diff --git a/apps/cli/src/main.ts b/apps/cli/src/main.ts
index e41a723b89..71fd0bfaec 100644
--- a/apps/cli/src/main.ts
+++ b/apps/cli/src/main.ts
@@ -184,6 +184,7 @@ import {
   sanitizeCliOutputText,
   shellQuoteArg,
 } from "./tooling";
+import { generatePowerShellCompletions } from "./powershell-completions";
 
 // Embedded web UI — baked into compiled binaries via `with { type: "file" }`
 import embeddedWebUI from "./embedded-web-ui.gen";
@@ -3351,6 +3352,16 @@ const runCli = Command.run(root, {
   version: CLI_VERSION,
 });
 
+const isPowerShellCompletionRequest = (): boolean => {
+  const index = process.argv.indexOf("--completions");
+  return index >= 0 && process.argv[index + 1] === "pwsh";
+};
+
+if (isPowerShellCompletionRequest()) {
+  console.log(generatePowerShellCompletions());
+  process.exit(0);
+}
+
 if (process.argv.includes("-v")) {
   console.log(CLI_VERSION);
   process.exit(0);
diff --git a/apps/cli/src/powershell-completions.test.ts b/apps/cli/src/powershell-completions.test.ts
new file mode 100644
index 0000000000..99289d0248
--- /dev/null
+++ b/apps/cli/src/powershell-completions.test.ts
@@ -0,0 +1,18 @@
+import { describe, expect, it } from "@effect/vitest";
+
+import { generatePowerShellCompletions } from "./powershell-completions";
+
+describe("generatePowerShellCompletions", () => {
+  it("registers a native completer that discovers contextual help", () => {
+    const script = generatePowerShellCompletions();
+
+    expect(script).toContain("Register-ArgumentCompleter -Native -CommandName executor");
+    expect(script).toContain("& executor @arguments --help");
+    expect(script).toContain("GLOBAL FLAGS");
+    expect(script).toContain("SUBCOMMANDS");
+    expect(script).toContain("[regex]::Escape($previous)");
+    expect(script).toContain("$choices += 'pwsh'");
+    expect(script).toContain("^\\s+(--[a-z0-9-]+)");
+    expect(script).toContain("^\\s+([a-z][a-z0-9-]*)");
+  });
+});
diff --git a/apps/cli/src/powershell-completions.ts b/apps/cli/src/powershell-completions.ts
new file mode 100644
index 0000000000..4059c0d898
--- /dev/null
+++ b/apps/cli/src/powershell-completions.ts
@@ -0,0 +1,65 @@
+const completionScript = `# Register with: executor --completions pwsh | Invoke-Expression
+#
+# The completer reads Executor's contextual help at completion time. That keeps
+# commands and flags aligned with the installed CLI without a second command tree.
+Register-ArgumentCompleter -Native -CommandName executor -ScriptBlock {
+  param($wordToComplete, $commandAst, $cursorPosition)
+
+  $elements = @($commandAst.CommandElements | ForEach-Object { $_.Extent.Text })
+  $arguments = @($elements | Select-Object -Skip 1)
+  if ($arguments.Count -gt 0 -and $arguments[-1] -eq $wordToComplete) {
+    $arguments = @($arguments | Select-Object -SkipLast 1)
+  }
+
+  $help = & executor @arguments --help 2>$null
+  if ($LASTEXITCODE -ne 0) {
+    return
+  }
+
+  $previous = if ($arguments.Count -gt 0) { $arguments[-1] } else { "" }
+  if ($previous -like '--*') {
+    $escapedFlag = [regex]::Escape($previous)
+    $choiceLine = $help | Where-Object {
+      $_ -match "^\\s+$escapedFlag\\s+choice\\s+.*\\(choices:\\s+(.+)\\)$"
+    } | Select-Object -First 1
+    if ($choiceLine -match '\\(choices:\\s+(.+)\\)$') {
+      $choices = @($matches[1] -split ',\\s*')
+      if ($previous -eq '--completions') { $choices += 'pwsh' }
+      $choices |
+        Where-Object { $_ -like "$wordToComplete*" } |
+        Sort-Object -Unique |
+        ForEach-Object { [System.Management.Automation.CompletionResult]::new($_, $_, 'ParameterValue', $_) }
+      return
+    }
+  }
+
+  $section = ""
+  $candidates = foreach ($line in $help) {
+    if ($line -match '^[A-Z ]+$') {
+      $section = $line.Trim()
+      continue
+    }
+
+    if ($wordToComplete.StartsWith('-') -and ($section -eq 'GLOBAL FLAGS' -or $section -eq 'FLAGS')) {
+      if ($line -match '^\\s+(--[a-z0-9-]+)(?:,\\s+(-[a-z]))?\\s{2,}') {
+        $matches[1]
+        if ($matches[2]) { $matches[2] }
+      }
+      continue
+    }
+
+    if (-not $wordToComplete.StartsWith('-') -and $section -eq 'SUBCOMMANDS') {
+      if ($line -match '^\\s+([a-z][a-z0-9-]*)\\s{2,}') {
+        $matches[1]
+      }
+    }
+  }
+
+  $candidates |
+    Where-Object { $_ -like "$wordToComplete*" } |
+    Sort-Object -Unique |
+    ForEach-Object { [System.Management.Automation.CompletionResult]::new($_, $_, 'ParameterValue', $_) }
+}
+`;
+
+export const generatePowerShellCompletions = (): string => completionScript;