From 768a01326030cc6d2f7be835c539e17a93e862f8 Mon Sep 17 00:00:00 2001
From: Simon Gagnon <git@simoncrypta.dev>
Date: Tue, 31 Mar 2026 13:49:55 -0400
Subject: [PATCH] feat: add server_url_override config for tmux integration

Add server_url_override option to tmux configuration to allow users
to override the auto-detected server URL. This fixes issues where
opencode binds to VPN/Tailscale IPs with TLS certificate errors,
preventing the tmux health check from succeeding.

Changes:
- Add server_url_override field to TmuxConfigSchema
- Update TmuxSessionManager to use override URL when provided
- Pass server_url_override through plugin config initialization

Users can now set tmux.server_url_override to "http://localhost:4096"
to force localhost instead of using auto-detected IPs.
---
 src/config/schema/tmux.ts             | 11 +++++++++++
 src/features/tmux-subagent/manager.ts | 26 ++++++++++++++++++--------
 src/index.ts                          |  1 +
 src/plugin/types.ts                   |  1 +
 4 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/src/config/schema/tmux.ts b/src/config/schema/tmux.ts
index 77582cf408..09c97d6869 100644
--- a/src/config/schema/tmux.ts
+++ b/src/config/schema/tmux.ts
@@ -21,6 +21,17 @@ export const TmuxConfigSchema = z.object({
   main_pane_min_width: z.number().min(40).default(120),
   agent_pane_min_width: z.number().min(20).default(40),
   isolation: TmuxIsolationSchema.default("session"),
+  /**
+   * Override the server URL used for health checks and pane spawning.
+   * Use this when opencode auto-detects the wrong IP (e.g., Tailscale).
+   * Example: "http://localhost:4096"
+   */
+  server_url_override: z
+    .preprocess(
+      (val) => (val === "" || val === null ? undefined : val),
+      z.string().url().optional()
+    )
+    .optional(),
 })
 
 export type TmuxConfig = z.infer<typeof TmuxConfigSchema>
diff --git a/src/features/tmux-subagent/manager.ts b/src/features/tmux-subagent/manager.ts
index 0777417673..c75826b89c 100644
--- a/src/features/tmux-subagent/manager.ts
+++ b/src/features/tmux-subagent/manager.ts
@@ -77,17 +77,27 @@ export class TmuxSessionManager {
     this.deps = deps
     const defaultPort = process.env.OPENCODE_PORT ?? "4096"
     const fallbackUrl = `http://localhost:${defaultPort}`
-    try {
-      const raw = ctx.serverUrl?.toString()
-      if (raw) {
-        const parsed = new URL(raw)
+    if (tmuxConfig.server_url_override) {
+      try {
+        const parsed = new URL(tmuxConfig.server_url_override)
         const port = parsed.port || (parsed.protocol === 'https:' ? '443' : '80')
-        this.serverUrl = port === '0' ? fallbackUrl : raw
-      } else {
+        this.serverUrl = port === '0' ? fallbackUrl : tmuxConfig.server_url_override
+      } catch {
+        this.serverUrl = fallbackUrl
+      }
+    } else {
+      try {
+        const raw = ctx.serverUrl?.toString()
+        if (raw) {
+          const parsed = new URL(raw)
+          const port = parsed.port || (parsed.protocol === 'https:' ? '443' : '80')
+          this.serverUrl = port === '0' ? fallbackUrl : raw
+        } else {
+          this.serverUrl = fallbackUrl
+        }
+      } catch {
         this.serverUrl = fallbackUrl
       }
-    } catch {
-      this.serverUrl = fallbackUrl
     }
     this.sourcePaneId = deps.getCurrentPaneId()
     this.pollingManager = new TmuxPollingManager(
diff --git a/src/index.ts b/src/index.ts
index 1a080167a1..e5e60b1a57 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -51,6 +51,7 @@ const OhMyOpenCodePlugin: Plugin = async (ctx) => {
     main_pane_min_width: pluginConfig.tmux?.main_pane_min_width ?? 120,
     agent_pane_min_width: pluginConfig.tmux?.agent_pane_min_width ?? 40,
     isolation: pluginConfig.tmux?.isolation ?? "session",
+    server_url_override: pluginConfig.tmux?.server_url_override,
   }
 
   const modelCacheState = createModelCacheState()
diff --git a/src/plugin/types.ts b/src/plugin/types.ts
index b713781bd3..30359cbe5e 100644
--- a/src/plugin/types.ts
+++ b/src/plugin/types.ts
@@ -23,4 +23,5 @@ export type TmuxConfig = {
   main_pane_min_width: number
   agent_pane_min_width: number
   isolation: "inline" | "window" | "session"
+  server_url_override?: string
 }