feat(tui): paste primary selection on middle click

packages/tui/src/app.tsx

@@ -1091,6 +1091,12 @@ function App(props: { onSnapshot?: () => Promise<string[]>; pluginHost: TuiPlugi
       flexDirection="column"
       backgroundColor={theme.background}
       onMouseDown={(evt) => {
+        if (evt.button === MouseButton.MIDDLE && process.platform === "linux") {
+          evt.preventDefault()
+          evt.stopPropagation()
+          keymap.dispatchCommand("prompt.paste.primary")
+          return
+        }
         if (!Flag.OPENCODE_EXPERIMENTAL_DISABLE_COPY_ON_SELECT) return
         if (evt.button !== MouseButton.RIGHT) return
 
@@ -1100,7 +1106,10 @@ function App(props: { onSnapshot?: () => Promise<string[]>; pluginHost: TuiPlugi
       }}
       onMouseUp={
         !Flag.OPENCODE_EXPERIMENTAL_DISABLE_COPY_ON_SELECT
-          ? () => Selection.copy(renderer, toast, clipboard)
+          ? (evt) => {
+              if (evt.button === MouseButton.MIDDLE) return
+              Selection.copy(renderer, toast, clipboard)
+            }
           : undefined
       }
     >

packages/tui/src/clipboard.ts

@@ -94,6 +94,38 @@ export function copyCommand(
   }
 }
 
+export function readPrimaryCommand(
+  os: NodeJS.Platform,
+  wayland: boolean,
+  has: (name: string) => boolean,
+): string[] | undefined {
+  if (os !== "linux") return
+  if (wayland && has("wl-paste")) return ["wl-paste", "--primary", "--no-newline"]
+  if (has("xclip")) return ["xclip", "-selection", "primary", "-o"]
+  if (has("xsel")) return ["xsel", "--primary", "--output"]
+}
+
+let readPrimaryMethod: Promise<(() => Promise<string | undefined>) | undefined> | undefined
+
+function getReadPrimaryMethod() {
+  return (readPrimaryMethod ??= (async () => {
+    const { which } = await import("@opencode-ai/core/util/which")
+    const native = readPrimaryCommand(platform(), Boolean(process.env.WAYLAND_DISPLAY), (name) => Boolean(which(name)))
+    if (!native) return
+    return async () => {
+      const output = await command(native[0], native.slice(1)).catch(() => Buffer.alloc(0))
+      if (!output.length) return
+      return output.toString("utf8")
+    }
+  })())
+}
+
+// X11/Wayland primary selection: the buffer that middle click traditionally pastes.
+export async function readPrimary() {
+  const method = await getReadPrimaryMethod()
+  return method?.()
+}
+
 let copyMethod: Promise<(text: string) => Promise<void>> | undefined
 
 function getCopyMethod() {

packages/tui/src/component/prompt/index.tsx

@@ -389,6 +389,18 @@ export function Prompt(props: PromptProps) {
           }
         },
       },
+      {
+        title: "Paste primary selection",
+        name: "prompt.paste.primary",
+        category: "Prompt",
+        hidden: true,
+        enabled: process.platform === "linux",
+        run: async () => {
+          const text = await clipboard.readPrimary?.()
+          if (!text) return
+          await pasteInputText(text)
+        },
+      },
       {
         title: "Interrupt session",
         name: "session.interrupt",

packages/tui/src/context/clipboard.tsx

@@ -1,12 +1,13 @@
 import { createContext, type JSX, useContext } from "solid-js"
-import { read, write } from "../clipboard"
+import { read, readPrimary, write } from "../clipboard"
 
 export type ClipboardContent = Readonly<{ data: string; mime: string }>
 export type ClipboardService = Readonly<{
   read?(): Promise<ClipboardContent | undefined>
   write?(text: string): Promise<void>
+  readPrimary?(): Promise<string | undefined>
 }>
-const clipboard = { read, write }
+const clipboard = { read, write, readPrimary }
 const ClipboardContext = createContext<ClipboardService>(clipboard)
 
 export function ClipboardProvider(props: { value?: ClipboardService; children: JSX.Element }) {

packages/tui/test/clipboard.test.ts

@@ -1,5 +1,5 @@
 import { expect, test } from "bun:test"
-import { copyCommand } from "../src/clipboard"
+import { copyCommand, readPrimaryCommand } from "../src/clipboard"
 
 test("prefers Wayland clipboard when available", () => {
   expect(copyCommand("linux", true, (name) => name === "wl-copy")).toEqual(["wl-copy"])
@@ -17,3 +17,17 @@ test("falls back through X11 clipboard commands", () => {
 test("returns undefined when native clipboard is unavailable", () => {
   expect(copyCommand("linux", false, () => false)).toBeUndefined()
 })
+
+test("reads primary selection with Wayland tooling when available", () => {
+  expect(readPrimaryCommand("linux", true, (name) => name === "wl-paste")).toEqual(["wl-paste", "--primary", "--no-newline"])
+})
+
+test("falls back through X11 primary selection commands", () => {
+  expect(readPrimaryCommand("linux", false, (name) => name === "xclip")).toEqual(["xclip", "-selection", "primary", "-o"])
+  expect(readPrimaryCommand("linux", false, (name) => name === "xsel")).toEqual(["xsel", "--primary", "--output"])
+})
+
+test("returns undefined for primary selection on non-Linux platforms", () => {
+  expect(readPrimaryCommand("darwin", true, () => true)).toBeUndefined()
+  expect(readPrimaryCommand("win32", true, () => true)).toBeUndefined()
+})