diff --git a/codex-rs/README.md b/codex-rs/README.md
index e74cdfc2cd..377bcfbbdd 100644
--- a/codex-rs/README.md
+++ b/codex-rs/README.md
@@ -63,6 +63,22 @@ codex completion zsh
 codex completion fish
 ```
 
+### Custom Prompts
+
+Save frequently used prompts as Markdown files and reuse them quickly from the slash menu.
+
+- Location: Put files in `~/.codex/prompts/` (create the folders if they don’t exist).
+- File type: Only Markdown files with the `.md` extension are recognized.
+- Name: The filename without the `.md` extension becomes the slash entry. For a file named `my-prompt.md`, type `/my-prompt`.
+- Content: The file contents are sent as your message when you select the item in the slash popup and press Enter.
+- How to use:
+  - Start a new session (Codex loads custom prompts on session start).
+  - In the composer, type `/` to open the slash popup and begin typing your prompt name.
+  - Use Up/Down to select it. Press Enter to submit its contents, or Tab to autocomplete the name.
+- Notes:
+  - Files with names that collide with built‑in commands (e.g. `/init`) are ignored and won’t appear.
+  - New or changed files are discovered on session start. If you add a new prompt while Codex is running, start a new session to pick it up.
+
 ### Experimenting with the Codex Sandbox
 
 To test to see what happens when a command is run under the sandbox provided by Codex, we provide the following subcommands in Codex CLI: