diff --git a/lib/imc_channel.hpp b/lib/imc_channel.hpp
index 6a7f34d..7379178 100644
--- a/lib/imc_channel.hpp
+++ b/lib/imc_channel.hpp
@@ -4,6 +4,7 @@
 #define IMCCHANNEL
 
 #include <sstream>
+#include "imc_datatype.hpp"
 
 //---------------------------------------------------------------------------//
 
@@ -59,25 +60,113 @@ namespace imc
         <<std::setw(width)<<std::left<<"NOuuid:"<<NOuuid_<<"\n";
       return ss.str();
     }
+
+    // get JSON info string
+    std::string get_json()
+    {
+      std::stringstream ss;
+      ss<<"{"<<"\"uuid\":\""<<uuid_
+             <<"\",\"CBuuid\":\""<<CBuuid_
+             <<"\",\"CGuuid\":\""<<CGuuid_
+             <<"\",\"CCuuid\":\""<<CCuuid_
+             <<"\",\"CNuuid\":\""<<CNuuid_
+             <<"\",\"CDuuid\":\""<<CDuuid_
+             <<"\",\"CTuuid\":\""<<CTuuid_
+             <<"\",\"Cbuuid\":\""<<Cbuuid_
+             <<"\",\"CPuuid\":\""<<CPuuid_
+             <<"\",\"CRuuid\":\""<<CRuuid_
+             <<"\",\"CSuuid\":\""<<CSuuid_
+             <<"\",\"NTuuid\":\""<<NTuuid_
+             <<"\",\"NOuuid\":\""<<NOuuid_
+             <<"\"}";
+      return ss.str();
+    }
   };
 
-  // actual result and (meta)data of channel
-  struct channel_data
+  // given a list of numeric objects, join it into a string
+  template<typename dt>
+  std::string joinvec(std::vector<dt> myvec, unsigned long int limit = 10)
   {
+    std::stringstream ss;
+    ss<<"[";
+    if ( myvec.size() <= limit )
+    {
+      for ( dt el: myvec ) ss<<el<<",";
+    }
+    else
+    {
+      unsigned long int heals = (unsigned long int)(limit/2.);
+      for ( unsigned long int i = 0; i < heals; i++ ) ss<<myvec[i]<<",";
+      ss<<"...";
+      for ( unsigned long int i = myvec.size()-heals; i < myvec.size(); i++ )
+      {
+        ss<<myvec[i]<<",";
+      }
+    }
+    std::string sumstr = ss.str();
+    if ( sumstr.size() > 1 ) sumstr.pop_back();
+    sumstr += std::string("]");
+    return sumstr;
+  }
+
+  // channel
+  struct channel
+  {
+    // associated environment of blocks and map of blocks
+    channel_env chnenv_;
+    const std::map<std::string,imc::block>* blocks_;
+
     // collect meta-data of channels according to env,
     //  just everything valueable in here
     std::string uuid_;
     std::string name_;
-    std::string yunit_;
-    std::string xunit_;
+    std::string yname_, yunit_;
+    imc::datatype dattyp_;
+    std::string xname_, xunit_;
     std::vector<imc::datatype> ydata_;
     std::vector<imc::datatype> xdata_;
 
-    // provide JSON sttring of metadata
+    // group reference the channel belongs to
+    std::string group_uuid_, group_name_;
+
+    // constructor takes channel's block environment
+    channel(channel_env chnenv, std::map<std::string,imc::block>* blocks):
+      chnenv_(chnenv), blocks_(blocks)
+    {
+      std::vector<imc::parameter> prms = blocks->at(chnenv_.CNuuid_).get_parameters();
+      name_ = blocks->at(chnenv_.CNuuid_).get_parameter(prms[6]);
+    }
+
+    // get info string
+    std::string get_info(int width = 20)
+    {
+      std::stringstream ss;
+      ss<<"uuid:"<<std::setw(width)<<std::left<<uuid_<<"\n"
+        <<"name:"<<std::setw(width)<<std::left<<name_<<"\n"
+        <<"yname:"<<std::setw(width)<<std::left<<yname_<<"\n"
+        <<"yunit:"<<std::setw(width)<<std::left<<yunit_<<"\n"
+        <<"xname:"<<std::setw(width)<<std::left<<xname_<<"\n"
+        <<"xunit:"<<std::setw(width)<<std::left<<xunit_<<"\n"
+        <<"group:"<<std::setw(width)<<std::left<<group_name_<<"\n"
+        <<"aff. blocks:"<<std::setw(width)<<std::left<<chnenv_.get_json()<<"\n";
+      return ss.str();
+    }
+
+    // provide JSON string of metadata
     std::string get_json()
     {
       std::stringstream ss;
-      ss<<""<<"\n";
+      ss<<"{"<<"\"uuid\":\""<<uuid_
+             <<"\",\"name\":\""<<name_
+             <<"\",\"yname\":\""<<yname_
+             <<"\",\"yunit\":\""<<yunit_
+             <<"\",\"xname\":\""<<xname_
+             <<"\",\"xunit\":\""<<xunit_
+             <<"\",\"group\":\""<<group_name_
+             <<"\",\"ydata\":\""<<imc::joinvec<imc::datatype>(ydata_)
+             <<"\",\"xdata\":\""<<imc::joinvec<imc::datatype>(xdata_)
+             <<"\",\"aff. blocks\":\""<<chnenv_.get_json()
+             <<"\"}";
       return ss.str();
     }
 
diff --git a/lib/imc_object.hpp b/lib/imc_object.hpp
index 17f4e66..e7a833d 100644
--- a/lib/imc_object.hpp
+++ b/lib/imc_object.hpp
@@ -75,7 +75,7 @@ namespace imc
   };
 
