diff --git a/cli/src/cmd/shared.rs b/cli/src/cmd/shared.rs
index 6ae2ff4a3..474bca280 100644
--- a/cli/src/cmd/shared.rs
+++ b/cli/src/cmd/shared.rs
@@ -1,6 +1,7 @@
 use clap::Arg;
 use failure::{format_err, Fallible};
-use std::path::Path;
+use std::env;
+use std::ffi::OsString;
 use taskchampion::{server, taskstorage, Replica, Task, Uuid};
 
 pub(super) fn task_arg<'a>() -> Arg<'a, 'a> {
@@ -46,14 +47,18 @@ impl CommandInvocation {
     // -- utilities for command invocations
 
     pub(super) fn get_replica(&self) -> Replica {
-        Replica::new(Box::new(
-            taskstorage::KVStorage::new(Path::new("/tmp/tasks")).unwrap(),
-        ))
+        // temporarily use $TASK_DB to locate the taskdb
+        let taskdb_dir = env::var_os("TASK_DB").unwrap_or_else(|| OsString::from("/tmp/tasks"));
+        Replica::new(Box::new(taskstorage::KVStorage::new(taskdb_dir).unwrap()))
     }
 
     pub(super) fn get_server(&self) -> Fallible<impl server::Server> {
+        // temporarily use $SYNC_SERVER_ORIGIN for the sync server
+        let sync_server_origin = env::var_os("SYNC_SERVER_ORIGIN")
+            .map(|osstr| osstr.into_string().unwrap())
+            .unwrap_or_else(|| String::from("http://localhost:8080"));
         Ok(server::RemoteServer::new(
-            "http://localhost:8080".into(),
+            sync_server_origin,
             Uuid::parse_str("d5b55cbd-9a82-4860-9a39-41b67893b22f").unwrap(),
         ))
     }
diff --git a/docs/src/usage.md b/docs/src/usage.md
index e284815bd..b16c724e1 100644
--- a/docs/src/usage.md
+++ b/docs/src/usage.md
@@ -1,6 +1,20 @@
 # Usage
 
+## `task`
+
 The main interface to your tasks is the `task` command, which supports various subcommands.
 You can find a quick list of all subcommands with `task help`.
 
 Note that the `task` interface does not match that of TaskWarrior.
+
+### Configuration
+
+Temporarily, configuration is by environment variables.
+The directory containing the replica's task data is given by `TASK_DB`, defaulting to `/tmp/tasks`.
+the origin of the sync server is given by `SYNC_SERVER_ORIGIN`, defaulting to `http://localhost:8080`.
+
+## `taskchampion-sync-server`
+
+Run `taskchampion-sync-server` to start the sync server.
+It serves on port 8080 on all interfaces, using an in-memory database (meaning that all data is lost when the process exits).
+Requests for previously-unknown clients are automatically added.
diff --git a/taskchampion/src/taskstorage/kv.rs b/taskchampion/src/taskstorage/kv.rs
index 87d8416c3..5e1cfde41 100644
--- a/taskchampion/src/taskstorage/kv.rs
+++ b/taskchampion/src/taskstorage/kv.rs
@@ -23,7 +23,7 @@ const NEXT_OPERATION: u64 = 2;
 const NEXT_WORKING_SET_INDEX: u64 = 3;
 
 impl<'t> KVStorage<'t> {
-    pub fn new(directory: &Path) -> Fallible<KVStorage> {
+    pub fn new<P: AsRef<Path>>(directory: P) -> Fallible<KVStorage<'t>> {
         let mut config = Config::default(directory);
         config.bucket("tasks", None);
         config.bucket("numbers", None);