diff --git a/crates/plannotator-tui-hosts/src/antigravity.rs b/crates/plannotator-tui-hosts/src/antigravity.rs
index 4ae81a0..cf38900 100644
--- a/crates/plannotator-tui-hosts/src/antigravity.rs
+++ b/crates/plannotator-tui-hosts/src/antigravity.rs
@@ -1,5 +1,5 @@
 //! Antigravity CLI (`agy`): one directory per conversation under the app data directory
-//! (`$ANTIGRAVITY_CLI_HOME`, default `~/.gemini/antigravity-cli`), its steps in
+//! (`$ANTIGRAVITY_CLI_HOME` or `$ANTIGRAVITY_APP_DATA_DIR`, default `~/.gemini/antigravity-cli`), its steps in
 //! `brain/<conversation id>/.system_generated/logs/transcript_full.jsonl`.
 //!
 //! Each line is one step: `USER_INPUT` steps carry the prompt in `content`, `PLANNER_RESPONSE`
diff --git a/crates/plannotator-tui-hosts/src/lib.rs b/crates/plannotator-tui-hosts/src/lib.rs
index 9f01635..bc39ee2 100644
--- a/crates/plannotator-tui-hosts/src/lib.rs
+++ b/crates/plannotator-tui-hosts/src/lib.rs
@@ -41,7 +41,7 @@ pub enum Host {
     /// reports it as `cmd`.
     CommandCode,
     /// Antigravity CLI: `<app data>/brain/<conversation id>/.../transcript_full.jsonl`, the
-    /// app data directory `~/.gemini/antigravity-cli` unless `ANTIGRAVITY_CLI_HOME` moves it;
+    /// app data directory `~/.gemini/antigravity-cli` unless `ANTIGRAVITY_CLI_HOME` or `ANTIGRAVITY_APP_DATA_DIR` moves it;
     /// Herdr reports it as `agy` with the conversation id.
     Antigravity,
 }
diff --git a/crates/plannotator-tui/src/last/roots.rs b/crates/plannotator-tui/src/last/roots.rs
index 5f03223..d00c2c6 100644
--- a/crates/plannotator-tui/src/last/roots.rs
+++ b/crates/plannotator-tui/src/last/roots.rs
@@ -36,7 +36,9 @@ impl Roots {
             codex_home: path("CODEX_HOME").unwrap_or_else(|| home.join(".codex")),
             copilot_home: path("COPILOT_HOME").unwrap_or_else(|| home.join(".copilot")),
             factory_config: path("FACTORY_CONFIG_DIR").unwrap_or_else(|| home.join(".factory")),
+            // agy 1.2.7 reads ANTIGRAVITY_APP_DATA_DIR; ANTIGRAVITY_CLI_HOME is the name reported in #70.
             antigravity_home: path("ANTIGRAVITY_CLI_HOME")
+                .or_else(|| path("ANTIGRAVITY_APP_DATA_DIR"))
                 .unwrap_or_else(|| home.join(antigravity::DEFAULT_APP_DATA_DIR)),
             pi_session_dir: path("PI_CODING_AGENT_SESSION_DIR"),
             pi_agent_dir: path("PI_CODING_AGENT_DIR"),
@@ -108,6 +110,14 @@ mod tests {
 
     use super::*;
 
+    #[test]
+    fn antigravity_app_data_dir_is_honoured() {
+        let roots = Roots::from_lookup(PathBuf::from("home"), |key| {
+            (key == "ANTIGRAVITY_APP_DATA_DIR").then(|| OsString::from("root/agy app"))
+        });
+        assert_eq!(roots.antigravity_home, PathBuf::from("root/agy app"));
+    }
+
     #[test]
     fn every_documented_root_override_is_honoured() {
         let values: HashMap<&str, OsString> = [
diff --git a/docs/decisions.md b/docs/decisions.md
index bc83288..850d95c 100644
--- a/docs/decisions.md
+++ b/docs/decisions.md
@@ -380,7 +380,7 @@ when it runs its own Herdr integration; that id is looked up as `<id>.jsonl`, sl
 first.
 
 **Antigravity CLI** (2026-10-27, herdr-annotate#70). `agy` keeps one directory per
-conversation in its app data directory (`$ANTIGRAVITY_CLI_HOME`, else
+conversation in its app data directory (`$ANTIGRAVITY_CLI_HOME` or `$ANTIGRAVITY_APP_DATA_DIR`, else
 `~/.gemini/antigravity-cli`, `%USERPROFILE%` on Windows):
 `brain/<conversation id>/.system_generated/logs/transcript_full.jsonl`, one step per line.
 `transcript.jsonl` beside it truncates long `content` and is never read. A reply is a