink-literal": "^2.0.0",
+        "mdast-util-gfm-footnote": "^2.0.0",
+        "mdast-util-gfm-strikethrough": "^2.0.0",
+        "mdast-util-gfm-table": "^2.0.0",
+        "mdast-util-gfm-task-list-item": "^2.0.0",
+        "mdast-util-to-markdown": "^2.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/mdast-util-gfm-autolink-literal": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/mdast-util-gfm-autolink-literal/-/mdast-util-gfm-autolink-literal-2.0.1.tgz",
+      "integrity": "sha512-5HVP2MKaP6L+G6YaxPNjuL0BPrq9orG3TsrZ9YXbA3vDw/ACI4MEsnoDpn6ZNm7GnZgtAcONJyPhOP8tNJQavQ==",
+      "dependencies": {
+        "@types/mdast": "^4.0.0",
+        "ccount": "^2.0.0",
+        "devlop": "^1.0.0",
+        "mdast-util-find-and-replace": "^3.0.0",
+        "micromark-util-character": "^2.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/mdast-util-gfm-footnote": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/mdast-util-gfm-footnote/-/mdast-util-gfm-footnote-2.1.0.tgz",
+      "integrity": "sha512-sqpDWlsHn7Ac9GNZQMeUzPQSMzR6Wv0WKRNvQRg0KqHh02fpTz69Qc1QSseNX29bhz1ROIyNyxExfawVKTm1GQ==",
+      "dependencies": {
+        "@types/mdast": "^4.0.0",
+        "devlop": "^1.1.0",
+        "mdast-util-from-markdown": "^2.0.0",
+        "mdast-util-to-markdown": "^2.0.0",
+        "micromark-util-normalize-identifier": "^2.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/mdast-util-gfm-strikethrough": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/mdast-util-gfm-strikethrough/-/mdast-util-gfm-strikethrough-2.0.0.tgz",
+      "integrity": "sha512-mKKb915TF+OC5ptj5bJ7WFRPdYtuHv0yTRxK2tJvi+BDqbkiG7h7u/9SI89nRAYcmap2xHQL9D+QG/6wSrTtXg==",
+      "dependencies": {
+        "@types/mdast": "^4.0.0",
+        "mdast-util-from-markdown": "^2.0.0",
+        "mdast-util-to-markdown": "^2.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/mdast-util-gfm-table": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/mdast-util-gfm-table/-/mdast-util-gfm-table-2.0.0.tgz",
+      "integrity": "sha512-78UEvebzz/rJIxLvE7ZtDd/vIQ0RHv+3Mh5DR96p7cS7HsBhYIICDBCu8csTNWNO6tBWfqXPWekRuj2FNOGOZg==",
+      "dependencies": {
+        "@types/mdast": "^4.0.0",
+        "devlop": "^1.0.0",
+        "markdown-table": "^3.0.0",
+        "mdast-util-from-markdown": "^2.0.0",
+        "mdast-util-to-markdown": "^2.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/mdast-util-gfm-task-list-item": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/mdast-util-gfm-task-list-item/-/mdast-util-gfm-task-list-item-2.0.0.tgz",
+      "integrity": "sha512-IrtvNvjxC1o06taBAVJznEnkiHxLFTzgonUdy8hzFVeDun0uTjxxrRGVaNFqkU1wJR3RBPEfsxmU6jDWPofrTQ==",
+      "dependencies": {
+        "@types/mdast": "^4.0.0",
+        "devlop": "^1.0.0",
+        "mdast-util-from-markdown": "^2.0.0",
+        "mdast-util-to-markdown": "^2.0.0"
+      },
+      "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",
@@ -3752,6 +3883,120 @@
         "micromark-util-types": "^2.0.0"
       }
     },
+    "node_modules/micromark-extension-gfm": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/micromark-extension-gfm/-/micromark-extension-gfm-3.0.0.tgz",
+      "integrity": "sha512-vsKArQsicm7t0z2GugkCKtZehqUm31oeGBV/KVSorWSy8ZlNAv7ytjFhvaryUiCUJYqs+NoE6AFhpQvBTM6Q4w==",
+      "dependencies": {
+        "micromark-extension-gfm-autolink-literal": "^2.0.0",
+        "micromark-extension-gfm-footnote": "^2.0.0",
+        "micromark-extension-gfm-strikethrough": "^2.0.0",
+        "micromark-extension-gfm-table": "^2.0.0",
+        "micromark-extension-gfm-tagfilter": "^2.0.0",
+        "micromark-extension-gfm-task-list-item": "^2.0.0",
+        "micromark-util-combine-extensions": "^2.0.0",
+        "micromark-util-types": "^2.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/micromark-extension-gfm-autolink-literal": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/micromark-extension-gfm-autolink-literal/-/micromark-extension-gfm-autolink-literal-2.1.0.tgz",
