diff --git a/CHANGLOG.md b/CHANGLOG.md
index 2cbdf1b..1e43543 100644
--- a/CHANGLOG.md
+++ b/CHANGLOG.md
@@ -1,3 +1,7 @@
+## [0.1.16] - 2025-11-10
+### Fixed
+- fix baggage escape problem
+
 ## [0.1.15] - 2025-10-23
 ### Added
 - support set spanID when StartSpan
diff --git a/internal/trace/span.go b/internal/trace/span.go
index fe467d9..e1e7099 100644
--- a/internal/trace/span.go
+++ b/internal/trace/span.go
@@ -742,10 +742,10 @@ func (s *Span) SetBaggage(ctx context.Context, baggageItems map[string]string) {
 		return
 	}
 
-	s.setBaggage(ctx, baggageItems, true)
+	s.setBaggage(ctx, baggageItems)
 }
 
-func (s *Span) setBaggage(ctx context.Context, baggageItems map[string]string, escape bool) {
+func (s *Span) setBaggage(ctx context.Context, baggageItems map[string]string) {
 	if s == nil {
 		return
 	}
@@ -760,10 +760,6 @@ func (s *Span) setBaggage(ctx context.Context, baggageItems map[string]string, e
 			s.SetTags(ctx, map[string]interface{}{key: value})
 			newKey := key
 			newValue := value
-			if escape {
-				newKey = url.QueryEscape(key)
-				newValue = url.QueryEscape(value)
-			}
 			s.SetBaggageItem(newKey, newValue)
 		}
 	}
@@ -928,7 +924,7 @@ func (s *Span) toHeaderBaggage() (string, error) {
 		tempV := v
 		// empty key or value is invalid
 		if tempK != "" && tempV != "" {
-			m[tempK] = tempV
+			m[url.QueryEscape(tempK)] = url.QueryEscape(tempV)
 		}
 	}
 	return util.MapToStringString(m), nil
diff --git a/internal/trace/trace.go b/internal/trace/trace.go
index c73f258..6e7f806 100644
--- a/internal/trace/trace.go
+++ b/internal/trace/trace.go
@@ -190,7 +190,7 @@ func (t *Provider) startSpan(ctx context.Context, spanName string, spanType stri
 	}
 
 	// 3. set Baggage from parent span
-	s.setBaggage(ctx, options.Baggage, false)
+	s.setBaggage(ctx, options.Baggage)
 
 	return s
 }
diff --git a/internal/version.go b/internal/version.go
index 9cd80d7..8e0c3ac 100644
--- a/internal/version.go
+++ b/internal/version.go
@@ -5,5 +5,5 @@ package internal
 
 // Version returns the version of the loop package.
 func Version() string {
-	return "v0.1.15"
+	return "v0.1.16"
 }
diff --git a/spec/tracespec/model.go b/spec/tracespec/model.go
index f4a93bc..c5b5d4c 100644
--- a/spec/tracespec/model.go
+++ b/spec/tracespec/model.go
@@ -7,13 +7,15 @@ import "encoding/json"
 
 // ModelInput is the input for model span, for tag key: input
 type ModelInput struct {
-	Messages        []*ModelMessage  `json:"messages,omitempty"`
-	Tools           []*ModelTool     `json:"tools,omitempty"`
-	ModelToolChoice *ModelToolChoice `json:"tool_choice,omitempty"`
+	Messages           []*ModelMessage  `json:"messages,omitempty"`
+	Tools              []*ModelTool     `json:"tools,omitempty"`
+	ModelToolChoice    *ModelToolChoice `json:"tool_choice,omitempty"`
+	PreviousResponseID string           `json:"previous_response_id,omitempty"`
 }
 
 // ModelOutput is the output for model span, for tag key: output
 type ModelOutput struct {
+	ID      string         `json:"id,omitempty"`
 	Choices []*ModelChoice `json:"choices"`
 }