diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Revision history for dep-t
 
+
+## 0.6.6
+
+* Added Dep.Phases. 
+
+* Added Dep.Injects.
+
 ## 0.6.5
 
 * Deprecated `Constructor`, `fixEnv` and the `Accum-` counterparts from `Dep.Env`.
diff --git a/dep-t.cabal b/dep-t.cabal
--- a/dep-t.cabal
+++ b/dep-t.cabal
@@ -1,7 +1,7 @@
 cabal-version:       3.0
 
 name:                dep-t
-version:             0.6.5.0
+version:             0.6.6.0
 synopsis:            Dependency injection for records-of-functions.
 description:         Put all your functions in the environment record! Let all
                      your functions read from the environment record! No favorites!
@@ -27,9 +27,11 @@
 library
   import: common
   exposed-modules:     Dep.Has
+                       Dep.Injects
                        Dep.Env
                        Dep.Constructor
                        Dep.Tagged
+                       Dep.Phases
                        Control.Monad.Dep
                        Control.Monad.Dep.Class
   hs-source-dirs:      lib 
diff --git a/lib/Dep/Has.hs b/lib/Dep/Has.hs
--- a/lib/Dep/Has.hs
+++ b/lib/Dep/Has.hs
@@ -103,7 +103,7 @@
 -- The constraint can be used on its own, or with "Control.Monad.Dep.Class".
 type Has :: ((Type -> Type) -> Type) -> (Type -> Type) -> Type -> Constraint
 class Has r_ (m :: Type -> Type) (env :: Type) | env -> m where
-  -- |  Given an environment @e@, produce a record-of-functions parameterized by the environment's effect monad @m@.
+  -- |  Given an environment @env@, produce a record-of-functions parameterized by the environment's effect monad @m@.
   --
   -- The hope is that using a selector function on the resulting record will
   -- fix the record's type without the need for type annotations.
diff --git a/lib/Dep/Injects.hs b/lib/Dep/Injects.hs
new file mode 100644
--- /dev/null
+++ b/lib/Dep/Injects.hs
@@ -0,0 +1,43 @@
+{-# LANGUAGE AllowAmbiguousTypes #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE DefaultSignatures #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FunctionalDependencies #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE PolyKinds #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE StandaloneKindSignatures #-}
+{-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE ViewPatterns #-}
+{-# LANGUAGE ImportQualifiedPost #-}
+{-# LANGUAGE TypeOperators #-}
+
+-- | Inject values into accumulators.
+module Dep.Injects (
+    -- * General-purpose injector.
+    Injects (..)
+    ) where
+
+import Data.Kind
+import GHC.Records
+import GHC.TypeLits
+import Data.Coerce
+
+-- | Mirror image of 'Dep.Has.Has'.
+--
+-- Can be useful with 'Dep.Constructor.AccumConstructor' to register particular
+-- monoidal values into a \"wider"\ monoidal value which is accumulated accross
+-- all components.
+type Injects :: ((Type -> Type) -> Type) -> (Type -> Type) -> Type -> Constraint
+class Injects r_ (m :: Type -> Type) (accum :: Type) | accum -> m where
+    -- | Given a value parameterized by the accumulator's effect monad @m@,
+    -- produce an accumulator.
+    inject :: r_ m -> accum
+
+
+
+
diff --git a/lib/Dep/Phases.hs b/lib/Dep/Phases.hs
new file mode 100644
--- /dev/null
+++ b/lib/Dep/Phases.hs
@@ -0,0 +1,102 @@
+module Dep.Phases (
+    -- * Qualified do-notation for building phases
+    -- $warning
+    (>>=), 
+    (>>),
+    -- * Re-exports
+    Compose (..),
+    ) where
+
+import Data.Functor.Compose
+import Prelude (Functor, (<$>), (<$))
+
+(>>=) :: Functor f => f x -> (x -> g y) -> Compose f g y
+f >>= k = Compose (k <$> f)
+
+(>>) :: Functor f => f x -> g y -> Compose f g y
+f >> g = Compose (g <$ f)
+
+-- $warning
+-- Convenient [qualified
+-- do-notation](https://downloads.haskell.org/ghc/latest/docs/users_guide/exts/qualified_do.html#extension-QualifiedDo)
+-- for defining nested applicative phases wrapped in 'Compose's.
+-- 
+-- __BEWARE__! Despite its convenience, this do-notation lacks [many of the properties](https://wiki.haskell.org/Monad_laws#The_monad_laws_in_practice) 
+-- we tend to assume when working with do-notation. In particular, it's 
+-- NOT associative! This means that if we have 
+--
+-- @
+-- Dep.Phases.do    
+--    somePhase
+--    someOtherPhase
+--    finalPhase
+-- @
+--
+-- we CAN'T refactor to
+--
+-- @
+-- Dep.Phases.do    
+--    Dep.Phases.do 
+--      somePhase
+--      someOtherPhase
+--    finalPhase
+-- @
+--
+-- It would indeed be useful (it would allow pre-packaging and sharing initial
+-- phases as do-blocks) but it isn't supported.
+--
+-- __BEWARE__ #2! Do not use 'return' in this do-notation.
+--
+-- Some valid examples:
+--
+-- >>> :{
+-- type Phases = (IO `Compose` IO `Compose` IO) Int
+-- phases :: Phases
+-- phases = Dep.Phases.do
+--    r1 <- pure 1
+--    r2 <- pure 2
+--    pure $ r1 + r2
+-- :}
+--
+--
+-- >>> :{
+-- type Phases = (IO `Compose` Maybe `Compose` Either Char) Int
+-- phases :: Phases
+-- phases = Dep.Phases.do
+--    pure ()
+--    Just 5
+--    Left 'e'
+-- :}
+--
+--
+
+
+-- $setup
+--
+-- >>> :set -XTypeApplications
+-- >>> :set -XMultiParamTypeClasses
+-- >>> :set -XImportQualifiedPost
+-- >>> :set -XStandaloneKindSignatures
+-- >>> :set -XNamedFieldPuns
+-- >>> :set -XFunctionalDependencies
+-- >>> :set -XFlexibleContexts
+-- >>> :set -XDataKinds
+-- >>> :set -XBlockArguments
+-- >>> :set -XFlexibleInstances
+-- >>> :set -XTypeFamilies
+-- >>> :set -XDeriveGeneric
+-- >>> :set -XViewPatterns
+-- >>> :set -XDerivingStrategies
+-- >>> :set -XDerivingVia
+-- >>> :set -XDeriveAnyClass
+-- >>> :set -XStandaloneDeriving
+-- >>> :set -XUndecidableInstances
+-- >>> :set -XTypeOperators
+-- >>> :set -XScopedTypeVariables
+-- >>> :set -XQualifiedDo
+-- >>> :set -fno-warn-deprecations
+-- >>> import Data.Kind
+-- >>> import Data.Function ((&))
+-- >>> import Dep.Env
+-- >>> import GHC.Generics (Generic)
+-- >>> import Prelude hiding ((>>=), (>>))
diff --git a/test/doctests.hs b/test/doctests.hs
--- a/test/doctests.hs
+++ b/test/doctests.hs
@@ -6,7 +6,9 @@
     "lib/Control/Monad/Dep.hs", 
     "lib/Control/Monad/Dep/Class.hs", 
     "lib/Dep/Has.hs", 
+    "lib/Dep/Injects.hs", 
     "lib/Dep/Env.hs",
+    "lib/Dep/Phases.hs", 
     "lib/Dep/Constructor.hs",
     "lib/Dep/Tagged.hs"
     ]