   // group definition (corresponds to key CB)
-  struct group
+  struct groupobj
   {
     unsigned long int group_index_;
     std::string name_;
@@ -400,7 +400,7 @@ namespace imc
   };
 
   // channel (corresponds to key CN)
-  struct channel
+  struct channelobj
   {
     unsigned long int group_index_;  // corresponds to group-index in CB key
     bool index_bit_;                 // true =  1: digital, false = 0: analog
@@ -538,7 +538,7 @@ namespace imc {
   {
     format fmt_;      // 0
     keygroup kyg_;    // 1
-    group grp_;       // 2
+    groupobj grp_;       // 2
     text txt_;        // 3
     datafield dtf_;   // 4
     abscissa abs_;    // 5
@@ -546,7 +546,7 @@ namespace imc {
     packaging pkg_;   // 7
     buffer bfr_;      // 8
     range rng_;       // 9
-    channel chn_;     // 10
+    channelobj chn_;     // 10
     data dat_;        // 11
     origin_data org_; // 12
     triggertime trt_; // 13
diff --git a/lib/imc_raw.hpp b/lib/imc_raw.hpp
index 7a073a6..cdef55f 100644
--- a/lib/imc_raw.hpp
+++ b/lib/imc_raw.hpp
@@ -33,8 +33,8 @@ namespace imc
     // check computational complexity for parsing blocks
     unsigned long int cplxcnt_;
 
-    // list groups and channels with their affiliate blocks
-    std::map<std::string,imc::channel_env> channel_envs_;
+    // list groups and channels (including their affiliate blocks)
+    std::map<std::string,imc::channel> channels_;
 
   public:
 
@@ -224,11 +224,13 @@ namespace imc
           if ( blk.get_key().name_ == "CS" || blk.get_key().name_ == "CC"
             || blk.get_key().name_ == "CG" || blk.get_key().name_ == "CB" )
           {
+            // provide UUID for channel
             chnenv.uuid_ = chnenv.CNuuid_;
-            channel_envs_.insert(
-              std::pair<std::string,imc::channel_env>(chnenv.CNuuid_,chnenv)
+
+            // create channel object and add it to the map of channels
+            channels_.insert( std::pair<std::string,imc::channel>
+              (chnenv.CNuuid_,imc::channel(chnenv,&mapblocks_))
             );
-            std::cout<<chnenv.get_info()<<"\n";
 
             // reset channel uuid
             chnenv.CNuuid_.clear();
@@ -293,6 +295,31 @@ namespace imc
       return cplxcnt_;
     }
 
+    // get list of channels with metadata
+    std::vector<std::string> get_channels()
+    {
+      std::vector<std::string> chns;
+      for ( std::map<std::string,imc::channel>::iterator it = channels_.begin();
+                                                         it != channels_.end(); ++it)
+      {
+        chns.push_back(it->second.get_json());
+      }
+      return chns;
+    }
+
+    // get particular channel including data by its uuid
+    imc::channel get_channel(std::string uuid)
+    {
+      if ( channels_.count(uuid) )
+      {
+        return channels_.at(uuid);
+      }
+      else
+      {
+        throw std::runtime_error(std::string("channel does not exist:") + uuid);
+      }
+    }
+
     // list a particular type of block
     std::vector<imc::block> list_blocks(imc::key mykey)
     {
diff --git a/src/main.cpp b/src/main.cpp
index 10957e8..9f30ac2 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -180,26 +180,11 @@ int main(int argc, char* argv[])
     std::cout<<"computational complexity: "<<imcraw.computational_complexity()
                                            <<"/"<<imcraw.buffer_size()<<"\n\n";
 
-    // list specific blocks
-    // std::vector<imc::block> CBblocks = imcraw.list_blocks(imc::keys.at("CB"));
-    // for ( auto blk: CBblocks ) std::cout<<blk.get_info()<<"\n";
-    // std::vector<imc::block> CGblocks = imcraw.list_blocks(imc::keys.at("CG"));
-    // for ( auto blk: CGblocks ) std::cout<<blk.get_info()<<"\n";
-    // std::vector<imc::block> CCblocks = imcraw.list_blocks(imc::keys.at("CC"));
-    // for ( auto blk: CCblocks ) std::cout<<blk.get_info()<<"\n";
-    // std::vector<imc::block> CNblocks = imcraw.list_blocks(imc::keys.at("CN"));
-    // for ( auto blk: CNblocks ) std::cout<<blk.get_info()<<"\n";
-    // std::vector<imc::block> CSblocks = imcraw.list_blocks(imc::keys.at("CS"));
-    // for ( auto blk: CSblocks ) std::cout<<blk.get_info()<<"\n";
-    // std::vector<imc::block> groups = imcraw.list_groups();
-    // for ( auto blk: groups ) std::cout<<blk.get_info()<<"\n";
+    // list channels
+    std::cout<<"list of channels:\n";
+    std::vector<std::string> channels = imcraw.get_channels();
+    for ( auto el: channels ) std::cout<<el<<"\n";
 
-    // std::vector<std::string> channels = imcraw.list_channels();
-    // for ( auto chn: channels )
-    // {
-    //   std::cout<<chn<<"\n";
-    //   imc::channel_tab chtab = imcraw.get_channel(chn);
-    // }
   }
 
   return 0;