diff --git a/src/proposer.js b/src/proposer.js
new file mode 100644
index 0000000..5634d87
--- /dev/null
+++ b/src/proposer.js
@@ -0,0 +1,82 @@
+// @ts-check
+
+import { nodeFetch } from './curl';
+import { RNode } from './rnode';
+
+const { freeze } = Object;
+
+/**
+ * @param {{ admin?: string, boot: string, read: string }} api
+ * @param {ReturnType<import('./rnode').RNode>} rnode
+ * @param {SchedulerAccess} sched
+ * @param {number=} period
+ *
+ * @typedef { {
+ *   setInterval: typeof setInterval,
+ *   clearInterval: typeof clearInterval,
+ * } } SchedulerAccess
+ */
+
+export function proposer(api, rnode, sched, period = 2 * 1000) {
+  let proposing = false;
+  let waiters = 0;
+  let pid;
+
+  return freeze({
+    startProposing() {
+      if (!api.admin) return;
+      const node = rnode.admin(api.admin);
+      waiters += 1;
+      if (typeof pid !== 'undefined') {
+        return;
+      }
+      pid = sched.setInterval(() => {
+        if (!proposing) {
+          proposing = true;
+          node
+            .propose()
+            .then(() => {
+              console.log('proposed', { waiters });
+              proposing = false;
+            })
+            .catch((err) => {
+              console.log('propose failed', { waiters, err: err.message });
+              proposing = false;
+            });
+        }
+      }, period);
+    },
+    stopProposing() {
+      if (waiters <= 0) {
+        return;
+      }
+      waiters -= 1;
+      sched.clearInterval(pid);
+      pid = undefined;
+    },
+  });
+}
+
+/**
+ * @param {string[]} args
+ * @param {{ http: typeof import('http') }} io
+ * @param {SchedulerAccess} sched
+ */
+function main(args, { http }, sched) {
+  const [url] = args.length ? args : ['http://localhost:40404'];
+  const fetch = nodeFetch({ http });
+  const rnode = RNode(fetch);
+  const node = proposer({ admin: url, boot: 'N/A', read: 'N/A' }, rnode, sched);
+  node.startProposing();
+}
+
+if (require.main === module) {
+  main(
+    process.argv.slice(2),
+    {
+      // eslint-disable-next-line global-require
+      http: require('http'),
+    },
+    { setInterval, clearInterval },
+  );
+}
diff --git a/src/rhopm.js b/src/rhopm.js
index 246133b..c5035b0 100644
--- a/src/rhopm.js
+++ b/src/rhopm.js
@@ -3,13 +3,17 @@
 import { nodeFetch } from './curl';
 import { RNode } from './rnode';
 import { startTerm, listenAtDeployId } from './proxy';
+import { proposer } from './proposer';
 
 // @ts-ignore
 const { keys, freeze, fromEntries } = Object;
 
-export const rhoDir = 'rho_modules';
-export const rhoInfoPath = (src) =>
-  `${rhoDir}/${src.replace(/\.rho$/, '.json')}`;
+/* TODO: handle non-posix paths? */
+/** @type {(net: string) => string} */
+export const rhoDir = (net) => `rho_modules/${net}`;
+/** @type {(src: string, net: string) => string} */
+export const rhoInfoPath = (src, net) =>
+  `${rhoDir(net)}/${src.replace(/\.rho$/, '.json')}`;
 export const importPattern = /match\s*\("import",\s*"(?<specifier>[^"]+)",\s*`(?<uri>rho:id:[^`]*)`\)/g;
 
 function log(...args) {
@@ -215,65 +219,43 @@ function parseEnv(txt) {
 }
 
 /**
- *
- * @param {string} envText
+ * @param {Record<string, string | undefined>} env
+ * @param {{ admin?: string, boot: string, read: string }} api
  * @param {typeof import('http')} http
  * @param {SchedulerAccess} sched
- * @param {number} period
+ * @param {number=} period
  *
- * @typedef { {
- *   setInterval: typeof setInterval,
- *   clearInterval: typeof clearInterval,
- * } } SchedulerAccess
+ * @typedef {import('./proposer').SchedulerAccess} SchedulerAccess
  */
-export function shardIO(envText, http, sched, period = 2 * 1000) {
+export function shardAccess(env, api, http, sched, period = 2 * 1000) {
   const fetch = nodeFetch({ http });
-  const env = parseEnv(envText);
-  const api = {
-    admin: `http://${env.MY_NET_IP}:40405`,
-    boot: `http://${env.MY_NET_IP}:40403`,
-    read: `http://${env.MY_NET_IP}:40413`,
-  };
-  const rnode = RNode(fetch);
 
-  const proposer = rnode.admin(api.admin);
-  let proposing = false;
-  let waiters = 0;
-  let pid;
+  const rnode = RNode(fetch);
+  const blockMaker = proposer(api, rnode, sched, period);
 
   return freeze({
     env,
     ...api,
     validator: rnode.validator(api.boot),
     observer: rnode.observer(api.read),
-    startProposing() {
-      waiters += 1;
-      if (typeof pid !== 'undefined') {
-        return;
-      }
-      pid = sched.setInterval(() => {
-        if (!proposing) {
-          proposing = true;
-          proposer
-            .propose()
-            .then(() => {
-              console.log('proposed', { waiters });
-              proposing = false;
-            })
-            .catch((err) => {
-              console.log('propose failed', { waiters, err: err.message });
-              proposing = false;
-            });
-        }
-      }, period);
-    },
-    stopProposing() {
-      if (waiters <= 0) {
-        return;
-      }
-      waiters -= 1;
-      sched.clearInterval(pid);
-      pid = undefined;
-    },
+    ...blockMaker,
   });
 }
+
+/**
+ * Local shard I/O
+ *
+ * @param {string} envText
+ * @param {typeof import('http')} http
+ * @param {SchedulerAccess} sched
+ * @param {number=} period
+ */
+export function shardIO(envText, http, sched, period = 2 * 1000) {
+  const env = parseEnv(envText);
+  const api = {
+    admin: `http://${env.MY_NET_IP}:40405`,
+    boot: `http://${env.MY_NET_IP}:40403`,
+    read: `http://${env.MY_NET_IP}:40413`,
+  };
+  return shardAccess(env, api, http, sched, period);
+}