fix: resolve TipTap v3 collaboration crash

- Replace @tiptap /extension-collaboration-cursor v2 with custom
CollaborationCursorV3 using yCursorPlugin from @tiptap /y-tiptap
(same ySyncPluginKey as Collaboration v3)
- Simplify CollaborationUndo to read UndoManager from Collaboration v3's
yUndoPlugin instead of creating its own
- Fix BubbleMenu import: @tiptap /react/menus (v3 API change)
- Install @floating-ui/dom, remove y-prosemirror and .npmrc
- Fix backend Image import to named export

Made-with: Cursor

backend/src/publisher/extensions.ts

@@ -11,7 +11,7 @@ import { Node, mergeAttributes, type Extensions } from "@tiptap/core";
 import StarterKit from "@tiptap/starter-kit";
 import CodeBlockLowlight from "@tiptap/extension-code-block-lowlight";
 import Mathematics from "@tiptap/extension-mathematics";
-import Image from "@tiptap/extension-image";
+import { Image } from "@tiptap/extension-image";
 import { Table } from "@tiptap/extension-table";
 import { TableRow } from "@tiptap/extension-table-row";
 import { TableCell } from "@tiptap/extension-table-cell";
@@ -305,6 +305,7 @@ export function getServerExtensions(): Extensions {
   return [
     StarterKit.configure({
       codeBlock: false,
+      undoRedo: false,
       link: { openOnClick: false },
     } as any),
     CodeBlockLowlight.configure({ lowlight }),

