From effb48ea91c21301724e321f487de23f46b78c78 Mon Sep 17 00:00:00 2001
From: Kit Langton <kit.langton@gmail.com>
Date: Wed, 12 Aug 2026 22:47:37 -0400
Subject: [PATCH] feat(tui): highlight Bash commands

---
 packages/tui/src/component/prompt/index.tsx | 43 +++++++++++++++++++++
 packages/tui/src/routes/session/index.tsx   | 26 +++++++++++--
 2 files changed, 66 insertions(+), 3 deletions(-)

diff --git a/packages/tui/src/component/prompt/index.tsx b/packages/tui/src/component/prompt/index.tsx
index af2f40bf793..d524a8bc739 100644
--- a/packages/tui/src/component/prompt/index.tsx
+++ b/packages/tui/src/component/prompt/index.tsx
@@ -5,6 +5,7 @@ import {
   MouseEvent,
   PasteEvent,
   decodePasteBytes,
+  getTreeSitterClient,
   type ColorInput,
   type KeyEvent,
 } from "@opentui/core"
@@ -98,6 +99,7 @@ export type PromptRef = {
 }
 
 const DRAFT_RETENTION_MIN_CHARS = 20
+const SHELL_SYNTAX_HIGHLIGHT_REF = 65_535
 
 function randomIndex(count: number) {
   if (count <= 0) return 0
@@ -340,6 +342,47 @@ export function Prompt(props: PromptProps) {
   })
   let disposed = false
   let pasteQueue = Promise.resolve()
+  let syntaxHighlightVersion = 0
+
+  createEffect(() => {
+    const mode = store.mode
+    const content = store.prompt.text
+    const style = syntax()
+    const version = ++syntaxHighlightVersion
+
+    if (input && !input.isDestroyed) input.editBuffer.removeHighlightsByRef(SHELL_SYNTAX_HIGHLIGHT_REF)
+    if (mode !== "shell" || !content || !input || input.isDestroyed) return
+
+    const timeout = setTimeout(() => {
+      getTreeSitterClient()
+        .highlightOnce(content, "bash")
+        .then((result) => {
+          if (version !== syntaxHighlightVersion || !result.highlights || !input || input.isDestroyed) return
+
+          const bytes = new TextEncoder().encode(content)
+          const decoder = new TextDecoder()
+          result.highlights.forEach(([start, end, group]) => {
+            const styleId = style.getStyleId(group)
+            if (styleId === null) return
+            const before = decoder.decode(bytes.subarray(0, start))
+            const highlighted = decoder.decode(bytes.subarray(start, end))
+            input.editBuffer.addHighlightByCharRange({
+              start: promptOffsetWidth(before) - (before.match(/\n/g)?.length ?? 0),
+              end:
+                promptOffsetWidth(before) +
+                promptOffsetWidth(highlighted) -
+                ((before + highlighted).match(/\n/g)?.length ?? 0),
+              styleId,
+              priority: 0,
+              hlRef: SHELL_SYNTAX_HIGHLIGHT_REF,
+            })
+          })
+          renderer.requestRender()
+        })
+        .catch(() => {})
+    }, 50)
+    onCleanup(() => clearTimeout(timeout))
+  })
 
   function enqueuePaste(run: (changed: () => boolean) => Promise<void>) {
     pasteQueue = pasteQueue
diff --git a/packages/tui/src/routes/session/index.tsx b/packages/tui/src/routes/session/index.tsx
index f9c1eeb1808..44c4f719d4c 100644
--- a/packages/tui/src/routes/session/index.tsx
+++ b/packages/tui/src/routes/session/index.tsx
@@ -1938,6 +1938,7 @@ function RevertMessage(props: {
 
 function ShellMessage(props: { message: Extract<SessionMessageInfo, { type: "shell" }> }) {
   const theme = useTheme("elevated")
+  const { currentSyntax: syntax } = useThemes()
   const output = createMemo(() => stripAnsi(props.message.output?.output.trim() ?? ""))
 
   return (
@@ -1952,7 +1953,16 @@ function ShellMessage(props: { message: Extract<SessionMessageInfo, { type: "she
       customBorderChars={SplitBorder.customBorderChars}
       borderColor={theme.background.default}
     >
-      <text fg={theme.text.default}>$ {props.message.command}</text>
+      <box flexDirection="row" gap={1}>
+        <text fg={theme.text.default}>$</text>
+        <code
+          conceal={false}
+          fg={theme.text.default}
+          filetype="bash"
+          syntaxStyle={syntax()}
+          content={props.message.command}
+        />
+      </box>
       <Show when={output()}>
         <text fg={theme.text.subdued}>{output()}</text>
       </Show>
@@ -2784,6 +2794,7 @@ const SHELL_DISPLAY_LIMIT = 1024 * 1024
 
 function Shell(props: ToolProps) {
   const theme = useTheme()
+  const { currentSyntax: syntax } = useThemes()
   const ctx = use()
   const client = useClient()
   const data = useData()
@@ -2915,11 +2926,20 @@ function Shell(props: ToolProps) {
             fallback={
               <box flexDirection="row" gap={1}>
                 <text fg={theme.text.default}>{prompt()}</text>
-                <text fg={theme.text.default}>{limitedInput()}</text>
+                <code
+                  conceal={false}
+                  fg={theme.text.default}
+                  filetype="bash"
+                  syntaxStyle={syntax()}
+                  content={limitedInput()}
+                />
               </box>
             }
           >
-            <Spinner color={color()}>{limitedInput()}</Spinner>
+            <box flexDirection="row" gap={1}>
+              <Spinner color={color()} />
+              <code conceal={false} fg={color()} filetype="bash" syntaxStyle={syntax()} content={limitedInput()} />
+            </box>
           </Show>
           <Show when={limitedOutput()}>
             <text fg={theme.text.subdued}>{limitedOutput()}</text>