+      "integrity": "sha512-oOg7knzhicgQ3t4QCjCWgTmfNhvQbDDnJeVu9v81r7NltNCVmhPy1fJRX27pISafdjL+SVc4d3l48Gb6pbRypw==",
+      "dependencies": {
+        "micromark-util-character": "^2.0.0",
+        "micromark-util-sanitize-uri": "^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-extension-gfm-footnote": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/micromark-extension-gfm-footnote/-/micromark-extension-gfm-footnote-2.1.0.tgz",
+      "integrity": "sha512-/yPhxI1ntnDNsiHtzLKYnE3vf9JZ6cAisqVDauhp4CEHxlb4uoOTxOCJ+9s51bIB8U1N1FJ1RXOKTIlD5B/gqw==",
+      "dependencies": {
+        "devlop": "^1.0.0",
+        "micromark-core-commonmark": "^2.0.0",
+        "micromark-factory-space": "^2.0.0",
+        "micromark-util-character": "^2.0.0",
+        "micromark-util-normalize-identifier": "^2.0.0",
+        "micromark-util-sanitize-uri": "^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-extension-gfm-strikethrough": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/micromark-extension-gfm-strikethrough/-/micromark-extension-gfm-strikethrough-2.1.0.tgz",
+      "integrity": "sha512-ADVjpOOkjz1hhkZLlBiYA9cR2Anf8F4HqZUO6e5eDcPQd0Txw5fxLzzxnEkSkfnD0wziSGiv7sYhk/ktvbf1uw==",
+      "dependencies": {
+        "devlop": "^1.0.0",
+        "micromark-util-chunked": "^2.0.0",
+        "micromark-util-classify-character": "^2.0.0",
+        "micromark-util-resolve-all": "^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-extension-gfm-table": {
+      "version": "2.1.1",
+      "resolved": "https://registry.npmjs.org/micromark-extension-gfm-table/-/micromark-extension-gfm-table-2.1.1.tgz",
+      "integrity": "sha512-t2OU/dXXioARrC6yWfJ4hqB7rct14e8f7m0cbI5hUmDyyIlwv5vEtooptH8INkbLzOatzKuVbQmAYcbWoyz6Dg==",
+      "dependencies": {
+        "devlop": "^1.0.0",
+        "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-extension-gfm-tagfilter": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/micromark-extension-gfm-tagfilter/-/micromark-extension-gfm-tagfilter-2.0.0.tgz",
+      "integrity": "sha512-xHlTOmuCSotIA8TW1mDIM6X2O1SiX5P9IuDtqGonFhEK0qgRI4yeC6vMxEV2dgyr2TiD+2PQ10o+cOhdVAcwfg==",
+      "dependencies": {
+        "micromark-util-types": "^2.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/micromark-extension-gfm-task-list-item": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/micromark-extension-gfm-task-list-item/-/micromark-extension-gfm-task-list-item-2.1.0.tgz",
+      "integrity": "sha512-qIBZhqxqI6fjLDYFTBIa4eivDMnP+OZqsNwmQ3xNLE4Cxwc+zfQEfbs6tzAo2Hjq+bh6q5F+Z8/cksrLFYWQQw==",
+      "dependencies": {
+        "devlop": "^1.0.0",
+        "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",
@@ -4499,6 +4744,23 @@
         "url": "https://github.com/sponsors/wooorm"
       }
     },
+    "node_modules/remark-gfm": {
+      "version": "4.0.1",
+      "resolved": "https://registry.npmjs.org/remark-gfm/-/remark-gfm-4.0.1.tgz",
+      "integrity": "sha512-1quofZ2RQ9EWdeN34S79+KExV1764+wCUGop5CPL1WGdD0ocPpu91lzPGbwWMECpEpd42kJGQwzRfyov9j4yNg==",
+      "dependencies": {
+        "@types/mdast": "^4.0.0",
+        "mdast-util-gfm": "^3.0.0",
+        "micromark-extension-gfm": "^3.0.0",
+        "remark-parse": "^11.0.0",
+        "remark-stringify": "^11.0.0",
+        "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",
@@ -4530,6 +4792,20 @@
         "url": "https://opencollective.com/unified"
       }
     },
+    "node_modules/remark-stringify": {
+      "version": "11.0.0",
+      "resolved": "https://registry.npmjs.org/remark-stringify/-/remark-stringify-11.0.0.tgz",
+      "integrity": "sha512-1OSmLd3awB/t8qdoEOMazZkNsfVTeY4fTsgzcQFdXNq8ToTN4ZGwrMnlda4K6smTFKD+GRV6O48i6Z4iKgPPpw==",
+      "dependencies": {
+        "@types/mdast": "^4.0.0",
+        "mdast-util-to-markdown": "^2.0.0",
+        "unified": "^11.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/resolve-from": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/resolve-from/-/resolve-from-4.0.0.tgz",