frontend/.npmrc

@@ -1 +0,0 @@
-legacy-peer-deps=true

frontend/package-lock.json

@@ -11,13 +11,12 @@
         "@ai-sdk/react": "^3.0.160",
         "@emotion/react": "^11.14.0",
         "@emotion/styled": "^11.14.1",
+        "@floating-ui/dom": "^1.7.6",
         "@mui/icons-material": "^9.0.0",
         "@mui/material": "^9.0.0",
         "@tiptap/core": "^3.22.3",
-        "@tiptap/extension-bubble-menu": "^3.22.3",
         "@tiptap/extension-code-block-lowlight": "^3.22.3",
         "@tiptap/extension-collaboration": "^3.22.3",
-        "@tiptap/extension-collaboration-cursor": "^2.26.2",
         "@tiptap/extension-image": "^3.22.3",
         "@tiptap/extension-link": "^3.22.3",
         "@tiptap/extension-mathematics": "^3.22.3",
@@ -39,7 +38,6 @@
         "react": "^18.3.0",
         "react-dom": "^18.3.0",
         "tippy.js": "^6.3.7",
-        "y-prosemirror": "^1.2.0",
         "y-websocket": "^2.0.0",
         "yjs": "^13.6.0",
         "zod": "^4.3.6"
@@ -145,6 +143,7 @@
       "integrity": "sha512-CGOfOJqWjg2qW/Mb6zNsDm+u5vFQ8DxXfbM09z69p5Z6+mE1ikP2jUXw+j42Pf1XTYED2Rni5f95npYeuwMDQA==",
       "dev": true,
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "@babel/code-frame": "^7.29.0",
         "@babel/generator": "^7.29.0",
@@ -461,6 +460,7 @@
       "resolved": "https://registry.npmjs.org/@emotion/react/-/react-11.14.0.tgz",
       "integrity": "sha512-O000MLDBDdk/EohJPFUqvnp4qnHeYkVP5B0xEG0D/L7cOKP9kefu2DXn8dj74cQfsEzUqh+sr1RzFqiL1o+PpA==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "@babel/runtime": "^7.18.3",
         "@emotion/babel-plugin": "^11.13.5",
@@ -504,6 +504,7 @@
       "resolved": "https://registry.npmjs.org/@emotion/styled/-/styled-11.14.1.tgz",
       "integrity": "sha512-qEEJt42DuToa3gurlH4Qqc1kVpNq8wO8cJtDzU46TjlzWjDlsVyevtYCRijVq3SrHsROS+gVQ8Fnea108GnKzw==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "@babel/runtime": "^7.18.3",
         "@emotion/babel-plugin": "^11.13.5",
@@ -1005,6 +1006,7 @@
       "resolved": "https://registry.npmjs.org/@floating-ui/dom/-/dom-1.7.6.tgz",
       "integrity": "sha512-9gZSAI5XM36880PPMm//9dfiEngYoC6Am2izES1FF406YFsjvyBMmeJ2g4SAju3xWwtuynNRFL2s9hgxpLI5SQ==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "@floating-ui/core": "^1.7.5",
         "@floating-ui/utils": "^0.2.11"
@@ -1103,6 +1105,7 @@
       "resolved": "https://registry.npmjs.org/@mui/material/-/material-9.0.0.tgz",
       "integrity": "sha512-+VP/oQCDhDR87NQQgXnNBG8dwy6GNuQLnenS1pZvkbn2dKFSxRSRMybTpH9xUxXP+316mlYDy5CSbYtusnCWtw==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "@babel/runtime": "^7.29.2",
         "@mui/core-downloads-tracker": "^9.0.0",
@@ -1688,6 +1691,7 @@
       "resolved": "https://registry.npmjs.org/@tiptap/core/-/core-3.22.3.tgz",
       "integrity": "sha512-Dv9MKK5BDWCF0N2l6/Pxv3JNCce2kwuWf2cKMBc2bEetx0Pn6o7zlFmSxMvYK4UtG1Tw9Yg/ZHi6QOFWK0Zm9Q==",
       "license": "MIT",
+      "peer": true,
       "funding": {
         "type": "github",
         "url": "https://github.com/sponsors/ueberdosis"
@@ -1727,6 +1731,7 @@
       "resolved": "https://registry.npmjs.org/@tiptap/extension-bubble-menu/-/extension-bubble-menu-3.22.3.tgz",
       "integrity": "sha512-Y6zQjh0ypDg32HWgICEvmPSKjGLr39k3aDxxt/H0uQEZSfw4smT0hxUyyyjVjx68C6t6MTnwdfz0hPI5lL68vQ==",
       "license": "MIT",
