diff --git a/pkg/agent/loop.go b/pkg/agent/loop.go
index 8fd7328d1..1150b5ab3 100644
--- a/pkg/agent/loop.go
+++ b/pkg/agent/loop.go
@@ -980,8 +980,15 @@ func (al *AgentLoop) forceCompression(agent *AgentInstance, sessionKey string) {
 		return
 	}
 
-	// Helper to find the mid-point of the conversation
+	// Find the mid-point of the conversation, avoiding splitting tool call/result pairs.
+	// A tool-call message (role=assistant with ToolCalls) must be followed by its
+	// tool-result message (role=tool). Splitting between them causes API errors.
 	mid := len(conversation) / 2
+	if mid < len(conversation) && mid > 0 {
+		if conversation[mid].Role == "tool" {
+			mid++ // move past the tool result to keep the pair together
+		}
+	}
 
 	// New history structure:
 	// 1. System Prompt (with compression note appended)
diff --git a/pkg/config/migration.go b/pkg/config/migration.go
index 5deb09270..aade11c1b 100644
--- a/pkg/config/migration.go
+++ b/pkg/config/migration.go
@@ -367,7 +367,9 @@ func ConvertProvidersToModelList(cfg *Config) []ModelConfig {
 
 		// Check if this is the user's configured provider
 		if slices.Contains(m.providerNames, userProvider) && userModel != "" {
-			// Use the user's configured model instead of default
+			// Use the user's configured model instead of default.
+			// Also set ModelName so GetModelConfig(userModel) can find this entry.
+			mc.ModelName = userModel
 			mc.Model = buildModelWithProtocol(m.protocol, userModel)
 		} else if userProvider == "" && userModel != "" && !legacyModelNameApplied {
 			// Legacy config: no explicit provider field but model is specified
diff --git a/pkg/providers/openai_compat/provider.go b/pkg/providers/openai_compat/provider.go
index 5dab9b03e..604331185 100644
--- a/pkg/providers/openai_compat/provider.go
+++ b/pkg/providers/openai_compat/provider.go
@@ -289,10 +289,11 @@ func parseResponse(body []byte) (*LLMResponse, error) {
 // It mirrors protocoltypes.Message but omits SystemParts, which is an
 // internal field that would be unknown to third-party endpoints.
 type openaiMessage struct {
-	Role       string     `json:"role"`
-	Content    string     `json:"content"`
-	ToolCalls  []ToolCall `json:"tool_calls,omitempty"`
-	ToolCallID string     `json:"tool_call_id,omitempty"`
+	Role             string     `json:"role"`
+	Content          string     `json:"content"`
+	ReasoningContent string     `json:"reasoning_content,omitempty"`
+	ToolCalls        []ToolCall `json:"tool_calls,omitempty"`
+	ToolCallID       string     `json:"tool_call_id,omitempty"`
 }
 
 // stripSystemParts converts []Message to []openaiMessage, dropping the
@@ -302,10 +303,11 @@ func stripSystemParts(messages []Message) []openaiMessage {
 	out := make([]openaiMessage, len(messages))
 	for i, m := range messages {
 		out[i] = openaiMessage{
-			Role:       m.Role,
-			Content:    m.Content,
-			ToolCalls:  m.ToolCalls,
-			ToolCallID: m.ToolCallID,
+			Role:             m.Role,
+			Content:          m.Content,
+			ReasoningContent: m.ReasoningContent,
+			ToolCalls:        m.ToolCalls,
+			ToolCallID:       m.ToolCallID,
 		}
 	}
 	return out
diff --git a/pkg/tools/shell.go b/pkg/tools/shell.go
index b52433b6f..3c671aed2 100644
--- a/pkg/tools/shell.go
+++ b/pkg/tools/shell.go
@@ -28,7 +28,7 @@ var defaultDenyPatterns = []*regexp.Regexp{
 	regexp.MustCompile(`\brm\s+-[rf]{1,2}\b`),
 	regexp.MustCompile(`\bdel\s+/[fq]\b`),
 	regexp.MustCompile(`\brmdir\s+/s\b`),
-	regexp.MustCompile(`\b(format|mkfs|diskpart)\b\s`), // Match disk wiping commands (must be followed by space/args)
+	regexp.MustCompile(`(?:^|\s)(format|mkfs|diskpart)\s`), // Match disk wiping commands, avoid matching --format flags
 	regexp.MustCompile(`\bdd\s+if=`),
 	regexp.MustCompile(`>\s*/dev/sd[a-z]\b`), // Block writes to disk devices (but allow /dev/null)
 	regexp.MustCompile(`\b(shutdown|reboot|poweroff)\b`),
@@ -287,10 +287,11 @@ func (t *ExecTool) guardCommand(command, cwd string) string {
 			return ""
 		}
 
-		pathPattern := regexp.MustCompile(`[A-Za-z]:\\[^\\\"']+|/[^\s\"']+`)
-		matches := pathPattern.FindAllString(cmd, -1)
+		pathPattern := regexp.MustCompile(`(?:^|\s)([A-Za-z]:\\[^\\"']+|/[a-zA-Z][^\s"']*)`)
+		matches := pathPattern.FindAllStringSubmatch(cmd, -1)
 
-		for _, raw := range matches {
+		for _, match := range matches {
+			raw := match[1]
 			p, err := filepath.Abs(raw)
 			if err != nil {
 				continue