diff --git a/README.md b/README.md
index 5746911..564500c 100644
--- a/README.md
+++ b/README.md
@@ -155,10 +155,10 @@ prism gemini -p 'Reply with exactly GEMINI_OK.'
 
 Before each run Prism removes common API-billing environment variables and persistently sets `useG1Credits=false` in Antigravity's shared configuration. If that safety setting cannot be written, Prism fails before launching agy. This disables AI Credit fallback without copying or changing agy's signed-in Google identity. `prism usage` and `prism gemini usage` read the live Antigravity quota through the same official CLI.
 
-The default model is `gemini-3.7-flash-low`. For harder software-engineering or multi-step tool-use tasks, select `gemini-3.1-pro-high` explicitly:
+The default model is the latest subscription model, `gemini-3.8-flash-high`:
 
 ```sh
-prism gemini --model gemini-3.1-pro-high -p 'Review this repository.'
+prism gemini --model gemini-3.8-flash-high -p 'Review this repository.'
 ```
 
 Antigravity CLI must be installed on `PATH`; Prism invokes it internally and keeps `prism gemini` as the user-facing command. When no local session exists, the first `prism gemini` run starts Antigravity's official Google sign-in flow.
diff --git a/internal/cli/gemini.go b/internal/cli/gemini.go
index c8f9ad1..c4c8962 100644
--- a/internal/cli/gemini.go
+++ b/internal/cli/gemini.go
@@ -12,7 +12,7 @@ import (
 	"strings"
 )
 
-const defaultGeminiModel = "gemini-3.7-flash-low"
+const defaultGeminiModel = "gemini-3.8-flash-high"
 
 type geminiCLIExecutable struct {
 	path   string
@@ -182,7 +182,6 @@ or proxies its OAuth tokens. Common API-billing environment variables are
 removed before every run, and useG1Credits=false is persisted before launch
 to disable AI Credit fallback. If no session exists, agy starts its official
 Google sign-in flow automatically.
-The default model is gemini-3.7-flash-low; use --model gemini-3.1-pro-high for
-hard software-engineering and multi-step tool-use work. Other Antigravity CLI
+The default model is gemini-3.8-flash-high. Other Antigravity CLI
 arguments are passed through the Prism surface.`)
 }
diff --git a/internal/cli/gemini_test.go b/internal/cli/gemini_test.go
index 5bde727..09e1334 100644
--- a/internal/cli/gemini_test.go
+++ b/internal/cli/gemini_test.go
@@ -12,8 +12,8 @@ import (
 	"testing"
 )
 
-func TestGeminiDefaultsTo37FlashLowAndPreservesExplicitModel(t *testing.T) {
-	if got := withDefaultGeminiModel([]string{"-p", "hello"}); !reflect.DeepEqual(got, []string{"--model", "gemini-3.7-flash-low", "-p", "hello"}) {
+func TestGeminiDefaultsTo38FlashHighAndPreservesExplicitModel(t *testing.T) {
+	if got := withDefaultGeminiModel([]string{"-p", "hello"}); !reflect.DeepEqual(got, []string{"--model", "gemini-3.8-flash-high", "-p", "hello"}) {
 		t.Fatalf("default args = %#v", got)
 	}
 	for _, args := range [][]string{{"--model", "gemini-3.1-pro-high", "-p", "hard"}, {"-m", "gemini-3.1-pro-high"}, {"--model=gemini-3.1-pro-high"}} {
@@ -28,7 +28,7 @@ func TestGeminiHelpDocumentsAntigravityContract(t *testing.T) {
 	if err := runGeminiCommand(context.Background(), []string{"--help"}, &output, io.Discard); err != nil {
 		t.Fatal(err)
 	}
-	for _, value := range []string{"official Antigravity CLI", "never copies", "API-billing environment", "useG1Credits=false", "sign-in flow automatically", "gemini-3.7-flash-low", "gemini-3.1-pro-high"} {
+	for _, value := range []string{"official Antigravity CLI", "never copies", "API-billing environment", "useG1Credits=false", "sign-in flow automatically", "gemini-3.8-flash-high"} {
 		if !strings.Contains(output.String(), value) {
 			t.Fatalf("help omitted %q: %s", value, output.String())
 		}
@@ -81,7 +81,7 @@ func TestRunAntigravityPassesStreamingAndTimeoutArgumentsAndScrubsAPIKeys(t *tes
 	if err := runAntigravity(context.Background(), geminiCLIExecutable{path: executable}, args, strings.NewReader(""), &output, io.Discard); err != nil {
 		t.Fatal(err)
 	}
-	want := "--model\ngemini-3.7-flash-low\n-p\nhello\n--output-format\nstream-json\n--print-timeout\n30m\n"
+	want := "--model\ngemini-3.8-flash-high\n-p\nhello\n--output-format\nstream-json\n--print-timeout\n30m\n"
 	if output.String() != want {
 		t.Fatalf("output = %q, want %q", output.String(), want)
 	}