+      "optional": true,
       "dependencies": {
         "@floating-ui/dom": "^1.0.0"
       },
@@ -1770,6 +1775,7 @@
       "resolved": "https://registry.npmjs.org/@tiptap/extension-code-block/-/extension-code-block-3.22.3.tgz",
       "integrity": "sha512-RiQtEjDAPrHpdo6sw6b7fOw/PijqgFIsozKKkGcSeBgWHQuFg7q9OxJTj+l0e60rVwSu/5gmKEEobzM9bX+t2Q==",
       "license": "MIT",
+      "peer": true,
       "funding": {
         "type": "github",
         "url": "https://github.com/sponsors/ueberdosis"
@@ -1812,20 +1818,6 @@
         "yjs": "^13"
       }
     },
-    "node_modules/@tiptap/extension-collaboration-cursor": {
-      "version": "2.26.2",
-      "resolved": "https://registry.npmjs.org/@tiptap/extension-collaboration-cursor/-/extension-collaboration-cursor-2.26.2.tgz",
-      "integrity": "sha512-FdRb27mZ5Kr18hN6cbfBj1e9F0DOoHB1Gv3IYeic+g4h1C9BjDVMN0+JRBQc+4lamNA8TsHO0oKWRwaPe4sSlA==",
-      "license": "MIT",
-      "funding": {
-        "type": "github",
-        "url": "https://github.com/sponsors/ueberdosis"
-      },
-      "peerDependencies": {
-        "@tiptap/core": "^2.7.0",
-        "y-prosemirror": "^1.2.11"
-      }
-    },
     "node_modules/@tiptap/extension-document": {
       "version": "3.22.3",
       "resolved": "https://registry.npmjs.org/@tiptap/extension-document/-/extension-document-3.22.3.tgz",
@@ -1969,6 +1961,7 @@
       "resolved": "https://registry.npmjs.org/@tiptap/extension-list/-/extension-list-3.22.3.tgz",
       "integrity": "sha512-rqvv/dtqwbX+8KnPv0eMYp6PnBcuhPMol5cv1GlS8Nq/Cxt68EWGUHBuTFesw+hdnRQLmKwzoO1DlRn7PhxYRQ==",
       "license": "MIT",
+      "peer": true,
       "funding": {
         "type": "github",
         "url": "https://github.com/sponsors/ueberdosis"
@@ -2076,6 +2069,7 @@
       "resolved": "https://registry.npmjs.org/@tiptap/extension-table/-/extension-table-3.22.3.tgz",
       "integrity": "sha512-inbQSusJad7H0T++L1APg/anfL5d15cNGp2YG3vwo6TQr71nn2c9pepvmz3xuAIt8eygZDRba+4GT/COP1f9QA==",
       "license": "MIT",
+      "peer": true,
       "funding": {
         "type": "github",
         "url": "https://github.com/sponsors/ueberdosis"
@@ -2155,6 +2149,7 @@
       "resolved": "https://registry.npmjs.org/@tiptap/extensions/-/extensions-3.22.3.tgz",
       "integrity": "sha512-s5eiMq0m5N6N+W7dU6rd60KgZyyCD7FvtPNNswISfPr12EQwJBfbjWwTqd0UKNzA4fNrhQEERXnzORkykttPeA==",
       "license": "MIT",
+      "peer": true,
       "funding": {
         "type": "github",
         "url": "https://github.com/sponsors/ueberdosis"
@@ -2169,6 +2164,7 @@
       "resolved": "https://registry.npmjs.org/@tiptap/pm/-/pm-3.22.3.tgz",
       "integrity": "sha512-NjfWjZuvrqmpICT+GZWNIjtOdhPyqFKDMtQy7tsQ5rErM9L2ZQdy/+T/BKSO1JdTeBhdg9OP+0yfsqoYp2aT6A==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "prosemirror-changeset": "^2.3.0",
         "prosemirror-collab": "^1.3.1",
@@ -2276,6 +2272,7 @@
       "resolved": "https://registry.npmjs.org/@tiptap/y-tiptap/-/y-tiptap-3.0.3.tgz",
       "integrity": "sha512-8UvuV4lTisCE9cMTc/X8kRyTn9edUO7Kball0I6wb17VwZSjNDfh/YKtP4O5vcPawEzFHQIvZGq/k1h37kAf0w==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "lib0": "^0.2.100"
       },
@@ -2396,8 +2393,8 @@
       "version": "18.3.28",
       "resolved": "https://registry.npmjs.org/@types/react/-/react-18.3.28.tgz",
