diff --git a/.github/releases/v0.4.0.md b/.github/releases/v0.4.0.md
new file mode 100644
index 0000000..77fd880
--- /dev/null
+++ b/.github/releases/v0.4.0.md
@@ -0,0 +1,38 @@
+0.4.0 uses one H.264 viewer for Android emulators and iOS simulators. Android still uses scrcpy and the device encoder. iOS now uses the simulator helper's native H.264 encoder; the proxy converts AVCC records to Annex-B without decoding or re-encoding video on the host.
+
+## Changed
+
+- Video buffers stay bounded. After dropping dependent frames, playback waits for a keyframe rather than decoding an incomplete sequence.
+- Decoder setup, playback, reset, and terminal disposal have explicit states. Obsolete codec checks and decoder outputs cannot revive a stopped viewer.
+- Capture recovery keeps the device handle and automation session attached. If the capture helper exits, the next stream request restarts capture and rotates the viewer proxy's credentials.
+- Device ownership records now include reservation, attachment, retirement, rollback, and failed cleanup. Failed cleanup keeps ownership reserved, and retries only unfinished steps.
+- Cancelling queued work prevents dispatch. Cancelling running native commands terminates the command before the queue advances; input already sent to the device cannot be undone.
+- Native operations have a 120-second deadline. The RPC deadline allows another 15 seconds for cancellation, cleanup, and returning an outcome. Failures retain whether the action may have executed.
+
+## Fixed
+
+- A capture helper that exits between readiness and publication is rejected instead of being returned as active.
+- Failed initial state publication closes the desktop connection so a fresh connection can retry. Late readiness completion cannot resurrect a closed connection.
+- Failed or ended session-event subscriptions reconnect with cancellable backoff, capped at five seconds.
+- Cleanup after session deletion or movement remains retryable and does not block another session's cleanup.
+- Shutdown intent survives failed cleanup. Physical-device aliases cannot bypass ownership or cause rollback to shut down another session's device.
+- Disposal cancels pending discovery and recovery. Destroyed viewers cannot reconnect or retain decode timers.
+
+Overlapping old tests were consolidated into transition tables, and the previous all-in-one desktop test was split into focused cases. Production function complexity is limited to nine. No runtime dependency or FSM framework was added.
+
+## Update
+
+Update the plugin pin in your global OpenCode configuration, preserving other settings:
+
+```json
+{
+  "$schema": "https://opencode.ai/config.json",
+  "plugins": ["github:viralcodex/opencode-demul#v0.4.0"]
+}
+```
+
+Plugin exports and tool names are unchanged. Android still requires SDK Platform-Tools, Emulator, and a configured AVD. iOS requires Xcode and an iOS Simulator runtime on macOS. Both require Node 22.19+ on the 22.x line, or Node 24+, with npm.
+
+Validation includes lint, formatting, typechecking, 296 passing tests and one existing Bun-only skip, rebuilt bundles, and installed-package loading. Each implementation PR passed Linux CI before merging; lifecycle suites also passed three consecutive local runs. Two fresh helper installations, native module loading, offline reuse, and stale-cache rejection passed on macOS arm64.
+
+Full changelog: https://github.com/viralcodex/opencode-demul/compare/v0.3.0...v0.4.0
diff --git a/README.md b/README.md
index d92a87e..798ce44 100644
--- a/README.md
+++ b/README.md
@@ -23,7 +23,8 @@ Add this entry to your OpenCode configuration.
 
 ```json
 {
-  "plugins": ["github:viralcodex/opencode-demul#v0.3.0"]
+  "$schema": "https://opencode.ai/config.json",
+  "plugins": ["github:viralcodex/opencode-demul#v0.4.0"]
 }
 ```
 
@@ -67,7 +68,7 @@ The first iOS automation command builds the agent's XCTest runner, which can tak
 
 Prebuilt plugin files are included.
 
-[Release notes for v0.3.0](https://github.com/viralcodex/opencode-demul/releases/tag/v0.3.0).
+[Release notes for v0.4.0](https://github.com/viralcodex/opencode-demul/releases/tag/v0.4.0).
 
 ## Development
 
diff --git a/package.json b/package.json
index 8cb84e7..13bbd34 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "$schema": "https://json.schemastore.org/package.json",
   "name": "@opencode/plugin-device",
-  "version": "0.3.0",
+  "version": "0.4.0",
   "description": "Local Android emulator and iOS simulator viewing and session-bound automation for OpenCode Desktop",
   "keywords": [
     "android",