diff --git a/extensions/CustomSuggestion/findSuggestionMatch.tsx b/extensions/CustomSuggestion/findSuggestionMatch.tsx
new file mode 100644
index 00000000..85bdcb80
--- /dev/null
+++ b/extensions/CustomSuggestion/findSuggestionMatch.tsx
@@ -0,0 +1,80 @@
+import { escapeForRegEx, Range } from '@tiptap/core'
+import { ResolvedPos } from '@tiptap/pm/model'
+
+export interface Trigger {
+  char: string
+  allowSpaces: boolean
+  allowedPrefixes: string[] | null
+  startOfLine: boolean
+  $position: ResolvedPos
+}
+
+export type SuggestionMatch = {
+  range: Range
+  query: string
+  text: string
+} | null
+
+export function findSuggestionMatch(config: Trigger): SuggestionMatch {
+  const { char, allowSpaces, allowedPrefixes, startOfLine, $position } = config
+
+  const escapedChar = escapeForRegEx(char)
+  const suffix = new RegExp(`\\s${escapedChar}$`)
+  const prefix = startOfLine ? '^' : ''
+  // const regexp = allowSpaces
+  //   ? new RegExp(`${prefix}${escapedChar}.*?(?=\\s${escapedChar}|$)`, 'gm')
+  //   : new RegExp(`${prefix}(?:^)?${escapedChar}[^\\s${escapedChar}]*`, 'gm')
+  const regexp = new RegExp(`^(.*)$`, 'gm')
+
+  const text = $position.nodeBefore?.isText && $position.nodeBefore.text
+
+  if (!text) {
+    return null
+  }
+
+  const textFrom = $position.pos - text.length
+  const match = Array.from(text.matchAll(regexp)).pop()
+
+  if (!match || match.input === undefined || match.index === undefined) {
+    return null
+  }
+
+  // JavaScript doesn't have lookbehinds. This hacks a check that first character
+  // is a space or the start of the line
+  const matchPrefix = match.input.slice(
+    Math.max(0, match.index - 1),
+    match.index
+  )
+  const matchPrefixIsAllowed = new RegExp(
+    `^[${allowedPrefixes?.join('')}\0]?$`
+  ).test(matchPrefix)
+
+  if (allowedPrefixes !== null && !matchPrefixIsAllowed) {
+    return null
+  }
+
+  // The absolute position of the match in the document
+  const from = textFrom + match.index
+  let to = from + match[0].length
+
+  // Edge case handling; if spaces are allowed and we're directly in between
+  // two triggers
+  if (allowSpaces && suffix.test(text.slice(to - 1, to + 1))) {
+    match[0] += ' '
+    to += 1
+  }
+
+  // If the $position is located within the matched substring, return that range
+  if (from < $position.pos && to >= $position.pos) {
+    return {
+      range: {
+        from,
+        to,
+      },
+      query: match[0],
+      text: match[0],
+    }
+  }
+
+  return null
+}
diff --git a/extensions/CustomSuggestion/index.tsx b/extensions/CustomSuggestion/index.tsx
new file mode 100644
index 00000000..914c2bb1
--- /dev/null
+++ b/extensions/CustomSuggestion/index.tsx
@@ -0,0 +1,291 @@
+import { Editor, Range } from '@tiptap/core'
+import { EditorState, Plugin, PluginKey } from '@tiptap/pm/state'
+import { Decoration, DecorationSet, EditorView } from '@tiptap/pm/view'
+
+import { findSuggestionMatch } from './findSuggestionMatch'
+
+export interface SuggestionOptions<I = any> {
+  pluginKey?: PluginKey
+  editor: Editor
+  char?: string
+  allowSpaces?: boolean
+  allowedPrefixes?: string[] | null
+  startOfLine?: boolean
+  decorationTag?: string
+  decorationClass?: string
+  command?: (props: { editor: Editor; range: Range; props: I }) => void
+  items?: (props: { query: string; editor: Editor }) => I[] | Promise<I[]>
+  render?: () => {
+    onBeforeStart?: (props: SuggestionProps<I>) => void
+    onStart?: (props: SuggestionProps<I>) => void
+    onBeforeUpdate?: (props: SuggestionProps<I>) => void
+    onUpdate?: (props: SuggestionProps<I>) => void
+    onExit?: (props: SuggestionProps<I>) => void
+    onFocus?: (props: SuggestionProps<I>) => void
+    onKeyDown?: (props: SuggestionKeyDownProps) => boolean
+  }
+  allow?: (props: {
+    editor: Editor
+    state: EditorState
+    range: Range
+  }) => boolean
+}
+
+export interface SuggestionProps<I = any> {
+  editor: Editor
+  range: Range
+  query: string
+  text: string
+  items: I[]
+  command: (props: I) => void
+  decorationNode: Element | null
+  clientRect?: (() => DOMRect) | null
+}
+
+export interface SuggestionKeyDownProps {
+  view: EditorView
+  event: KeyboardEvent
+  range: Range
+}
+
+export const SuggestionPluginKey = new PluginKey('suggestion')
+
+export function CustomSuggestion<I = any>({
+  pluginKey = SuggestionPluginKey,
+  editor,
+  char = '@',
+  allowSpaces = true,
+  allowedPrefixes = [' '],
+  startOfLine = false,
+  decorationTag = 'span',
+  decorationClass = 'suggestion',
+  command = () => null,
+  items = () => [],
+  render = () => ({}),
+  allow = () => true,
+}: SuggestionOptions<I>) {
+  let props: SuggestionProps<I> | undefined
+  const renderer = render?.()
+
+  const plugin: Plugin<any> = new Plugin({
+    key: pluginKey,
+
+    view() {
+      return {
+        update: async (view, prevState) => {
+          // This should be this.key?