       "integrity": "sha512-z9VXpC7MWrhfWipitjNdgCauoMLRdIILQsAEV+ZesIzBq/oUlxk0m3ApZuMFCXdnS4U7KrI+l3WRUEGQ8K1QKw==",
-      "dev": true,
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "@types/prop-types": "*",
         "csstype": "^3.2.2"
@@ -2407,8 +2404,8 @@
       "version": "18.3.7",
       "resolved": "https://registry.npmjs.org/@types/react-dom/-/react-dom-18.3.7.tgz",
       "integrity": "sha512-MEe3UeoENYVFXzoXEWsvcpg6ZvlrFNlOQ7EOsvhI3CfAXwzPfO8Qwuxd40nepsYKqyyVQnTdEfv68q91yLcKrQ==",
-      "dev": true,
       "license": "MIT",
+      "peer": true,
       "peerDependencies": {
         "@types/react": "^18.0.0"
       }
@@ -2582,6 +2579,7 @@
         }
       ],
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "baseline-browser-mapping": "^2.10.12",
         "caniuse-lite": "^1.0.30001782",
@@ -2691,6 +2689,15 @@
         "node": ">=10"
       }
     },
+    "node_modules/cosmiconfig/node_modules/yaml": {
+      "version": "1.10.3",
+      "resolved": "https://registry.npmjs.org/yaml/-/yaml-1.10.3.tgz",
+      "integrity": "sha512-vIYeF1u3CjlhAFekPPAk2h/Kv4T3mAkMox5OymRiJQB0spDP10LHvt+K7G9Ny6NuuMAb25/6n1qyUjAcGNf/AA==",
+      "license": "ISC",
+      "engines": {
+        "node": ">= 6"
+      }
+    },
     "node_modules/crelt": {
       "version": "1.0.6",
       "resolved": "https://registry.npmjs.org/crelt/-/crelt-1.0.6.tgz",
@@ -2991,6 +2998,7 @@
       "resolved": "https://registry.npmjs.org/highlight.js/-/highlight.js-11.11.1.tgz",
       "integrity": "sha512-Xwwo44whKBVCYoliBQwaPvtd/2tYFkRQtXDWj1nackaV2JPXx3L0+Jvd8/qCJ2p+ML0/XVkJ2q+Mr+UVdpJK5w==",
       "license": "BSD-3-Clause",
+      "peer": true,
       "engines": {
         "node": ">=12.0.0"
       }
@@ -3144,6 +3152,7 @@
         "https://github.com/sponsors/katex"
       ],
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "commander": "^8.3.0"
       },
@@ -3366,6 +3375,7 @@
       "resolved": "https://registry.npmjs.org/lowlight/-/lowlight-3.3.0.tgz",
       "integrity": "sha512-0JNhgFoPvP6U6lE/UdVsSq99tn6DhjjpAj5MxG49ewd2mOBVtwWYIT8ClyABhq198aXXODMU6Ox8DrGy/CpTZQ==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "@types/hast": "^3.0.0",
         "devlop": "^1.0.0",
@@ -3539,6 +3549,7 @@
       "integrity": "sha512-QP88BAKvMam/3NxH6vj2o21R6MjxZUAd6nlwAS/pnGvN9IVLocLHxGYIzFhg6fUQ+5th6P4dv4eW9jX3DSIj7A==",
       "dev": true,
       "license": "MIT",
+      "peer": true,
       "engines": {
         "node": ">=12"
       },
@@ -3704,6 +3715,7 @@
       "resolved": "https://registry.npmjs.org/prosemirror-model/-/prosemirror-model-1.25.4.tgz",
       "integrity": "sha512-PIM7E43PBxKce8OQeezAs9j4TP+5yDpZVbuurd1h5phUxEKIu+G2a+EUZzIC5nS1mJktDJWzbqS23n1tsAf5QA==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "orderedmap": "^2.0.0"
       }
@@ -3733,6 +3745,7 @@
       "resolved": "https://registry.npmjs.org/prosemirror-state/-/prosemirror-state-1.4.4.tgz",
       "integrity": "sha512-6jiYHH2CIGbCfnxdHbXZ12gySFY/fz/ulZE333G6bPqIZ4F+TXo9ifiR86nAHpWnfoNjOb3o5ESi7J8Uz1jXHw==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "prosemirror-model": "^1.0.0",
         "prosemirror-transform": "^1.0.0",
@@ -3781,6 +3794,7 @@
       "resolved": "https://registry.npmjs.org/prosemirror-view/-/prosemirror-view-1.41.8.tgz",
