fix(ui): avoid stripping non-path @mentions

packages/ui/src/components/prompt-input/usePromptPicker.ts

@@ -1,7 +1,7 @@
 import { createSignal, type Accessor, type Setter } from "solid-js"
 import type { Command as SDKCommand } from "@opencode-ai/sdk/v2"
 import type { Agent } from "../../types/session"
-import { createAgentAttachment, createFileAttachment, createTextAttachment } from "../../types/attachment"
+import { createAgentAttachment, createFileAttachment } from "../../types/attachment"
 import { addAttachment, getAttachments, removeAttachment } from "../../stores/attachments"
 import type { PickerMode } from "./types"
 import type { PickerSelectAction } from "../unified-picker"
@@ -213,18 +213,6 @@ export function usePromptPicker(options: PromptPickerOptions): PromptPickerContr
         return trimmed.length > 0 ? trimmed : "."
       })()
 
-      const addPathOnlyAttachment = (value: string) => {
-        const display = `path: ${value}`
-        const filename = value
-        const existing = getAttachments(options.instanceId(), options.sessionId())
-        const alreadyAttached = existing.some(
-          (att) => att.source.type === "text" && att.source.value === value && att.display === display,
-        )
-        if (!alreadyAttached) {
-          addAttachment(options.instanceId(), options.sessionId(), createTextAttachment(value, display, filename))
-        }
-      }
-
       if (isFolder) {
         if (action === "tab") {
           // TAB on directory: autocomplete directory name and show its contents.

packages/ui/src/lib/prompt-placeholders.ts

@@ -5,21 +5,87 @@ export function resolvePastedPlaceholders(prompt: string, attachments: Attachmen
     return prompt
   }
 
-  // First, strip @ from file/directory paths that don't have file attachments
-  // This handles SHIFT+ENTER case where @path should become path
-  const fileAttachments = new Set(
+  // First, strip `@` from path-like mentions that do NOT have a backing file attachment.
+  // This is intended for SHIFT+ENTER selection where we keep `@path` in the textarea for
+  // easy deletion, but send `path` to the API.
+  //
+  // IMPORTANT: avoid rewriting plain `@mentions` or email addresses.
+  const fileAttachmentPaths = new Set(
     attachments
-      .filter((a) => a.source.type === "file" && "path" in a.source)
-      .map((a) => (a.source as { path: string }).path),
+      .filter((a) => a.source.type === "file")
+      .map((a) => a.source.path),
   )
 
-  let result = prompt.replace(/@([^\s@]+)/g, (match, path) => {
-    // If this path has a file attachment, keep the @ (attachment is sent separately)
-    if (fileAttachments.has(path) || fileAttachments.has(path.replace(/\/$/, ""))) {
-      return match
+  const isPathLike = (value: string) => {
+    if (!value) return false
+    if (value.includes("/") || value.includes("\\")) return true
+    if (value.startsWith("./") || value.startsWith("../")) return true
+    if (value.startsWith("~")) return true
+    if (value.endsWith("/")) return true
+
+    // Root-level files (no `/`) still commonly have an extension.
+    const ext = value.split(".").pop()?.toLowerCase()
+    if (!ext || ext === value.toLowerCase()) return false
+
+    // Keep this list intentionally small and code-focused to avoid matching domains like `example.com`.
+    const allowedExts = new Set([
+      "ts",
+      "tsx",
+      "js",
+      "jsx",
+      "mjs",
+      "cjs",
+      "json",
+      "md",
+      "txt",
+      "yml",
+      "yaml",
+      "toml",
+      "css",
+      "html",
+      "htm",
+      "svg",
+      "png",
+      "jpg",
+      "jpeg",
+      "gif",
+      "pdf",
+      "rs",
+      "go",
+      "py",
+      "java",
+      "kt",
+      "swift",
+      "sh",
+      "bash",
+      "zsh",
+      "sql",
+      "lock",
+    ])
+    return allowedExts.has(ext)
+  }
+
+  const stripTrailingPunctuation = (value: string) => {
+    const match = value.match(/^(.*?)([)\]}.,!?:;]+)?$/)
+    if (!match) return { core: value, trailing: "" }
+    return { core: match[1] ?? value, trailing: match[2] ?? "" }
+  }
+
+  let result = prompt.replace(/(^|[\s([{"'`])@([^\s@]+)/g, (full, prefix, rawToken) => {
+    const { core, trailing } = stripTrailingPunctuation(String(rawToken))
+    if (!core) return full
+
+    // If this path has a file attachment, keep the `@` (attachment is sent separately).
+    if (fileAttachmentPaths.has(core) || fileAttachmentPaths.has(core.replace(/\/$/, ""))) {
+      return `${prefix}@${core}${trailing}`
     }
-    // Otherwise (SHIFT+ENTER case), strip the @
-    return path
+
+    // Only strip for path-like tokens; leave plain `@mentions` intact.
+    if (!isPathLike(core)) {
+      return `${prefix}@${core}${trailing}`
+    }
+
+    return `${prefix}${core}${trailing}`
   })
 
   // Then, resolve [pasted #N] placeholders