diff --git a/config/backends/backend-instances/agy-cli-acp.default.yaml b/config/backends/backend-instances/agy-cli-acp.default.yaml
index a56cb5620..c33d350cf 100644
--- a/config/backends/backend-instances/agy-cli-acp.default.yaml
+++ b/config/backends/backend-instances/agy-cli-acp.default.yaml
@@ -6,7 +6,9 @@ connector: agy-cli-acp
 extra:
   # workspace_path omitted: project root comes from session auto-detection (per-request project_dir).
   model: "auto"
-  process_timeout: 300
+  # 4 hours. Forwarded to the wrapper as --timeout-seconds (agy --print-timeout).
+  # agy's own print-mode default is 5 minutes and will abort long tool waits.
+  process_timeout: 14400
   idle_timeout: 120
   skip_permissions: true
   mcp_servers: []
diff --git a/src/connectors/agy_cli_acp.py b/src/connectors/agy_cli_acp.py
index b34cb10b3..d5d6ae844 100644
--- a/src/connectors/agy_cli_acp.py
+++ b/src/connectors/agy_cli_acp.py
@@ -27,6 +27,10 @@
 logger = logging.getLogger(__name__)
 
 ACP_PROTOCOL_VERSION = 1
+# Match go-agy-acp-wrapper's 4-hour per-turn ceiling. This is both the ACP
+# JSON-RPC wait and --timeout-seconds forwarded to the wrapper; agy's own
+# --print-timeout default is only 5 minutes.
+DEFAULT_AGY_PROCESS_TIMEOUT_SECONDS = 14400.0
 CANONICAL_MODEL_ID_PATTERN = re.compile(
     r"^[a-z0-9][a-z0-9._-]*/[a-zA-Z0-9][a-zA-Z0-9._-]*$"
 )
@@ -296,6 +300,7 @@ def __init__(
         self._skip_permissions = True
         self._mcp_servers: list[Any] = []
         self._extra_wrapper_args: list[str] = []
+        self._process_timeout = DEFAULT_AGY_PROCESS_TIMEOUT_SECONDS
 
     async def initialize(self, **kwargs: Any) -> None:
         try:
diff --git a/tests/unit/connectors/test_agy_cli_acp.py b/tests/unit/connectors/test_agy_cli_acp.py
index 73e607e99..9b2498609 100644
--- a/tests/unit/connectors/test_agy_cli_acp.py
+++ b/tests/unit/connectors/test_agy_cli_acp.py
@@ -9,6 +9,7 @@
 from pydantic.types import JsonValue
 from src.connectors.acp_core.types import ACPNotification
 from src.connectors.agy_cli_acp import (
+    DEFAULT_AGY_PROCESS_TIMEOUT_SECONDS,
     AgyCliAcpConnector,
     AgyCliConfiguredModelEnumerator,
     build_agy_acp_wrapper_command,
@@ -172,6 +173,12 @@ def test_resolve_wrapper_prefers_existing_file(self, tmp_path: Path) -> None:
         exe.write_text("noop", encoding="utf-8")
         assert resolve_agy_acp_wrapper_executable(str(exe)) == str(exe.resolve())
 
+    def test_connector_default_process_timeout_is_four_hours(
+        self, connector: AgyCliAcpConnector
+    ) -> None:
+        assert connector._process_timeout == DEFAULT_AGY_PROCESS_TIMEOUT_SECONDS
+        assert DEFAULT_AGY_PROCESS_TIMEOUT_SECONDS == 14400.0
+
 
 class TestAgyCliAcpInitialization:
     async def test_initialize_with_project_dir(
@@ -190,6 +197,7 @@ async def test_initialize_with_project_dir(
         assert connector.is_backend_functional() is True
         assert connector._default_project_dir == temp_workspace.resolve()
         assert connector._model == "google/gemini-3.5-flash-medium"
+        assert connector._process_timeout == DEFAULT_AGY_PROCESS_TIMEOUT_SECONDS
 
     async def test_initialize_requires_existing_workspace(
         self, connector: AgyCliAcpConnector, tmp_path: Path