diff --git a/.gitignore b/.gitignore
index c368d45..3539501 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 .stack-work/
-*~
\ No newline at end of file
+*~
+database/*
\ No newline at end of file
diff --git a/app/Main.hs b/app/Main.hs
index d970085..c7441db 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -13,6 +13,7 @@ main :: IO ()
 main = do
   port <- determinePort
   putStrLn $ "Try: http://localhost:" ++ show port ++ "/auth?scope=ID%20Profile&client_id=42&response_type=code&redirect_uri=http:%2F%2Flocalhost:0000%2F"
+  initDB
   runMockServer @User @(M.Map T.Text T.Text) port
     where
       determinePort :: IO Int
diff --git a/flake.nix b/flake.nix
index 9d98e99..1f6a556 100644
--- a/flake.nix
+++ b/flake.nix
@@ -32,6 +32,7 @@
     devShells.${system}.default = pkgs.mkShell {
       buildInputs = buildInputs;
       LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath buildInputs;
+      shellHook = "./mkDB.sh";
     };
   };
 }
diff --git a/hba_file b/hba_file
new file mode 100644
index 0000000..a5e9c72
--- /dev/null
+++ b/hba_file
@@ -0,0 +1 @@
+local all all trust
\ No newline at end of file
diff --git a/mkDB.sh b/mkDB.sh
new file mode 100644
index 0000000..86c0988
--- /dev/null
+++ b/mkDB.sh
@@ -0,0 +1,28 @@
+#!/bin/sh -e
+
+export OAUTH2_SERVER_PORT=9443
+export OAUTH2_DB_PORT=9444
+
+tmpdir=./database
+
+if [ ! -d "${tmpdir}" ]; then
+  mkdir ${tmpdir}
+fi
+
+pgDir=$(mktemp -d --tmpdir="${tmpdir}" postgresql.XXXXXX)
+pgSockDir=$(mktemp -d --tmpdir="${tmpdir}" postgresql.sock.XXXXXX)
+pgLogFile=$(mktemp --tmpdir="${tmpdir}" postgresql.XXXXXX.log)
+
+initdb --no-locale -D "${pgDir}"
+pg_ctl start -D "${pgDir}" -l "${pgLogFile}" -w -o "-k ${pgSockDir} -c listen_addresses=''' -c hba_file='hba_file' -p ${OAUTH2_DB_PORT} -h localhost -c unix_socket_permissions=0700 -c max_connections=10 -c session_preload_libraries=auto_explain -c auto_explain.log_min_duration=100ms"
+psql -h "${pgSockDir}" -f ./schema.sql postgres
+
+printf "Postgres logfile is %s\nPostgres socket directory is %s\n" "${pgLogFile}" "${pgSockDir}"
+
+export PGHOST="${pgSockDir}"
+export PGLOG="${pgLogFile}"
+
+zsh
+
+pg_ctl stop -D "${pgDir}"
+rm -rvf "${pgDir}" "${pgSockDir}" "${pgLogFile}"
diff --git a/schema.sql b/schema.sql
new file mode 100644
index 0000000..623a741
--- /dev/null
+++ b/schema.sql
@@ -0,0 +1,3 @@
+CREATE USER oauth2mock WITH SUPERUSER;
+CREATE DATABASE test_users;
+GRANT ALL ON DATABASE test_users TO oauth2mock;