diff --git a/apps/daemon/src/app-config.ts b/apps/daemon/src/app-config.ts
index 0c2c8356dfc..53afb690fc3 100644
--- a/apps/daemon/src/app-config.ts
+++ b/apps/daemon/src/app-config.ts
@@ -200,6 +200,7 @@ const AGENT_CLI_ENV_KEYS: ReadonlyMap<string, ReadonlySet<string>> = new Map([
     'OPENCODE_TEST_HOME',
   ])],
   ['aider', new Set(['AIDER_BIN'])],
+  ['antigravity', new Set(['AGY_BIN'])],
   ['claude', new Set(['CLAUDE_CONFIG_DIR', 'CLAUDE_BIN', 'ANTHROPIC_BASE_URL', 'ANTHROPIC_API_KEY', 'ANTHROPIC_AUTH_TOKEN', 'MMD_MODEL_ROUTES_FILE'])],
   ['codex', new Set(['CODEX_HOME', 'CODEX_BIN', 'OPENAI_BASE_URL', 'CODEX_API_KEY', 'OPENAI_API_KEY'])],
   ['copilot', new Set(['COPILOT_BIN'])],
diff --git a/apps/daemon/src/runtimes/defs/antigravity.ts b/apps/daemon/src/runtimes/defs/antigravity.ts
index 58e89cecd9b..f55a5291799 100644
--- a/apps/daemon/src/runtimes/defs/antigravity.ts
+++ b/apps/daemon/src/runtimes/defs/antigravity.ts
@@ -215,18 +215,6 @@ export const antigravityAgentDef = {
         runtimeContext.antigravitySettingsPath,
       );
     }
-    // We invoke agy via `-p -` (print mode + stdin sentinel), NOT
-    // `chat -`. Verified against `agy --help` on v1.0.3 — the
-    // `Available subcommands` list is `changelog / help / install /
-    // plugin / update`, and `chat` is NOT among them. `-p` is the
-    // documented print-mode flag (`Short alias for --print`) and
-    // `agy -p -` reads the prompt from stdin. The looper reviewer
-    // bot's environment runs a different agy build that may have
-    // renamed the entry point; until upstream confirms a stable
-    // headless subcommand (see google-antigravity/antigravity-cli#119)
-    // and the change actually ships in the auto-update channel that
-    // packaged OD users get, `-p -` is the contract that actually
-    // produces a print-mode reply on the installed CLI.
     const args: string[] = [];
     // Always opt into `--log-file` when the daemon supplied a path so
     // it can post-exit grep for the actual upstream failure shape
@@ -235,16 +223,9 @@ export const antigravityAgentDef = {
     // never echoes those errors on stdout. See server.ts empty-output
     // guard for the consumer.
     //
-    // Flag order is load-bearing on agy v1.0.3: `agy -p --log-file
-    // /tmp/x -` runs successfully but leaves /tmp/x empty, while `agy
-    // --log-file /tmp/x -p -` captures the diagnostic log, including
-    // `Propagating selected model override to backend: label="<model>"`
-    // and auth/quota failures.
     if (runtimeContext.agentLogFilePath) {
       args.push('--log-file', runtimeContext.agentLogFilePath);
     }
-    args.push('-p');
-    args.push('-');
     return args;
   },
   promptViaStdin: true,
diff --git a/apps/daemon/src/runtimes/executables.ts b/apps/daemon/src/runtimes/executables.ts
index a9b3c46adff..126aea02bd1 100644
--- a/apps/daemon/src/runtimes/executables.ts
+++ b/apps/daemon/src/runtimes/executables.ts
@@ -16,6 +16,7 @@ const RUNTIME_PROJECT_ROOT = path.resolve(
 const AGENT_BIN_ENV_KEYS = new Map<string, string>([
   ['amr', 'VELA_BIN'],
   ['aider', 'AIDER_BIN'],
+  ['antigravity', 'AGY_BIN'],
   ['claude', 'CLAUDE_BIN'],
   ['codebuddy', 'CODEBUDDY_BIN'],
   ['codex', 'CODEX_BIN'],
diff --git a/apps/daemon/tests/runtimes/agent-args.test.ts b/apps/daemon/tests/runtimes/agent-args.test.ts
index 7ea22fe079b..135ea84b5c7 100644
--- a/apps/daemon/tests/runtimes/agent-args.test.ts
+++ b/apps/daemon/tests/runtimes/agent-args.test.ts
@@ -534,18 +534,18 @@ test('qwen args check promptViaStdin, base args, model args and exclude `-` sent
 // the daemon would render the resulting empty reply as a "successful"
 // agent response — exactly the failure mode the auth/quota guard at
 // server.ts ~12090 is meant to catch but for the wrong reason.
-test('antigravity pipes prompt via stdin via -p flag (print mode)', () => {
+test('antigravity uses STDIN for the prompt instead of the legacy -p flag', () => {
   assert.equal(antigravity.bin, 'agy');
   assert.equal(antigravity.streamFormat, 'plain');
   assert.equal(antigravity.promptViaStdin, true);
 
   const args = antigravity.buildArgs('write hello world', [], [], {}, {});
-  assert.deepEqual(args, ['-p', '-']);
+  assert.deepEqual(args, []);
 
   const argsWithLog = antigravity.buildArgs('write hello world', [], [], {}, {
     agentLogFilePath: '/tmp/od-agy-test.log',
   });
-  assert.deepEqual(argsWithLog, ['--log-file', '/tmp/od-agy-test.log', '-p', '-']);
+  assert.deepEqual(argsWithLog, ['--log-file', '/tmp/od-agy-test.log']);
 
   // No `--model` flag exists upstream, so buildArgs argv must stay the
   // same regardless of which label the user picks.
@@ -560,7 +560,7 @@ test('antigravity pipes prompt via stdin via -p flag (print mode)', () => {
       antigravitySettingsPath: join(settingsDir, 'settings.json'),
     });
     assert.equal(withModel.includes('--model'), false);
-    assert.deepEqual(withModel, ['--log-file', '/tmp/od-agy-test.log', '-p', '-']);
+    assert.deepEqual(withModel, ['--log-file', '/tmp/od-agy-test.log']);
   } finally {
     rmSync(settingsDir, { recursive: true, force: true });
   }
@@ -576,13 +576,13 @@ test('antigravity pipes prompt via stdin via -p flag (print mode)', () => {
   const followUp = antigravity.buildArgs('next message', [], [], {}, {
     hasPriorAssistantTurn: true,
   });
-  assert.deepEqual(followUp, ['-p', '-']);
+  assert.deepEqual(followUp, []);
   assert.equal(followUp.includes('-c'), false);
 
   const firstTurn = antigravity.buildArgs('first', [], [], {}, {
     hasPriorAssistantTurn: false,
   });
-  assert.deepEqual(firstTurn, ['-p', '-']);
+  assert.deepEqual(firstTurn, []);
   assert.equal(antigravity.resumesSessionViaCli, undefined);
 
   assert.equal(antigravity.maxPromptArgBytes, undefined);