diff --git a/CHANGELOG.md b/CHANGELOG.md
index ce57437..54f0244 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,15 @@
 # Changelog
 
+## v3.10.5 (2026-05-25)
+
+**Context Compaction for Antigravity/Gemini OAuth**
+
+### Fix
+- **Prevent `input token count exceeds maximum` errors** during long conversations
+- Added aggressive compaction policies for Antigravity (`cloudcode-pa`) and Gemini CLI (`googleapis`)
+- Auto-trims old turns when approaching 60% of model context limit (1M tokens for Gemini, 200K for Claude, 128K for GPT-OSS)
+- Added REST model IDs to context size map (`gemini-3-flash`, `gemini-3.1-pro-low`, `claude-sonnet-4-6`, etc.)
+
 ## v3.10.4 (2026-05-25)
 
 **Security: OAuth Secrets Editor + Import JSON**
diff --git a/README.md b/README.md
index d25de49..a39439a 100644
--- a/README.md
+++ b/README.md
@@ -546,6 +546,16 @@ Codex Launcher includes special handling for Gemini 3 / Antigravity OAuth:
 - **User instruction enforcement**: The latest user message is guaranteed to be the
   final content turn sent to Gemini, even after compaction.
 - **Smart compaction**: Old tool outputs capped at 3000 chars, recent 6 at 20000 chars.
+- **Context compaction**: Aggressive auto-trimming when approaching 60% of model context
+  limit (1M tokens Gemini, 200K Claude, 128K GPT-OSS). Prevents token limit errors.
+- **Model ID mapping**: Display names (e.g. `Gemini 3.5 Flash (High)`) mapped to REST API
+  slugs (e.g. `gemini-3-flash`). See `docs/ANTIGRAVITY.md` for details.
+
+### OAuth Secrets
+
+Google OAuth credentials are stored locally in `~/.config/codex-launcher/oauth-secrets.json`
+and never committed to the repository. Use the **OAuth Secrets** button in the launcher
+header to edit or import `client_secret_*.json` files from Google Cloud Console.
 
 ---