From eadc3eaf42b676962852f96643641c88648e4cbf Mon Sep 17 00:00:00 2001
From: Ubuntu <azureuser@opencode-vm.tail535b43.ts.net>
Date: Sun, 30 Aug 2026 13:48:58 +0000
Subject: [PATCH] fix: CLI commands web and serve don't show a useful message
 when port is used

---
 packages/opencode/src/cli/cmd/serve.ts | 10 +++++++---
 packages/opencode/src/cli/cmd/web.ts   | 10 +++++++---
 packages/opencode/src/cli/network.ts   |  5 +++++
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/packages/opencode/src/cli/cmd/serve.ts b/packages/opencode/src/cli/cmd/serve.ts
index c0f62b3ca071..2c8f8b083ff4 100644
--- a/packages/opencode/src/cli/cmd/serve.ts
+++ b/packages/opencode/src/cli/cmd/serve.ts
@@ -1,6 +1,6 @@
 import { Effect } from "effect"
-import { effectCmd } from "../effect-cmd"
-import { withNetworkOptions, resolveNetworkOptions } from "../network"
+import { effectCmd, fail } from "../effect-cmd"
+import { isPortInUseError, withNetworkOptions, resolveNetworkOptions } from "../network"
 import { Flag } from "@opencode-ai/core/flag/flag"
 
 export const ServeCommand = effectCmd({
@@ -16,7 +16,11 @@ export const ServeCommand = effectCmd({
       console.log("Warning: OPENCODE_SERVER_PASSWORD is not set; server is unsecured.")
     }
     const opts = yield* resolveNetworkOptions(args)
-    const server = yield* Effect.promise(() => Server.listen(opts))
+    const server = yield* Effect.promise(() => Server.listen(opts)).pipe(
+      Effect.catchDefect((error) =>
+        isPortInUseError(error) ? fail(`Port ${opts.port} is already in use`) : Effect.die(error),
+      ),
+    )
     console.log(`opencode server listening on http://${server.hostname}:${server.port}`)
 
     yield* Effect.never
diff --git a/packages/opencode/src/cli/cmd/web.ts b/packages/opencode/src/cli/cmd/web.ts
index 69a981aada49..4d213b74f576 100644
--- a/packages/opencode/src/cli/cmd/web.ts
+++ b/packages/opencode/src/cli/cmd/web.ts
@@ -1,7 +1,7 @@
 import { Effect } from "effect"
 import { UI } from "../ui"
-import { effectCmd } from "../effect-cmd"
-import { withNetworkOptions, resolveNetworkOptions } from "../network"
+import { effectCmd, fail } from "../effect-cmd"
+import { isPortInUseError, resolveNetworkOptions, withNetworkOptions } from "../network"
 import { Flag } from "@opencode-ai/core/flag/flag"
 import open from "open"
 import { networkInterfaces } from "os"
@@ -41,7 +41,11 @@ export const WebCommand = effectCmd({
       UI.println(UI.Style.TEXT_WARNING_BOLD + "!  OPENCODE_SERVER_PASSWORD is not set; server is unsecured.")
     }
     const opts = yield* resolveNetworkOptions(args)
-    const server = yield* Effect.promise(() => Server.listen(opts))
+    const server = yield* Effect.promise(() => Server.listen(opts)).pipe(
+      Effect.catchDefect((error) =>
+        isPortInUseError(error) ? fail(`Port ${opts.port} is already in use`) : Effect.die(error),
+      ),
+    )
     UI.empty()
     UI.println(UI.logo("  "))
     UI.empty()
diff --git a/packages/opencode/src/cli/network.ts b/packages/opencode/src/cli/network.ts
index 22040ed41015..71dcc3c10972 100644
--- a/packages/opencode/src/cli/network.ts
+++ b/packages/opencode/src/cli/network.ts
@@ -1,6 +1,7 @@
 import type { Argv, InferredOptionTypes } from "yargs"
 import { ConfigV1 } from "@opencode-ai/core/v1/config/config"
 import type { Config } from "@/config/config"
+import { isRecord } from "@/util/record"
 import { Effect } from "effect"
 
 const options = {
@@ -78,3 +79,7 @@ export function resolveNetworkOptionsNoConfig(args: NetworkOptions, config?: Con
 
   return { hostname, port, mdns, mdnsDomain, cors }
 }
+
+export function isPortInUseError(error: unknown) {
+  return isRecord(error) && isRecord(error.cause) && error.cause.code === "EADDRINUSE"
+}