+          const prev = pluginKey.getState(prevState)
+          const next = pluginKey.getState(view.state)
+
+          // See how the state changed
+          const moved =
+            prev.active && next.active && prev.range.from !== next.range.from
+          const started = !prev.active && next.active
+          const stopped = prev.active && !next.active
+          const changed = !started && !stopped && prev.query !== next.query
+          const handleStart = started || moved
+          const handleChange = changed && !moved
+          const handleExit = stopped || moved
+          const handleFocused = view.hasFocus()
+          console.log(handleFocused)
+
+          // Cancel when suggestion isn't active
+          if (!handleStart && !handleChange && !handleExit && !handleFocused) {
+            return
+          }
+
+          const state = handleExit && !handleStart ? prev : next
+          const decorationNode = view.dom.querySelector(
+            `[data-decoration-id="${state.decorationId}"]`
+          )
+
+          props = {
+            editor,
+            range: state.range,
+            query: state.query,
+            text: state.text,
+            items: [],
+            command: (commandProps) => {
+              command({
+                editor,
+                range: state.range,
+                props: commandProps,
+              })
+            },
+            decorationNode,
+            // virtual node for popper.js or tippy.js
+            // this can be used for building popups without a DOM node
+            clientRect: decorationNode
+              ? () => {
+                  // because of `items` can be asynchrounous we’ll search for the current decoration node
+                  const { decorationId } = pluginKey.getState(editor.state) // eslint-disable-line
+                  const currentDecorationNode = view.dom.querySelector(
+                    `[data-decoration-id="${decorationId}"]`
+                  )
+
+                  // @ts-ignore-error
+                  return currentDecorationNode.getBoundingClientRect()
+                }
+              : null,
+          }
+
+          if (handleFocused) {
+            console.log('Handling focus')
+          }
+
+          if (handleStart) {
+            renderer?.onBeforeStart?.(props)
+          }
+
+          if (handleChange) {
+            renderer?.onBeforeUpdate?.(props)
+          }
+
+          if (handleChange || handleStart) {
+            props.items = await items({
+              editor,
+              query: state.query,
+            })
+          }
+
+          if (handleExit) {
+            renderer?.onExit?.(props)
+          }
+
+          if (handleChange) {
+            renderer?.onUpdate?.(props)
+          }
+
+          if (handleStart) {
+            renderer?.onStart?.(props)
+          }
+        },
+
+        destroy: () => {
+          if (!props) {
+            return
+          }
+
+          renderer?.onExit?.(props)
+        },
+      }
+    },
+
+    state: {
+      // Initialize the plugin's internal state.
+      init() {
+        const state: {
+          active: boolean
+          range: Range
+          query: null | string
+          text: null | string
+          composing: boolean
+          decorationId?: string | null
+        } = {
+          active: false,
+          range: {
+            from: 0,
+            to: 0,
+          },
+          query: null,
+          text: null,
+          composing: false,
+        }
+
+        return state
+      },
+
+      // Apply changes to the plugin state from a view transaction.
+      apply(transaction, prev, oldState, state) {
+        const { isEditable } = editor
+        const { composing } = editor.view
+        const { selection } = transaction
+        const { empty, from } = selection
+        const next = { ...prev }
+
+        next.composing = composing
+
+        // We can only be suggesting if the view is editable, and:
+        //   * there is no selection, or
+        //   * a composition is active (see: https://github.com/ueberdosis/tiptap/issues/1449)
+        if (isEditable && (empty || editor.view.composing)) {
+          // Reset active state if we just left the previous suggestion range
+          if (
+            (from < prev.range.from || from > prev.range.to) &&
+            !composing &&
+            !prev.composing
+          ) {
+            next.active = false
+          }
+
+          // Try to match against where our cursor currently is
+          const match = findSuggestionMatch({
+            char,
+            allowSpaces,
+            allowedPrefixes,
+            startOfLine,
+            $position: selection.$from,
+          })
+          const decorationId = `id_${Math.floor(Math.random() * 0xffffffff)}`
+
+          // If we found a match, update the current state to show it
+          if (match && allow({ editor, state, range: match.range })) {
+            next.active = true
+            next.decorationId = prev.decorationId
+              ? prev.decorationId
+              : decorationId
+            next.range = match.range
+            next.query = match.query
+            next.text = match.text
+          } else {
+            next.active = false
+          }
+        } else {
+          next.active = false
+        }
+
+        // Make sure to empty the range if suggestion is inactive
+        if (!next.active) {
+          next.decorationId = null
+          next.range = { from: 0, to: 0 }
+          next.query = null
+          next.text = null
+        }
+
+        return next
+      },
+    },
+
+    props: {
+      // Call the keydown hook if suggestion is active.
+      handleKeyDown(view, event) {
+        const { active, range } = plugin.getState(view.state)
+
+        if (!active) {
+          return false
+        }
+
+        return renderer?.onKeyDown?.({ view, event, range }) || false
+      },
+
+      // Setup decorator on the currently active suggestion.
+      decorations(state) {
+        const { active, range, decorationId } = plugin.getState(state)
+
+        if (!active) {
+          return null
+        }
+
+        return DecorationSet.create(state.doc, [
+          Decoration.inline(range.from, range.to, {
+            nodeName: decorationTag,
+            class: decorationClass,
+            'data-decoration-id': decorationId,
+          }),
+        ])
+      },
+    },
+  })
+
+  return plugin
+}