diff --git a/ChangeLog.md b/ChangeLog.md
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+++ b/ChangeLog.md
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+# Changelog for polysemy-methodology-co-log
+
+## v0.1.0.0
+
+Add `logMethodologyStart`, `logMethodologyEnd` and `logMethodologyAround`.
diff --git a/LICENSE b/LICENSE
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--- /dev/null
+++ b/LICENSE
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+Copyright Daniel Firth (c) 2020
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Author name here nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/README.md b/README.md
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+++ b/README.md
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+# polysemy-methodology-co-log
+
+Logging for [polysemy-methodology](https://hackage.haskell.org/package/polysemy-methodology).
diff --git a/polysemy-methodology-co-log.cabal b/polysemy-methodology-co-log.cabal
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+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.34.4.
+--
+-- see: https://github.com/sol/hpack
+
+name:           polysemy-methodology-co-log
+version:        0.1.0.0
+synopsis:       Logging functions for polysemy-methodology.
+category:       Polysemy
+author:         Daniel Firth
+maintainer:     dan.firth@homotopic.tech
+copyright:      2020 Daniel Firth
+license:        MIT
+license-file:   LICENSE
+build-type:     Simple
+extra-source-files:
+    README.md
+    ChangeLog.md
+
+source-repository head
+  type: git
+  location: https://gitlab.com/homotopic-tech/polysemy-methodology-co-log
+
+library
+  exposed-modules:
+      Polysemy.Methodology.Colog
+  other-modules:
+      Paths_polysemy_methodology_co_log
+  hs-source-dirs:
+      src
+  ghc-options: -Wall -Wcompat -Wincomplete-record-updates -Wincomplete-uni-patterns -Wredundant-constraints
+  build-depends:
+      base >=4.7 && <4.16
+    , co-log-polysemy
+    , polysemy >=1.3.0.0 && <1.7
+    , polysemy-methodology >=0.1 && <0.3
+    , polysemy-plugin >=0.3 && <0.5
+  default-language: Haskell2010
diff --git a/src/Polysemy/Methodology/Colog.hs b/src/Polysemy/Methodology/Colog.hs
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+++ b/src/Polysemy/Methodology/Colog.hs
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+{-# LANGUAGE AllowAmbiguousTypes #-}
+{-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE GADTs #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE PolyKinds #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE TypeOperators #-}
+{-# OPTIONS_GHC -fplugin=Polysemy.Plugin #-}
+
+-- |
+--   Module     : Polysemy.Methodology
+--   License    : MIT
+--   Stability  : experimental
+--
+-- Domain modelling algebra for polysemy.
+module Polysemy.Methodology.Colog
+  ( -- * Logging
+    logMethodologyStart,
+    logMethodologyEnd,
+    logMethodologyAround,
+  )
+where
+
+import Colog.Polysemy as C
+import Polysemy
+import Polysemy.Methodology
+
+-- | `Log` a type based on the input to a `Methodology`.
+--
+-- @since 0.1.0.0
+logMethodologyStart ::
+  forall b c p r a.
+  Members
+    '[ Methodology b c,
+       Log p
+     ]
+    r =>
+  -- | A function from the input type b to an event type p.
+  (b -> p) ->
+  Sem r a ->
+  Sem r a
+logMethodologyStart f = intercept \case
+  Process b -> C.log (f b) >> process @b @c b
+{-# INLINE logMethodologyStart #-}
+
+-- | `Log` a type based on the output to a `Methodology`.
+--
+-- @since 0.1.0.0
+logMethodologyEnd ::
+  forall b c q r a.
+  Members
+    '[ Methodology b c,
+       Log q
+     ]
+    r =>
+  -- | A function from the input type c to an event type q.
+  (c -> q) ->
+  Sem r a ->
+  Sem r a
+logMethodologyEnd f = intercept \case
+  Process b -> do
+    c <- process @b @c b
+    C.log $ f c
+    return c
+{-# INLINE logMethodologyEnd #-}
+
+-- | `Log` both the start and the end of a `Methodology`.
+--
+-- @since 0.1.0.0
+logMethodologyAround ::
+  forall b c p q r a.
+  Members
+    '[ Methodology b c,
+       Log p,
+       Log q
+     ]
+    r =>
+  -- | A function from the input type b to an event type p.
+  (b -> p) ->
+  -- | A function from the output type b to an event type q,
+  (c -> q) ->
+  Sem r a ->
+  Sem r a
+logMethodologyAround f g = intercept \case
+  Process b -> do
+    C.log $ f b
+    c <- process @b @c b
+    C.log $ g c
+    return c
+{-# INLINE logMethodologyAround #-}