diff --git a/antd-lua/antd-scm-1.rockspec b/antd-lua/antd-scm-1.rockspec
index a80ca95..3ab72c5 100644
--- a/antd-lua/antd-scm-1.rockspec
+++ b/antd-lua/antd-scm-1.rockspec
@@ -27,5 +27,6 @@ build = {
         ["antd.models"]   = "src/antd/models.lua",
         ["antd.errors"]   = "src/antd/errors.lua",
         ["antd.base64"]   = "src/antd/base64.lua",
+        ["antd.discover"] = "src/antd/discover.lua",
     },
 }
diff --git a/antd-lua/examples/02-data.lua b/antd-lua/examples/02-data.lua
index d97fd66..9e5212e 100644
--- a/antd-lua/examples/02-data.lua
+++ b/antd-lua/examples/02-data.lua
@@ -1,34 +1,40 @@
---- Example: Store and retrieve public data.
+--- Example 02: Store and retrieve public data, with cost estimation.
+--
+-- Prerequisite: antd daemon running on local testnet.
 
 local antd = require("antd")
 
 local client = antd.new_client()
 
--- Store public data
-local data = "Hello, Autonomi!"
-local result, err = client:data_put_public(data)
-if err then
-    print("Put error: " .. err.message)
+local payload = "Hello, Autonomi!"
+
+-- Estimate cost before storing
+local est, err1 = client:data_cost(payload)
+if err1 then
+    print("Cost error: " .. err1.message)
     os.exit(1)
 end
+print(string.format(
+    "Estimate: %d bytes in %d chunks, storage %s atto, gas %s wei, mode %s",
+    est.file_size, est.chunk_count, est.cost, est.estimated_gas_cost_wei, est.payment_mode
+))
 
-print("Stored at: " .. result.address)
-print("Cost: " .. result.cost .. " atto")
-
--- Retrieve it back
-local retrieved, err2 = client:data_get_public(result.address)
+-- Store public data
+local result, err2 = client:data_put_public(payload)
 if err2 then
-    print("Get error: " .. err2.message)
+    print("Put error: " .. err2.message)
     os.exit(1)
 end
+print("Stored at address: " .. result.address)
+print("Actual cost: " .. result.cost .. " atto tokens")
 
-print("Retrieved: " .. retrieved)
-
--- Estimate cost before storing
-local cost, err3 = client:data_cost("Some data to estimate")
+-- Retrieve it back
+local retrieved, err3 = client:data_get_public(result.address)
 if err3 then
-    print("Cost error: " .. err3.message)
+    print("Get error: " .. err3.message)
     os.exit(1)
 end
+print("Retrieved: " .. retrieved)
 
-print("Estimated cost: " .. cost .. " atto")
+assert(retrieved == payload, "Round-trip mismatch!")
+print("Public data round-trip OK!")
diff --git a/antd-lua/examples/04-files.lua b/antd-lua/examples/04-files.lua
index 7e7e01f..8f3908d 100644
--- a/antd-lua/examples/04-files.lua
+++ b/antd-lua/examples/04-files.lua
@@ -40,4 +40,4 @@ if err5 then
     os.exit(1)
 end
 
-print("Estimated upload cost: " .. cost .. " atto")
+print(string.format("Estimated upload cost: %s atto (%d chunks)", cost.cost, cost.chunk_count))
diff --git a/antd-lua/examples/05-graph.lua b/antd-lua/examples/05-graph.lua
index 8f1dbd5..210e371 100644
--- a/antd-lua/examples/05-graph.lua
+++ b/antd-lua/examples/05-graph.lua
@@ -47,4 +47,4 @@ if err4 then
     os.exit(1)
 end
 
-print("Estimated cost: " .. cost .. " atto")
+print(string.format("Estimated cost: %s atto (%d chunks)", cost.cost, cost.chunk_count))