diff --git a/packages/opencode/src/cli/cmd/serve.ts b/packages/opencode/src/cli/cmd/serve.ts
index bee2c8f711f..148c335ed33 100644
--- a/packages/opencode/src/cli/cmd/serve.ts
+++ b/packages/opencode/src/cli/cmd/serve.ts
@@ -8,6 +8,10 @@ export const ServeCommand = cmd({
   builder: (yargs) => withNetworkOptions(yargs),
   describe: "starts a headless opencode server",
   handler: async (args) => {
+    // Exit on terminal closure or termination
+    process.on("SIGHUP", () => process.exit(0))
+    process.on("SIGTERM", () => process.exit(0))
+
     if (!Flag.OPENCODE_SERVER_PASSWORD) {
       console.log("Warning: OPENCODE_SERVER_PASSWORD is not set; server is unsecured.")
     }
diff --git a/packages/opencode/src/cli/cmd/tui/attach.ts b/packages/opencode/src/cli/cmd/tui/attach.ts
index e852cb73d4c..ff20e1c577e 100644
--- a/packages/opencode/src/cli/cmd/tui/attach.ts
+++ b/packages/opencode/src/cli/cmd/tui/attach.ts
@@ -26,6 +26,10 @@ export const AttachCommand = cmd({
         describe: "basic auth password (defaults to OPENCODE_SERVER_PASSWORD)",
       }),
   handler: async (args) => {
+    // Exit on terminal closure or termination
+    process.on("SIGHUP", () => process.exit(0))
+    process.on("SIGTERM", () => process.exit(0))
+
     const directory = (() => {
       if (!args.dir) return undefined
       try {
diff --git a/packages/opencode/src/cli/cmd/tui/thread.ts b/packages/opencode/src/cli/cmd/tui/thread.ts
index 2ea49ff6b2b..6da7e826013 100644
--- a/packages/opencode/src/cli/cmd/tui/thread.ts
+++ b/packages/opencode/src/cli/cmd/tui/thread.ts
@@ -118,6 +118,14 @@ export const TuiThreadCommand = cmd({
       await client.call("reload", undefined)
     })
 
+    // Graceful shutdown on terminal closure or termination
+    const shutdown = async () => {
+      await client.call("shutdown", undefined).catch(() => {})
+      process.exit(0)
+    }
+    process.on("SIGHUP", shutdown)
+    process.on("SIGTERM", shutdown)
+
     const prompt = await iife(async () => {
       const piped = !process.stdin.isTTY ? await Bun.stdin.text() : undefined
       if (!args.prompt) return piped
diff --git a/packages/opencode/src/cli/cmd/tui/worker.ts b/packages/opencode/src/cli/cmd/tui/worker.ts
index e63f10ba80c..cc39895aabb 100644
--- a/packages/opencode/src/cli/cmd/tui/worker.ts
+++ b/packages/opencode/src/cli/cmd/tui/worker.ts
@@ -32,6 +32,25 @@ process.on("uncaughtException", (e) => {
   })
 })
 
+// Graceful shutdown on terminal closure or termination
+const workerExit = () => rpc.shutdown().finally(() => process.exit(0))
+process.on("SIGHUP", workerExit)
+process.on("SIGTERM", workerExit)
+
+// Detect parent death as safety net for uncatchable signals (e.g. SIGKILL)
+const ppid = process.ppid
+if (ppid > 1) {
+  const monitor = setInterval(() => {
+    try {
+      process.kill(ppid, 0)
+    } catch {
+      clearInterval(monitor)
+      workerExit()
+    }
+  }, 2000)
+  monitor.unref()
+}
+
 // Subscribe to global events and forward them via RPC
 GlobalBus.on("event", (event) => {
   Rpc.emit("global.event", event)
diff --git a/packages/opencode/src/index.ts b/packages/opencode/src/index.ts
index 6dc5e99e91e..524a2b280b7 100644
--- a/packages/opencode/src/index.ts
+++ b/packages/opencode/src/index.ts
@@ -39,6 +39,12 @@ process.on("uncaughtException", (e) => {
   })
 })
 
+// Safety net: force exit on terminal closure or termination signals.
+// Command-specific handlers (tui, attach, serve) may exit earlier with graceful cleanup.
+const forceExit = () => setTimeout(() => process.exit(0), 3000).unref()
+process.on("SIGHUP", forceExit)
+process.on("SIGTERM", forceExit)
+
 const cli = yargs(hideBin(process.argv))
   .parserConfiguration({ "populate--": true })
   .scriptName("opencode")
diff --git a/packages/opencode/test/cli/signal/signal-handling.test.ts b/packages/opencode/test/cli/signal/signal-handling.test.ts
new file mode 100644
index 00000000000..35d3681f8fc
--- /dev/null
+++ b/packages/opencode/test/cli/signal/signal-handling.test.ts
@@ -0,0 +1,47 @@
+import { describe, test, expect } from "bun:test"
+import path from "path"
+
+const root = path.join(__dirname, "../../..")
+const entry = path.join(root, "src/index.ts")
+
+function spawn(args: string[]) {
+  return Bun.spawn(["bun", "run", "--conditions=browser", entry, ...args], {
+    cwd: root,
+    stdout: "pipe",
+    stderr: "pipe",
+  })
+}
+
+async function alive(pid: number) {
+  try {
+    process.kill(pid, 0)
+    return true
+  } catch {
+    return false
+  }
+}
+
+describe("signal handling", () => {
+  test("serve exits gracefully on SIGHUP", async () => {
+    const proc = spawn(["serve", "--port", "0"])
+    await Bun.sleep(3000)
+    expect(await alive(proc.pid)).toBe(true)
+
+    process.kill(proc.pid, "SIGHUP")
+    const code = await proc.exited
+
+    // Our handler calls process.exit(0). Without it, SIGHUP default gives 129.
+    expect(code).toBe(0)
+  })
+
+  test("serve exits gracefully on SIGTERM", async () => {
+    const proc = spawn(["serve", "--port", "0"])
+    await Bun.sleep(3000)
+    expect(await alive(proc.pid)).toBe(true)
+
+    process.kill(proc.pid, "SIGTERM")
+    const code = await proc.exited
+
+    expect(code).toBe(0)
+  })
+})