fix: preserve quotes in slash command arguments

packages/opencode/src/session/prompt.ts

@@ -1899,8 +1899,7 @@ NOTE: At any point in time through this workflow you should feel free to ask the
       }
       const agentName = cmd.agent ?? input.agent
 
-      const raw = input.arguments.match(argsRegex) ?? []
-      const args = raw.map((arg) => arg.replace(quoteTrimRegex, ""))
+      const args = parseCommandArguments(input.arguments)
       const templateCommand = yield* Effect.promise(async () => cmd.template)
 
       const placeholders = templateCommand.match(placeholderRegex) ?? []
@@ -2151,7 +2150,11 @@ export function createStructuredOutputTool(input: {
 const bashRegex = /!`([^`]+)`/g
 // Match [Image N] as single token, quoted strings, or non-space sequences
 const argsRegex = /(?:\[Image\s+\d+\]|"[^"]*"|'[^']*'|[^\s"']+)/gi
-const placeholderRegex = /\$(\d+)/g
 const quoteTrimRegex = /^["']|["']$/g
+const placeholderRegex = /\$(\d+)/g
+
+export function parseCommandArguments(input: string) {
+  return (input.match(argsRegex) ?? []).map((arg) => arg.replace(quoteTrimRegex, ""))
+}
 
 export * as SessionPrompt from "./prompt"

packages/opencode/test/session/prompt-substitute.test.ts

@@ -0,0 +1,14 @@
+import { describe, expect, test } from "bun:test"
+import { SessionPrompt } from "../../src/session/prompt"
+
+describe("SessionPrompt.parseCommandArguments", () => {
+  test("preserves quoted multi-word arguments as a single argument", () => {
+    const result = SessionPrompt.parseCommandArguments('"sync|Syncing dev with upstream/dev"')
+    expect(result).toEqual(["sync|Syncing dev with upstream/dev"])
+  })
+
+  test("splits remaining unquoted arguments normally", () => {
+    const result = SessionPrompt.parseCommandArguments('"sync|Syncing dev with upstream/dev" tail one')
+    expect(result).toEqual(["sync|Syncing dev with upstream/dev", "tail", "one"])
+  })
+})