       "integrity": "sha512-TnKDdohEatgyZNGCDWIdccOHXhYloJwbwU+phw/a23KBvJIR9lWQWW7WHHK3vBdOLDNuF7TaX98GObUZOWkOnA==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "prosemirror-model": "^1.20.0",
         "prosemirror-state": "^1.0.0",
@@ -3808,6 +3822,7 @@
       "resolved": "https://registry.npmjs.org/react/-/react-18.3.1.tgz",
       "integrity": "sha512-wS+hAgJShR0KhEvPJArfuPVN1+Hz1t0Y6n5jLrGQbkb4urgPE/0Rve+1kMB1v/oWgHgm4WIcV+i7F2pTVj+2iQ==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "loose-envify": "^1.1.0"
       },
@@ -3820,6 +3835,7 @@
       "resolved": "https://registry.npmjs.org/react-dom/-/react-dom-18.3.1.tgz",
       "integrity": "sha512-5m4nQKp+rZRb09LNH59GM4BxTh9251/ylbKIbpe7TpGxfJ+9kv6BLkLBXIjjspbgbnIBNqlI23tRnTWT0snUIw==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "loose-envify": "^1.1.0",
         "scheduler": "^0.23.2"
@@ -4153,6 +4169,7 @@
       "integrity": "sha512-2N/55r4JDJ4gdrCvGgINMy+HH3iRpNIz8K6SFwVsA+JbQScLiC+clmAxBgwiSPgcG9U15QmvqCGWzMbqda5zGQ==",
       "dev": true,
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "esbuild": "^0.25.0",
         "fdir": "^6.4.4",
@@ -4266,35 +4283,12 @@
         "yjs": "^13.0.0"
       }
     },
-    "node_modules/y-prosemirror": {
-      "version": "1.3.7",
-      "resolved": "https://registry.npmjs.org/y-prosemirror/-/y-prosemirror-1.3.7.tgz",
-      "integrity": "sha512-NpM99WSdD4Fx4if5xOMDpPtU3oAmTSjlzh5U4353ABbRHl1HtAFUx6HlebLZfyFxXN9jzKMDkVbcRjqOZVkYQg==",
-      "license": "MIT",
-      "dependencies": {
-        "lib0": "^0.2.109"
-      },
-      "engines": {
-        "node": ">=16.0.0",
-        "npm": ">=8.0.0"
-      },
-      "funding": {
-        "type": "GitHub Sponsors ❤",
-        "url": "https://github.com/sponsors/dmonad"
-      },
-      "peerDependencies": {
-        "prosemirror-model": "^1.7.1",
-        "prosemirror-state": "^1.2.3",
-        "prosemirror-view": "^1.9.10",
-        "y-protocols": "^1.0.1",
-        "yjs": "^13.5.38"
-      }
-    },
     "node_modules/y-protocols": {
       "version": "1.0.7",
       "resolved": "https://registry.npmjs.org/y-protocols/-/y-protocols-1.0.7.tgz",
       "integrity": "sha512-YSVsLoXxO67J6eE/nV4AtFtT3QEotZf5sK5BHxFBXso7VDUT3Tx07IfA6hsu5Q5OmBdMkQVmFZ9QOA7fikWvnw==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "lib0": "^0.2.85"
       },
@@ -4347,20 +4341,12 @@
       "dev": true,
       "license": "ISC"
     },
-    "node_modules/yaml": {
-      "version": "1.10.3",
-      "resolved": "https://registry.npmjs.org/yaml/-/yaml-1.10.3.tgz",
-      "integrity": "sha512-vIYeF1u3CjlhAFekPPAk2h/Kv4T3mAkMox5OymRiJQB0spDP10LHvt+K7G9Ny6NuuMAb25/6n1qyUjAcGNf/AA==",
-      "license": "ISC",
-      "engines": {
-        "node": ">= 6"
-      }
-    },
     "node_modules/yjs": {
       "version": "13.6.30",
       "resolved": "https://registry.npmjs.org/yjs/-/yjs-13.6.30.tgz",
       "integrity": "sha512-vv/9h42eCMC81ZHDFswuu/MKzkl/vyq1BhaNGfHyOonwlG4CJbQF4oiBBJPvfdeCt/PlVDWh7Nov9D34YY09uQ==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "lib0": "^0.2.99"
       },
@@ -4378,6 +4364,7 @@
       "resolved": "https://registry.npmjs.org/zod/-/zod-4.3.6.tgz",
       "integrity": "sha512-rftlrkhHZOcjDwkGlnUtZZkvaPHCsDATp4pGpuOOMDaTdDDXF91wuVDJoWoPsKX/3YPQ5fHuF3STjcYyKr+Qhg==",
       "license": "MIT",
+      "peer": true,
       "funding": {
         "url": "https://github.com/sponsors/colinhacks"
       }

