diff --git a/include/xo/reader2/ParserStateMachine.hpp b/include/xo/reader2/ParserStateMachine.hpp
index d065e24f..89569695 100644
--- a/include/xo/reader2/ParserStateMachine.hpp
+++ b/include/xo/reader2/ParserStateMachine.hpp
@@ -36,6 +36,7 @@ namespace xo {
             using AAllocator = xo::mm::AAllocator;
             using ArenaConfig = xo::mm::ArenaConfig;
             using DArena = xo::mm::DArena;
+            using MemorySizeInfo = xo::mm::MemorySizeInfo;
             using size_type = std::size_t;
 
         public:
@@ -61,6 +62,11 @@ namespace xo {
             /** top of parser stack **/
             obj<ASyntaxStateMachine> top_ssm() const;
 
+            /** number of distinct memory pools owned by PS **/
+            std::size_t _n_store() const noexcept;
+            /** memory consumption for i'th memory pool **/
+            MemorySizeInfo _store_info(std::size_t i) const noexcept;
+
             ///@}
 
             /** @defgroup scm-parserstatemachine-bookkeeping bookkeeping methods **/
diff --git a/include/xo/reader2/SchematikaParser.hpp b/include/xo/reader2/SchematikaParser.hpp
index 7be74aa5..83e9230b 100644
--- a/include/xo/reader2/SchematikaParser.hpp
+++ b/include/xo/reader2/SchematikaParser.hpp
@@ -156,6 +156,7 @@ namespace xo {
             using token_type = Token;
             using ArenaConfig = xo::mm::ArenaConfig;
             using AAllocator = xo::mm::AAllocator;
+            using MemorySizeInfo = xo::mm::MemorySizeInfo;
             using ppindentinfo = xo::print::ppindentinfo;
             using size_type = std::size_t;
 
@@ -192,6 +193,11 @@ namespace xo {
             /** top of parser stack **/
             obj<ASyntaxStateMachine> top_ssm() const;
 
+            /** number of distinct memory pools owned by PS **/
+            std::size_t _n_store() const noexcept;
+            /** memory consumption for i'th memory pool **/
+            MemorySizeInfo _store_info(std::size_t i) const noexcept;
+
             ///@}
             /** scm-schematikaparser-general-methods **/
             ///@{
diff --git a/include/xo/reader2/SchematikaReader.hpp b/include/xo/reader2/SchematikaReader.hpp
index fd26a4ec..3c2b5312 100644
--- a/include/xo/reader2/SchematikaReader.hpp
+++ b/include/xo/reader2/SchematikaReader.hpp
@@ -36,6 +36,7 @@ namespace xo {
         class SchematikaReader {
         public:
             using AAllocator = xo::mm::AAllocator;
+            using MemorySizeInfo = xo::mm::MemorySizeInfo;
             using span_type = xo::mm::span<const char>;
             using size_type = std::size_t;
 
@@ -43,6 +44,9 @@ namespace xo {
             SchematikaReader(const ReaderConfig & config,
                              obj<AAllocator> expr_alloc);
 
+            std::size_t _n_store() const noexcept;
+            MemorySizeInfo _store_info(std::size_t i) const noexcept;
+
             /** true iff parser is at top-level.
              *  false iff parser is working on incomplete expression
              **/
@@ -53,6 +57,11 @@ namespace xo {
              **/
             void begin_interactive_session();
 
+            /** prepare batch session
+             *  (limits expression types at toplevel)
+             **/
+            void begin_batch_session();
+
             /** consume input @p input_cstr **/
             const ReaderResult & read_expr(span_type input_span, bool eof);
 
diff --git a/src/reader2/ParserStateMachine.cpp b/src/reader2/ParserStateMachine.cpp
index cf9c26c1..ff845762 100644
--- a/src/reader2/ParserStateMachine.cpp
+++ b/src/reader2/ParserStateMachine.cpp
@@ -16,6 +16,7 @@
 #include <stdexcept>
 
 namespace xo {
+    using xo::mm::MemorySizeInfo;
     using xo::print::APrintable;
     using xo::facet::FacetRegistry;
     using xo::facet::with_facet;
@@ -53,6 +54,29 @@ namespace xo {
             return this->stack_->top();
         }
 
+        std::size_t
+        ParserStateMachine::_n_store() const noexcept
+        {
+            return stringtable_._n_store() + 1;
+        }
+
+        MemorySizeInfo
+        ParserStateMachine::_store_info(std::size_t i) const noexcept
+        {
+            size_t n0 = stringtable_._n_store();
+
+            if (i < n0) 
+                return stringtable_._store_info(i);
+
+            if (i == n0)
+                return parser_alloc_._store_info();
+
+            // not counting expr_alloc_. We don't consider
+            // that to be owned by ParserStateMachine
+
+            return MemorySizeInfo::sentinel();
+        }
+
         void
         ParserStateMachine::establish_toplevel_ssm(obj<ASyntaxStateMachine> ssm)
         {
diff --git a/src/reader2/SchematikaParser.cpp b/src/reader2/SchematikaParser.cpp
index e584044c..07c74d17 100644
--- a/src/reader2/SchematikaParser.cpp
+++ b/src/reader2/SchematikaParser.cpp
@@ -13,6 +13,7 @@
 
 namespace xo {
     using xo::mm::AAllocator;
+    using xo::mm::MemorySizeInfo;
     using xo::tostr;
     using xo::xtag;
 
@@ -46,6 +47,18 @@ namespace xo {
             return psm_.top_ssm();
         }
 
+        std::size_t
+        SchematikaParser::_n_store() const noexcept
+        {
+            return psm_._n_store();
+        }
+
+        MemorySizeInfo
+        SchematikaParser::_store_info(std::size_t i) const noexcept
+        {
+            return psm_._store_info(i);
+        }
+
         void
         SchematikaParser::begin_interactive_session()
         {
diff --git a/src/reader2/SchematikaReader.cpp b/src/reader2/SchematikaReader.cpp
index 4dd8600c..097c68df 100644
--- a/src/reader2/SchematikaReader.cpp
+++ b/src/reader2/SchematikaReader.cpp
@@ -6,6 +6,8 @@
 #include "SchematikaReader.hpp"
 
 namespace xo {
+    using xo::mm::MemorySizeInfo;
+
     namespace scm {
         SchematikaReader::SchematikaReader(const ReaderConfig & config,
                                            obj<AAllocator> expr_alloc)
@@ -19,6 +21,29 @@ namespace xo {
         {
         }
 
+        std::size_t
+        SchematikaReader::_n_store() const noexcept
+        {
+            return tokenizer_._n_store() + parser_._n_store();
+        }
+        
+        MemorySizeInfo
+        SchematikaReader::_store_info(std::size_t i) const noexcept
+        {
+            size_t n_tk = tokenizer_._n_store();
+
+            if (i < n_tk) {
+                return tokenizer_._store_info(i);
+            }
+
+            size_t n_pr = parser_._n_store();
+
+            if (i < n_tk + n_pr)
+                return parser_._store_info(i - n_tk);
+
+            return MemorySizeInfo::sentinel();
+        }
+
         bool
         SchematikaReader::is_at_toplevel() const noexcept
         {
@@ -31,6 +56,12 @@ namespace xo {
             parser_.begin_interactive_session();
         }
 
+        void
+        SchematikaReader::begin_batch_session()
+        {
+            parser_.begin_batch_session();
+        }
+
         // TODO:
         // Schematika::end_interactive_session()