diff --git a/sdk/api/handlers/handlers.go b/sdk/api/handlers/handlers.go
index 1fda8f49f..369ab5a8d 100644
--- a/sdk/api/handlers/handlers.go
+++ b/sdk/api/handlers/handlers.go
@@ -211,6 +211,19 @@ func requestExecutionMetadata(ctx context.Context) map[string]any {
 	return meta
 }
 
+// headersFromContext extracts the original HTTP request headers from the gin context
+// embedded in the provided context. This allows session affinity selectors to read
+// client headers like X-Amp-Thread-Id.
+func headersFromContext(ctx context.Context) http.Header {
+	if ctx == nil {
+		return nil
+	}
+	if ginCtx, ok := ctx.Value("gin").(*gin.Context); ok && ginCtx != nil && ginCtx.Request != nil {
+		return ginCtx.Request.Header.Clone()
+	}
+	return nil
+}
+
 func pinnedAuthIDFromContext(ctx context.Context) string {
 	if ctx == nil {
 		return ""
@@ -488,6 +501,7 @@ func (h *BaseAPIHandler) ExecuteWithAuthManager(ctx context.Context, handlerType
 		Alt:             alt,
 		OriginalRequest: rawJSON,
 		SourceFormat:    sdktranslator.FromString(handlerType),
+		Headers:         headersFromContext(ctx),
 	}
 	opts.Metadata = reqMeta
 	resp, err := h.AuthManager.Execute(ctx, providers, req, opts)
@@ -535,6 +549,7 @@ func (h *BaseAPIHandler) ExecuteCountWithAuthManager(ctx context.Context, handle
 		Alt:             alt,
 		OriginalRequest: rawJSON,
 		SourceFormat:    sdktranslator.FromString(handlerType),
+		Headers:         headersFromContext(ctx),
 	}
 	opts.Metadata = reqMeta
 	resp, err := h.AuthManager.ExecuteCount(ctx, providers, req, opts)
@@ -586,6 +601,7 @@ func (h *BaseAPIHandler) ExecuteStreamWithAuthManager(ctx context.Context, handl
 		Alt:             alt,
 		OriginalRequest: rawJSON,
 		SourceFormat:    sdktranslator.FromString(handlerType),
+		Headers:         headersFromContext(ctx),
 	}
 	opts.Metadata = reqMeta
 	streamResult, err := h.AuthManager.ExecuteStream(ctx, providers, req, opts)