frontend/package.json

@@ -12,13 +12,12 @@
     "@ai-sdk/react": "^3.0.160",
     "@emotion/react": "^11.14.0",
     "@emotion/styled": "^11.14.1",
+    "@floating-ui/dom": "^1.7.6",
     "@mui/icons-material": "^9.0.0",
     "@mui/material": "^9.0.0",
     "@tiptap/core": "^3.22.3",
-    "@tiptap/extension-bubble-menu": "^3.22.3",
     "@tiptap/extension-code-block-lowlight": "^3.22.3",
     "@tiptap/extension-collaboration": "^3.22.3",
-    "@tiptap/extension-collaboration-cursor": "^2.26.2",
     "@tiptap/extension-image": "^3.22.3",
     "@tiptap/extension-link": "^3.22.3",
     "@tiptap/extension-mathematics": "^3.22.3",
@@ -40,7 +39,6 @@
     "react": "^18.3.0",
     "react-dom": "^18.3.0",
     "tippy.js": "^6.3.7",
-    "y-prosemirror": "^1.2.0",
     "y-websocket": "^2.0.0",
     "yjs": "^13.6.0",
     "zod": "^4.3.6"

frontend/src/editor/BubbleToolbar.tsx

@@ -1,4 +1,4 @@
-import { BubbleMenu } from "@tiptap/extension-bubble-menu";
+import { BubbleMenu } from "@tiptap/react/menus";
 import type { Editor } from "@tiptap/core";
 import { Box, IconButton, Divider, Tooltip } from "@mui/material";
 import FormatBoldIcon from "@mui/icons-material/FormatBold";
@@ -59,7 +59,7 @@ export function BubbleToolbar({ editor, onAddComment }: BubbleToolbarProps) {
   return (
     <BubbleMenu
       editor={editor}
-      tippyOptions={{ duration: 150, placement: "top" }}
+      options={{ placement: "top", offset: 6 }}
     >
       <Box
         sx={{

frontend/src/editor/Editor.tsx

@@ -2,7 +2,7 @@ import { useEditor, EditorContent } from "@tiptap/react";
 import { Editor as TiptapEditor } from "@tiptap/core";
 import StarterKit from "@tiptap/starter-kit";
 import Collaboration from "@tiptap/extension-collaboration";
-import CollaborationCursor from "@tiptap/extension-collaboration-cursor";
+import { CollaborationCursorV3 } from "./extensions/collaboration-cursor-v3";
 import Placeholder from "@tiptap/extension-placeholder";
 import CodeBlockLowlight from "@tiptap/extension-code-block-lowlight";
 // Link is included in StarterKit v3, configured via StarterKit options
@@ -66,7 +66,6 @@ export function Editor({
   onAddComment,
 }: EditorProps) {
   const ydoc = useMemo(() => new Y.Doc(), []);
-  const fragment = useMemo(() => ydoc.getXmlFragment("default"), [ydoc]);
   const undoManagerCallbackRef = useRef(onUndoManagerReady);
   undoManagerCallbackRef.current = onUndoManagerReady;
 
@@ -163,7 +162,7 @@ export function Editor({
         Collaboration.configure({
           document: ydoc,
         }),
-        CollaborationCursor.configure({
+        CollaborationCursorV3.configure({
           provider,
           user,
         }),
@@ -189,13 +188,12 @@ export function Editor({
         ...COMPONENTS.filter((d) => d.kind === "wrapper").map(createWrapperExtension),
         ...COMPONENTS.filter((d) => d.kind === "atomic").map(createAtomicExtension),
         CollaborationUndo.configure({
-          fragment,
           onUndoManagerReady: (um) => undoManagerCallbackRef.current?.(um),
         }),
         Comment,
       ],
     },
-    [ydoc, provider, fragment],
+    [ydoc, provider],
   );
 
   const seededRef = useRef(false);

frontend/src/editor/extensions/collaboration-cursor-v3.ts

@@ -0,0 +1,80 @@
+import { Extension } from "@tiptap/core";
+import { yCursorPlugin, defaultCursorBuilder, defaultSelectionBuilder } from "@tiptap/y-tiptap";
+
+export interface CollaborationCursorOptions {
+  provider: any;
+  user: { name: string; color: string };
+  render?: (user: { name: string; color: string }) => HTMLElement;
+  selectionRender?: typeof defaultSelectionBuilder;
+}
+
+const awarenessStatesToArray = (states: Map<number, any>) => {
+  return Array.from(states.entries()).map(([key, value]) => ({
+    clientId: key,
+    ...value.user,
+  }));
+};
+
+export const CollaborationCursorV3 = Extension.create<CollaborationCursorOptions>({
+  name: "collaborationCursor",
+  priority: 999,
+
+  addOptions() {
+    return {
+      provider: null,
+      user: { name: "Anonymous", color: "#aaaaaa" },
+      render: (user: { name: string; color: string }) => {
+        const cursor = document.createElement("span");
+        cursor.classList.add("collaboration-cursor__caret");
+        cursor.setAttribute("style", `border-color: ${user.color}`);
+        const label = document.createElement("div");
+        label.classList.add("collaboration-cursor__label");
+        label.setAttribute("style", `background-color: ${user.color}`);
+        label.insertBefore(document.createTextNode(user.name), null);
+        cursor.insertBefore(label, null);
+        return cursor;
+      },
+      selectionRender: defaultSelectionBuilder,
+    };
+  },
+
+  addStorage() {
+    return { users: [] as any[] };
+  },
+
+  onCreate() {
+    if (!this.options.provider) {
+      throw new Error('The "provider" option is required for CollaborationCursorV3');
+    }
+  },
+
+  addCommands() {
+    return {
+      updateUser:
+        (attributes: Record<string, any>) =>
+        () => {
+          this.options.user = attributes as any;
+          this.options.provider.awareness.setLocalStateField("user", this.options.user);
+          return true;
+        },
+    };
+  },
+
+  addProseMirrorPlugins() {
+    this.options.provider.awareness.setLocalStateField("user", this.options.user);
+    this.storage.users = awarenessStatesToArray(this.options.provider.awareness.states);
+    this.options.provider.awareness.on("update", () => {
+      this.storage.users = awarenessStatesToArray(this.options.provider.awareness.states);
+    });
+
+    return [
+      yCursorPlugin(
+        this.options.provider.awareness,
+        {
+          cursorBuilder: this.options.render ?? defaultCursorBuilder,
+          selectionBuilder: this.options.selectionRender ?? defaultSelectionBuilder,
+        },
+      ),
+    ];
+  },
+});

