diff --git a/src/telem/init.lua b/src/telem/init.lua
index 0e9ed77..411fa4f 100644
--- a/src/telem/init.lua
+++ b/src/telem/init.lua
@@ -1,9 +1,13 @@
 local _Telem = {
-    _VERSION = '0.0.3',
+    _VERSION = '0.1.0',
     util = require 'telem.lib.util',
     input = require 'telem.lib.input',
     output = require 'telem.lib.output',
-    backplane = require 'telem.lib.Backplane'
+    
+    -- API
+    backplane = require 'telem.lib.Backplane',
+    metric = require 'telem.lib.Metric',
+    metricCollection = require 'telem.lib.MetricCollection'
 }
 
 -- _Telem.util.log('init')
diff --git a/src/telem/lib/Metric.lua b/src/telem/lib/Metric.lua
index c3425aa..42dbd51 100644
--- a/src/telem/lib/Metric.lua
+++ b/src/telem/lib/Metric.lua
@@ -13,6 +13,8 @@ function Metric:constructor (data, data2)
         datum = { name = data, value = data2 }
     end
 
+    assert(type(datum.value) == 'number', 'Metric value must be a number')
+
     self.name = assert(datum.name, 'Metric must have a name')
     self.value = assert(datum.value, 'Metric must have a value')
     self.unit = datum.unit or nil
diff --git a/src/telem/lib/input.lua b/src/telem/lib/input.lua
index b80329c..f369ea8 100644
--- a/src/telem/lib/input.lua
+++ b/src/telem/lib/input.lua
@@ -1,5 +1,6 @@
 return {
     helloWorld = require 'telem.lib.input.HelloWorldInputAdapter',
+    custom = require 'telem.lib.input.CustomInputAdapter',
 
     -- storage
     itemStorage = require 'telem.lib.input.ItemStorageInputAdapter',
diff --git a/src/telem/lib/input/CustomInputAdapter.lua b/src/telem/lib/input/CustomInputAdapter.lua
new file mode 100644
index 0000000..4290feb
--- /dev/null
+++ b/src/telem/lib/input/CustomInputAdapter.lua
@@ -0,0 +1,21 @@
+local o = require 'telem.lib.ObjectModel'
+local t = require 'telem.lib.util'
+
+local InputAdapter      = require 'telem.lib.InputAdapter'
+local Metric            = require 'telem.lib.Metric'
+local MetricCollection  = require 'telem.lib.MetricCollection'
+
+local CustomInputAdapter = o.class(InputAdapter)
+CustomInputAdapter.type = 'CustomInputAdapter'
+
+function CustomInputAdapter:constructor (func)
+    self.readlambda = func
+
+    self:super('constructor')
+end
+
+function CustomInputAdapter:read ()
+    return MetricCollection(self.readlambda())
+end
+
+return CustomInputAdapter
\ No newline at end of file
diff --git a/src/telem/lib/output.lua b/src/telem/lib/output.lua
index 6203f11..291a755 100644
--- a/src/telem/lib/output.lua
+++ b/src/telem/lib/output.lua
@@ -1,5 +1,6 @@
 return {
     helloWorld = require 'telem.lib.output.HelloWorldOutputAdapter',
+    custom = require 'telem.lib.output.CustomOutputAdapter',
 
     -- HTTP
     grafana = require 'telem.lib.output.GrafanaOutputAdapter',
diff --git a/src/telem/lib/output/CustomOutputAdapter.lua b/src/telem/lib/output/CustomOutputAdapter.lua
new file mode 100644
index 0000000..e176fca
--- /dev/null
+++ b/src/telem/lib/output/CustomOutputAdapter.lua
@@ -0,0 +1,22 @@
+local o = require 'telem.lib.ObjectModel'
+local t = require 'telem.lib.util'
+
+local OutputAdapter     = require 'telem.lib.OutputAdapter'
+local MetricCollection  = require 'telem.lib.MetricCollection'
+
+local CustomOutputAdapter = o.class(OutputAdapter)
+CustomOutputAdapter.type = 'CustomOutputAdapter'
+
+function CustomOutputAdapter:constructor (func)
+    self.writelambda = func
+
+    self:super('constructor')
+end
+
+function CustomOutputAdapter:write (collection)
+    assert(o.instanceof(collection, MetricCollection), 'Collection must be a MetricCollection')
+
+    self.writelambda(collection.metrics, collection.context)
+end
+
+return CustomOutputAdapter
\ No newline at end of file