From 76cfd33b527599efb2e7c24929789ed318e0a764 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rolf=20Sch=C3=A4uble?= <rolf@rschaeuble.de>
Date: Fri, 20 Feb 2026 23:59:12 +0100
Subject: [PATCH] fix: avoid default web port conflict in acp

---
 packages/opencode/src/cli/cmd/acp.ts   |  2 +-
 packages/opencode/src/server/server.ts | 20 ++++++++++++--------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/packages/opencode/src/cli/cmd/acp.ts b/packages/opencode/src/cli/cmd/acp.ts
index 99a9a81ab9cd..2f41f6749feb 100644
--- a/packages/opencode/src/cli/cmd/acp.ts
+++ b/packages/opencode/src/cli/cmd/acp.ts
@@ -23,7 +23,7 @@ export const AcpCommand = cmd({
     process.env.OPENCODE_CLIENT = "acp"
     await bootstrap(process.cwd(), async () => {
       const opts = await resolveNetworkOptions(args)
-      const server = Server.listen(opts)
+      const server = Server.listen(opts, false)
 
       const sdk = createOpencodeClient({
         baseUrl: `http://${server.hostname}:${server.port}`,
diff --git a/packages/opencode/src/server/server.ts b/packages/opencode/src/server/server.ts
index 9fba9c1fe1a0..83b3c8b0b93f 100644
--- a/packages/opencode/src/server/server.ts
+++ b/packages/opencode/src/server/server.ts
@@ -573,13 +573,16 @@ export namespace Server {
     return result
   }
 
-  export function listen(opts: {
-    port: number
-    hostname: string
-    mdns?: boolean
-    mdnsDomain?: string
-    cors?: string[]
-  }) {
+  export function listen(
+    opts: {
+      port: number
+      hostname: string
+      mdns?: boolean
+      mdnsDomain?: string
+      cors?: string[]
+    },
+    prefer_default_port = true,
+  ) {
     _corsWhitelist = opts.cors ?? []
 
     const args = {
@@ -595,7 +598,8 @@ export namespace Server {
         return undefined
       }
     }
-    const server = opts.port === 0 ? (tryServe(4096) ?? tryServe(0)) : tryServe(opts.port)
+    const preferred = opts.port !== 0 ? opts.port : prefer_default_port ? 4096 : 0
+    const server = tryServe(preferred) ?? (preferred === 0 ? undefined : tryServe(0))
     if (!server) throw new Error(`Failed to start server on port ${opts.port}`)
 
     _url = server.url