frontend/src/editor/extensions/collaboration-undo.ts

@@ -1,35 +1,22 @@
 import { Extension } from "@tiptap/core";
 import { UndoManager } from "yjs";
-import type { XmlFragment } from "yjs";
-
-declare module "@tiptap/core" {
-  interface Commands<ReturnType> {
-    collaborationUndo: {
-      undo: () => ReturnType;
-      redo: () => ReturnType;
-    };
-  }
-}
+import { yUndoPluginKey } from "@tiptap/y-tiptap";
 
 export interface CollaborationUndoOptions {
-  fragment: XmlFragment;
   onUndoManagerReady?: (manager: UndoManager) => void;
 }
 
 /**
- * Wraps Y.UndoManager as a TipTap extension, replacing the disabled
- * ProseMirror history with collaborative undo/redo.
- *
- * Agent edits can be grouped by calling undoManager.stopCapturing()
- * before and after a batch of changes - everything between two
- * stopCapturing() calls is merged into a single undo step.
+ * Thin extension that exposes the UndoManager created by @tiptap/extension-collaboration v3.
+ * The actual undo/redo commands and shortcuts are handled by the Collaboration extension itself.
+ * This extension only reads the UndoManager from the yUndoPlugin state and
+ * exposes it via onUndoManagerReady for external consumers (e.g. agent chat batching).
  */
 export const CollaborationUndo = Extension.create<CollaborationUndoOptions>({
-  name: "collaborationUndo",
+  name: "collaborationUndoBridge",
 
   addOptions() {
     return {
-      fragment: null as unknown as XmlFragment,
       onUndoManagerReady: undefined,
     };
   },
@@ -41,47 +28,11 @@ export const CollaborationUndo = Extension.create<CollaborationUndoOptions>({
   },
 
   onCreate() {
-    const um = new UndoManager(this.options.fragment, {
-      captureTimeout: 500,
-    });
-    this.storage.undoManager = um;
-    this.options.onUndoManagerReady?.(um);
-  },
-
-  onDestroy() {
-    this.storage.undoManager?.destroy();
-  },
-
-  addCommands() {
-    return {
-      undo:
-        () =>
-        () => {
-          const um = this.storage.undoManager;
-          if (um && um.undoStack.length > 0) {
-            um.undo();
-            return true;
-          }
-          return false;
-        },
-      redo:
-        () =>
-        () => {
-          const um = this.storage.undoManager;
-          if (um && um.redoStack.length > 0) {
-            um.redo();
-            return true;
-          }
-          return false;
-        },
-    };
-  },
-
-  addKeyboardShortcuts() {
-    return {
-      "Mod-z": () => this.editor.commands.undo(),
-      "Mod-Shift-z": () => this.editor.commands.redo(),
-      "Mod-y": () => this.editor.commands.redo(),
-    };
+    const state = this.editor.state;
+    const undoState = yUndoPluginKey.getState(state);
+    if (undoState?.undoManager) {
+      this.storage.undoManager = undoState.undoManager;
+      this.options.onUndoManagerReady?.(undoState.undoManager);
+    }
   },
 });