diff --git a/pkg/agent/loop.go b/pkg/agent/loop.go
index 11f9438c2..e188ad2d5 100644
--- a/pkg/agent/loop.go
+++ b/pkg/agent/loop.go
@@ -2852,7 +2852,7 @@ func (al *AgentLoop) resolveContextManager() ContextManager {
 		})
 		return &legacyContextManager{al: al}
 	}
-	cm, err := factory(nil, al)
+	cm, err := factory(al.cfg.Agents.Defaults.ContextManagerConfig, al)
 	if err != nil {
 		logger.WarnCF("agent", "Failed to create context manager, falling back to legacy", map[string]any{
 			"name":  name,
diff --git a/pkg/config/config.go b/pkg/config/config.go
index 5d6106d39..da7a197e4 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -226,27 +226,28 @@ type ToolFeedbackConfig struct {
 }
 
 type AgentDefaults struct {
-	Workspace                 string             `json:"workspace"                       env:"PICOCLAW_AGENTS_DEFAULTS_WORKSPACE"`
-	RestrictToWorkspace       bool               `json:"restrict_to_workspace"           env:"PICOCLAW_AGENTS_DEFAULTS_RESTRICT_TO_WORKSPACE"`
-	AllowReadOutsideWorkspace bool               `json:"allow_read_outside_workspace"    env:"PICOCLAW_AGENTS_DEFAULTS_ALLOW_READ_OUTSIDE_WORKSPACE"`
-	Provider                  string             `json:"provider"                        env:"PICOCLAW_AGENTS_DEFAULTS_PROVIDER"`
-	ModelName                 string             `json:"model_name"                      env:"PICOCLAW_AGENTS_DEFAULTS_MODEL_NAME"`
+	Workspace                 string             `json:"workspace"                        env:"PICOCLAW_AGENTS_DEFAULTS_WORKSPACE"`
+	RestrictToWorkspace       bool               `json:"restrict_to_workspace"            env:"PICOCLAW_AGENTS_DEFAULTS_RESTRICT_TO_WORKSPACE"`
+	AllowReadOutsideWorkspace bool               `json:"allow_read_outside_workspace"     env:"PICOCLAW_AGENTS_DEFAULTS_ALLOW_READ_OUTSIDE_WORKSPACE"`
+	Provider                  string             `json:"provider"                         env:"PICOCLAW_AGENTS_DEFAULTS_PROVIDER"`
+	ModelName                 string             `json:"model_name"                       env:"PICOCLAW_AGENTS_DEFAULTS_MODEL_NAME"`
 	ModelFallbacks            []string           `json:"model_fallbacks,omitempty"`
-	ImageModel                string             `json:"image_model,omitempty"           env:"PICOCLAW_AGENTS_DEFAULTS_IMAGE_MODEL"`
+	ImageModel                string             `json:"image_model,omitempty"            env:"PICOCLAW_AGENTS_DEFAULTS_IMAGE_MODEL"`
 	ImageModelFallbacks       []string           `json:"image_model_fallbacks,omitempty"`
-	MaxTokens                 int                `json:"max_tokens"                      env:"PICOCLAW_AGENTS_DEFAULTS_MAX_TOKENS"`
-	ContextWindow             int                `json:"context_window,omitempty"        env:"PICOCLAW_AGENTS_DEFAULTS_CONTEXT_WINDOW"`
-	Temperature               *float64           `json:"temperature,omitempty"           env:"PICOCLAW_AGENTS_DEFAULTS_TEMPERATURE"`
-	MaxToolIterations         int                `json:"max_tool_iterations"             env:"PICOCLAW_AGENTS_DEFAULTS_MAX_TOOL_ITERATIONS"`
-	SummarizeMessageThreshold int                `json:"summarize_message_threshold"     env:"PICOCLAW_AGENTS_DEFAULTS_SUMMARIZE_MESSAGE_THRESHOLD"`
-	SummarizeTokenPercent     int                `json:"summarize_token_percent"         env:"PICOCLAW_AGENTS_DEFAULTS_SUMMARIZE_TOKEN_PERCENT"`
-	MaxMediaSize              int                `json:"max_media_size,omitempty"        env:"PICOCLAW_AGENTS_DEFAULTS_MAX_MEDIA_SIZE"`
+	MaxTokens                 int                `json:"max_tokens"                       env:"PICOCLAW_AGENTS_DEFAULTS_MAX_TOKENS"`
+	ContextWindow             int                `json:"context_window,omitempty"         env:"PICOCLAW_AGENTS_DEFAULTS_CONTEXT_WINDOW"`
+	Temperature               *float64           `json:"temperature,omitempty"            env:"PICOCLAW_AGENTS_DEFAULTS_TEMPERATURE"`
+	MaxToolIterations         int                `json:"max_tool_iterations"              env:"PICOCLAW_AGENTS_DEFAULTS_MAX_TOOL_ITERATIONS"`
+	SummarizeMessageThreshold int                `json:"summarize_message_threshold"      env:"PICOCLAW_AGENTS_DEFAULTS_SUMMARIZE_MESSAGE_THRESHOLD"`
+	SummarizeTokenPercent     int                `json:"summarize_token_percent"          env:"PICOCLAW_AGENTS_DEFAULTS_SUMMARIZE_TOKEN_PERCENT"`
+	MaxMediaSize              int                `json:"max_media_size,omitempty"         env:"PICOCLAW_AGENTS_DEFAULTS_MAX_MEDIA_SIZE"`
 	Routing                   *RoutingConfig     `json:"routing,omitempty"`
-	SteeringMode              string             `json:"steering_mode,omitempty"         env:"PICOCLAW_AGENTS_DEFAULTS_STEERING_MODE"` // "one-at-a-time" (default) or "all"
-	SubTurn                   SubTurnConfig      `json:"subturn"                                                                                     envPrefix:"PICOCLAW_AGENTS_DEFAULTS_SUBTURN_"`
+	SteeringMode              string             `json:"steering_mode,omitempty"          env:"PICOCLAW_AGENTS_DEFAULTS_STEERING_MODE"` // "one-at-a-time" (default) or "all"
+	SubTurn                   SubTurnConfig      `json:"subturn"                                                                                      envPrefix:"PICOCLAW_AGENTS_DEFAULTS_SUBTURN_"`
 	ToolFeedback              ToolFeedbackConfig `json:"tool_feedback,omitempty"`
-	SplitOnMarker             bool               `json:"split_on_marker"                 env:"PICOCLAW_AGENTS_DEFAULTS_SPLIT_ON_MARKER"` // split messages on <|[SPLIT]|> marker
-	ContextManager            string             `json:"context_manager,omitempty"       env:"PICOCLAW_AGENTS_DEFAULTS_CONTEXT_MANAGER"`
+	SplitOnMarker             bool               `json:"split_on_marker"                  env:"PICOCLAW_AGENTS_DEFAULTS_SPLIT_ON_MARKER"` // split messages on <|[SPLIT]|> marker
+	ContextManager            string             `json:"context_manager,omitempty"        env:"PICOCLAW_AGENTS_DEFAULTS_CONTEXT_MANAGER"`
+	ContextManagerConfig      json.RawMessage    `json:"context_manager_config,omitempty" env:"PICOCLAW_AGENTS_DEFAULTS_CONTEXT_MANAGER_CONFIG"`
 }
 
 const DefaultMaxMediaSize = 20 * 1024 * 1024 // 20 MB