diff --git a/9p b/9p
index fc5443e..0a4ca8a 160000
--- a/9p
+++ b/9p
@@ -1 +1 @@
-Subproject commit fc5443e3145c2a008178ebdcdde7b9f82e9c5be7
+Subproject commit 0a4ca8a8690f4f5c9add9dd3627b66e28d404cc8
diff --git a/core b/core
index 269c3ea..aa32d17 160000
--- a/core
+++ b/core
@@ -1 +1 @@
-Subproject commit 269c3eacd5dc223158327958868bd6203296bd30
+Subproject commit aa32d17e818f89361c8fd6bf61ced66dee09b42f
diff --git a/doc/help.md b/doc/help.md
new file mode 100644
index 0000000..f37542c
--- /dev/null
+++ b/doc/help.md
@@ -0,0 +1,78 @@
+# ollie
+
+An AI agent exposed as a filesystem. Mount it, then use shell tools.
+
+## Quick start
+
+```sh
+olliesrv start                                       # start the 9P server
+echo "workdir=$PWD" > ~/mnt/ollie/s/new              # create a session
+ls ~/mnt/ollie/s/                                    # find the session ID
+echo "hello" > ~/mnt/ollie/s/<id>/prompt             # send a prompt
+cat ~/mnt/ollie/s/<id>/chat                          # read the conversation
+tail -f ~/mnt/ollie/s/<id>/chat                      # follow live output
+```
+
+## Filesystem
+
+```
+ollie/
+  a/              agent configs (r/w)        ls, cat, cp, mv, rm
+  backends        available backends (ro)    cat
+  help            this file (ro)             cat
+  p/              prompt templates (r/w)     ls, cat, edit
+  pl/             plans (r/w)                ls, cat, edit
+  s/              sessions                   ls
+    new           create session (w)         echo "workdir=/path" >
+    <id>/         session directory           rm -r to kill; mv to rename
+      agent       active agent (r/w)
+      backend     active backend (r/w)
+      chat        conversation log (ro)
+      ctl         control (w)                stop, kill, clear, compact, rn <name>
+      ctxsz       context size (ro)
+      dequeue     pop queued prompt (ro)
+      enqueue     queue a prompt (w)
+      mcp         MCP servers (ro)
+      model       active model (r/w)
+      models      available models (ro)
+      prompt      submit prompt (w)
+      reply       last reply (ro)
+      state       agent state (ro)           idle | thinking | calling: <tool>
+      usage       token counts (ro)
+      workdir     working directory (r/w)
+  sk/             skills (r/w)               ls, cat, edit
+  t/              tool scripts (r/w)         ls, cat, edit, chmod
+```
+
+## Session management
+
+```sh
+echo "workdir=/path backend=ollama model=qwen3:8b" > ~/mnt/ollie/s/new
+mv ~/mnt/ollie/s/<id> ~/mnt/ollie/s/my-name         # rename
+rm -r ~/mnt/ollie/s/<id>                             # kill
+echo stop > ~/mnt/ollie/s/<id>/ctl                   # interrupt current turn
+```
+
+## Switching backend/model/agent
+
+```sh
+cat ~/mnt/ollie/backends                             # list backends
+cat ~/mnt/ollie/s/<id>/models                        # list models
+echo ollama > ~/mnt/ollie/s/<id>/backend
+echo qwen3:8b > ~/mnt/ollie/s/<id>/model
+echo myagent > ~/mnt/ollie/s/<id>/agent
+```
+
+Writes to backend, model, and agent are rejected while the agent is running.
+
+## Environment
+
+```
+OLLIE_BACKEND       ollama | openai | openrouter | anthropic | copilot | kiro
+OLLIE_MODEL         default model name
+OLLIE_9MOUNT        mount path (default: ~/mnt/ollie)
+OLLIE_TOOLS_PATH    tool scripts directory (default: ~/.config/ollie/tools)
+OLLIE_SKILLS_PATH   skills directory (default: ~/.config/ollie/skills)
+```
+
+Set defaults in `~/.config/ollie/env` (KEY=VALUE, one per line).
diff --git a/mkfile b/mkfile
index 5bcade3..ee309d3 100755
--- a/mkfile
+++ b/mkfile
@@ -31,6 +31,7 @@ data:V:
 	cp -rf prompts/* $HOME/.config/ollie/prompts
 	cp -rf sandbox/* $HOME/.config/ollie/sandbox
 	cp -rf skills/* $HOME/.config/ollie/skills
+	cp doc/help.md $HOME/.config/ollie/help.md
 
 help:V:
 	echo 'Ollie monorepo build targets:'