diff --git a/user/CLAUDE.md b/user/CLAUDE.md
index c05f390..6b790aa 100644
--- a/user/CLAUDE.md
+++ b/user/CLAUDE.md
@@ -126,6 +126,26 @@ tool authenticates.
 Never revoke, rotate or invalidate a credential on your own. That breaks things
 he did not ask you to break.
 
+## Showing him an image: markdown, and a public URL
+
+He reads these sessions through a client that renders markdown — web or the
+phone app. `![](https://…)` is the ONLY way an image reaches him.
+
+Everything else fails, and most of it fails silently:
+
+- reading the file shows it to YOU. He sees nothing.
+- `open`/`xdg-open` opens a viewer on a machine he may not be sitting at.
+- a BARE URL renders as a link on the web client. Always write the `![]()`.
+- a local path in the tag renders nothing. The client fetches over the network,
+  from its own device, so the file has to be somewhere public first.
+
+Known hosts: anything Atelier generated is already served at
+`https://atelier.officer.dev/images/<id>.png`. `oas.officer.dev` is key-gated and
+answers 401 to his client, so it cannot be used for this.
+
+If you have an image he needs to see and nowhere public to put it, say so rather
+than sending a path — a path is indistinguishable from a broken image.
+
 ## Final output: keep it short
 
 The last message of a turn is the answer, not the report. Keep it as short as