diff --git a/CHANGELOG.md b/CHANGELOG.md
index ffb4be2..dde758a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,29 @@
 # Changelog
 
+## [1.6.0] - 2026-02-20
+
+### Fixed
+
+- **#397** - Gemini tool-call payload handling now enforces valid `thought_signature` behavior for `functionCall` parts, preventing `400 INVALID_ARGUMENT` in mixed and parallel call turns.
+
+- **#454** - Request sanitization now removes empty/invalid `contents.parts` entries and invalid `systemInstruction.parts` before forwarding to Antigravity.
+
+- **#444** - Response transform fallback now uses cloned responses and preserves recovery signaling, eliminating `Body already used` failures.
+
+- **#368 (Tackled)** - Claude thinking/signature handling now replaces foreign signatures with sentinels and tightens thinking-order classification to reduce false-positive recovery triggers.
+
+### Changed
+
+- **Debug Sink Split** - `debug` now controls file logging only, while `debug_tui` independently controls TUI panel logging.
+
+- **Header Normalization** - `x-goog-user-project` is now stripped across Antigravity and Gemini CLI request styles.
+
+- **Claude Prompt Auto-Caching (Optional)** - Added `claude_prompt_auto_caching` to inject `cache_control: { type: "ephemeral" }` when Claude prompt caching is desired and unset.
+
+### Documentation
+
+- Updated README, architecture/config/troubleshooting docs, and generated schema docs to reflect new debug sink semantics and config keys.
+
 ## [1.5.2] - 2026-02-18
 
 ### Changed
diff --git a/package.json b/package.json
index 7d8a92c..3adf186 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
     "name": "opencode-antigravity-auth",
-    "version": "1.6.0-beta",
+    "version": "1.6.0",
     "description": "Google Antigravity IDE OAuth auth plugin for Opencode - access Gemini 3 Pro and Claude 4.6 using Google credentials",
     "main": "./dist/index.js",
     "types": "./dist/index.d.ts",