diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,5 +1,95 @@
-Copyright 2016 - Helium Systems, Inc.
 Copyright 2017 - Jonathan Fischoff
+
+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 the copyright holder nor the
+      names of its 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 HOLDER 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.
+
+Copyright (c) 2011, Leon P Smith
+
+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 Leon P Smith 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.
+
+
+Copyright (c) 2011, MailRank, Inc.
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+
+2. 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.
+
+3. Neither the name of the author nor the names of his contributors
+   may be used to endorse or promote products derived from this software
+   without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE 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 AUTHORS 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.
+
+Copyright 2016 - Helium Systems, Inc.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:
diff --git a/pg-transact.cabal b/pg-transact.cabal
--- a/pg-transact.cabal
+++ b/pg-transact.cabal
@@ -1,5 +1,5 @@
 name:                pg-transact
-version:             0.1.0.0
+version:             0.1.0.1
 synopsis: Another postgresql-simple transaction monad
 description: Another postgresql-simple transaction monad
 homepage:            https://github.com/jfischoff/pg-transact#readme
diff --git a/src/Database/PostgreSQL/Transact.hs b/src/Database/PostgreSQL/Transact.hs
--- a/src/Database/PostgreSQL/Transact.hs
+++ b/src/Database/PostgreSQL/Transact.hs
@@ -60,20 +60,89 @@
   $ run
   $ runReaderT (unDBT action) conn
 
+-- | Perform a @SELECT@ or other SQL query that is expected to return
+-- results. All results are retrieved and converted before this
+-- function returns.
+--
+-- When processing large results, this function will consume a lot of
+-- client-side memory.  Consider using 'fold' instead.
+--
+-- Exceptions that may be thrown:
+--
+-- * 'FormatError': the query string could not be formatted correctly.
+--
+-- * 'QueryError': the result contains no columns (i.e. you should be
+--   using 'execute' instead of 'query').
+--
+-- * 'ResultError': result conversion failed.
+--
+-- * 'SqlError':  the postgresql backend returned an error,  e.g.
+--   a syntax or type error,  or an incorrect table or column name.
 query :: (ToRow a, FromRow b, MonadIO m) => Query -> a -> DBT m [b]
 query q x = getConnection >>= \conn -> liftIO $ Simple.query conn q x
 
+-- | A version of 'query' that does not perform query substitution.
 query_ :: (FromRow b, MonadIO m) => Query -> DBT m [b]
 query_ q = getConnection >>= \conn -> liftIO $ Simple.query_ conn q
 
+-- | Execute an @INSERT@, @UPDATE@, or other SQL query that is not
+-- expected to return results.
+--
+-- Returns the number of rows affected.
+--
+-- Throws 'FormatError' if the query could not be formatted correctly, or
+-- a 'SqlError' exception if the backend returns an error.
 execute :: (ToRow q, MonadIO m) => Query -> q -> DBT m Int64
 execute q x = getConnection >>= \conn -> liftIO $ Simple.execute conn q x
 
+-- | A version of execute that does not perform query substitution.
 execute_ :: MonadIO m => Query -> DBT m Int64
 execute_ q = getConnection >>= \conn -> liftIO $ Simple.execute_ conn q
 
+-- | Execute a multi-row @INSERT@, @UPDATE@, or other SQL query that is not
+-- expected to return results.
+--
+-- Returns the number of rows affected.   If the list of parameters is empty,
+-- this function will simply return 0 without issuing the query to the backend.
+-- If this is not desired, consider using the 'Values' constructor instead.
+--
+-- Throws 'FormatError' if the query could not be formatted correctly, or
+-- a 'SqlError' exception if the backend returns an error.
+--
+-- For example,  here's a command that inserts two rows into a table
+-- with two columns:
+--
+-- @
+-- executeMany [sql|
+--     INSERT INTO sometable VALUES (?,?)
+--  |] [(1, \"hello\"),(2, \"world\")]
+-- @
+--
+-- Here's an canonical example of a multi-row update command:
+--
+-- @
+-- executeMany [sql|
+--     UPDATE sometable
+--        SET sometable.y = upd.y
+--       FROM (VALUES (?,?)) as upd(x,y)
+--      WHERE sometable.x = upd.x
+--  |] [(1, \"hello\"),(2, \"world\")]
+-- @
+
 executeMany :: (ToRow q, MonadIO m) => Query -> [q] -> DBT m Int64
 executeMany q xs = getConnection >>= \conn -> liftIO $ Simple.executeMany conn q xs
 
+-- | Execute @INSERT ... RETURNING@, @UPDATE ... RETURNING@, or other SQL
+-- query that accepts multi-row input and is expected to return results.
+-- Note that it is possible to write
+--    @'query' conn "INSERT ... RETURNING ..." ...@
+-- in cases where you are only inserting a single row,  and do not need
+-- functionality analogous to 'executeMany'.
+--
+-- If the list of parameters is empty,  this function will simply return @[]@
+-- without issuing the query to the backend.   If this is not desired,
+-- consider using the 'Values' constructor instead.
+--
+-- Throws 'FormatError' if the query could not be formatted correctly.
 returning :: (ToRow q, FromRow r, MonadIO m) => Query -> [q] -> DBT m [r]
 returning q xs = getConnection >>= \conn -> liftIO $ Simple.returning conn q xs