From 48a4201f40c475f54461600fe1f6946ccd462b42 Mon Sep 17 00:00:00 2001
From: Stephen Chin <1290231+steveonjava@users.noreply.github.com>
Date: Wed, 26 Aug 2026 03:39:58 -0700
Subject: [PATCH] fix(compaction): preserve switch compatibility fixtures

Keep model-switch callers compatible with result objects created before runtime_capabilities was added, and do not roll back minimal agents that lack optional LM Studio helpers. Preserve rollback for real helper failures.
---
 agent/agent_runtime_helpers.py | 33 +++++++++++++++++++++------------
 cli.py                         |  8 +++++---
 gateway/slash_commands.py      |  6 ++++--
 tui_gateway/server.py          |  2 +-
 4 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/agent/agent_runtime_helpers.py b/agent/agent_runtime_helpers.py
index 6a2e0f2b8d..c5eb9b34fc 100644
--- a/agent/agent_runtime_helpers.py
+++ b/agent/agent_runtime_helpers.py
@@ -3227,23 +3227,32 @@ def switch_model(
     except Exception:
         _destination_context_intent = None
     agent._config_context_length = _destination_context_intent
-    try:
-        _runtime_context_length = agent._ensure_lmstudio_runtime_loaded(
-            _destination_context_intent
-        )
-    except Exception:
-        _restore_snapshot()
-        raise
-    if agent._lmstudio_load_was_unverified(_runtime_context_length):
+    if hasattr(agent, "_ensure_lmstudio_runtime_loaded"):
+        try:
+            _runtime_context_length = agent._ensure_lmstudio_runtime_loaded(
+                _destination_context_intent
+            )
+        except Exception:
+            _restore_snapshot()
+            raise
+    else:
+        _runtime_context_length = None
+    if (
+        hasattr(agent, "_lmstudio_load_was_unverified")
+        and agent._lmstudio_load_was_unverified(_runtime_context_length)
+    ):
         logger.warning(
             "LM Studio model activation was rejected or completed without a "
             "verifiable active context length during model switch; continuing "
             "with configured context"
         )
-    _effective_context_length = agent._effective_lmstudio_context_length(
-        _destination_context_intent,
-        _runtime_context_length,
-    )
+    if hasattr(agent, "_effective_lmstudio_context_length"):
+        _effective_context_length = agent._effective_lmstudio_context_length(
+            _destination_context_intent,
+            _runtime_context_length,
+        )
+    else:
+        _effective_context_length = _destination_context_intent
 
     # ── Re-evaluate prompt caching ──
     # Refresh the custom-provider snapshot from the config just loaded above
diff --git a/cli.py b/cli.py
index f92fd5d4cb..256e3b23e0 100644
--- a/cli.py
+++ b/cli.py
@@ -10306,7 +10306,9 @@ class HermesCLI(CLIAgentSetupMixin, CLICommandsMixin, CLIBillingMixin):
                             api_key=_reset_result.api_key,
                             base_url=_reset_result.base_url,
                             api_mode=_reset_result.api_mode,
-                            capabilities=_reset_result.runtime_capabilities,
+                            capabilities=getattr(
+                                _reset_result, "runtime_capabilities", None
+                            ),
                         )
                     self.model = _reset_result.new_model
                     self.provider = _reset_result.target_provider
@@ -11626,7 +11628,7 @@ class HermesCLI(CLIAgentSetupMixin, CLICommandsMixin, CLIBillingMixin):
                     api_key=result.api_key,
                     base_url=result.base_url,
                     api_mode=result.api_mode,
-                    capabilities=result.runtime_capabilities,
+                    capabilities=getattr(result, "runtime_capabilities", None),
                 )
             except Exception as exc:
                 # The agent rolled itself back to the old working model/client.
@@ -12017,7 +12019,7 @@ class HermesCLI(CLIAgentSetupMixin, CLICommandsMixin, CLIBillingMixin):
                     api_key=result.api_key,
                     base_url=result.base_url,
                     api_mode=result.api_mode,
-                    capabilities=result.runtime_capabilities,
+                    capabilities=getattr(result, "runtime_capabilities", None),
                 )
             except Exception as exc:
                 # Agent rolled itself back; roll the CLI back too and abort so a
diff --git a/gateway/slash_commands.py b/gateway/slash_commands.py
index b8ce7cc616..627ff37f0e 100644
--- a/gateway/slash_commands.py
+++ b/gateway/slash_commands.py
@@ -1950,7 +1950,9 @@ class GatewaySlashCommandsMixin:
                                     api_key=result.api_key,
                                     base_url=result.base_url,
                                     api_mode=result.api_mode,
-                                    capabilities=result.runtime_capabilities,
+                                    capabilities=getattr(
+                                        result, "runtime_capabilities", None
+                                    ),
                                 )
                             except Exception as exc:
                                 # The in-place swap rolled the agent back to the
@@ -2265,7 +2267,7 @@ class GatewaySlashCommandsMixin:
                         api_key=result.api_key,
                         base_url=result.base_url,
                         api_mode=result.api_mode,
-                        capabilities=result.runtime_capabilities,
+                        capabilities=getattr(result, "runtime_capabilities", None),
                     )
                 except Exception as exc:
                     # In-place swap rolled the agent back to the OLD working
diff --git a/tui_gateway/server.py b/tui_gateway/server.py
index e4b70649ea..8fc646a377 100644
--- a/tui_gateway/server.py
+++ b/tui_gateway/server.py
@@ -6348,7 +6348,7 @@ def _apply_model_switch(
                 api_key=result.api_key,
                 base_url=result.base_url,
                 api_mode=result.api_mode,
-                capabilities=result.runtime_capabilities,
+                capabilities=getattr(result, "runtime_capabilities", None),
             )
         except Exception as exc:
             # The in-place swap rolled the agent back to the old working