ui/package.json

@@ -15,7 +15,8 @@
     "react": "^19.2.4",
     "react-dom": "^19.2.4",
     "react-markdown": "^10.1.0",
-    "react-syntax-highlighter": "^16.1.1"
+    "react-syntax-highlighter": "^16.1.1",
+    "remark-gfm": "^4.0.1"
   },
   "devDependencies": {
     "@eslint/js": "^9.39.4",

ui/src/components/Message.jsx

@@ -1,5 +1,6 @@
 import { useState, useCallback, Suspense, lazy, forwardRef } from "react";
 import ReactMarkdown from "react-markdown";
+import remarkGfm from "remark-gfm";
 import { Prism as SyntaxHighlighter } from "react-syntax-highlighter";
 import { oneDark } from "react-syntax-highlighter/dist/esm/styles/prism";
 import SourceCard from "./SourceCard";
@@ -394,7 +395,7 @@ 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}>
+              <ReactMarkdown components={mdComponents} remarkPlugins={[remarkGfm]}>
                 {msg.content || " "}
               </ReactMarkdown>
               {/* Show cursor whenever streaming, not just when no tool active */}

ui/src/index.css

@@ -706,6 +706,28 @@ textarea:focus-visible {
     0 4px 12px rgba(212, 132, 90, 0.30);
 }
 
+/* ── GFM table styles (remark-gfm renders <table> inside .bubble) ── */
+.bubble table {
+  border-collapse: collapse;
+  width: 100%;
+  font-size: 13px;
+  margin: 12px 0;
+}
+.bubble th, .bubble td {
+  border: 1px solid var(--border);
+  padding: 6px 10px;
+  text-align: left;
+  line-height: 1.5;
+}
+.bubble th {
+  background: rgba(237,228,206,0.06);
+  font-weight: 600;
+  color: var(--text);
+}
+.bubble tr:nth-child(even) td {
+  background: rgba(237,228,206,0.03);
+}
+
 /* ── Message bubbles ──────────────────────────────────────── */
 .bubble {
   padding: 14px 18px;