feat: support arguments in Custom Prompts

codex-rs/core/src/custom_prompts.rs

@@ -63,16 +63,77 @@ pub async fn discover_prompts_in_excluding(
             Ok(s) => s,
             Err(_) => continue,
         };
+        // Extract optional description from simple front matter and strip it from the body.
+        // We support a minimal subset:
+        // ---\n
+        // description: <single line>\n
+        // ---\n
+        let (description, body) = parse_front_matter_description_and_body(&content);
         out.push(CustomPrompt {
             name,
             path,
-            content,
+            content: body,
+            description,
         });
     }
     out.sort_by(|a, b| a.name.cmp(&b.name));
     out
 }
 
+/// Parse a minimal YAML-like front matter from the beginning of `content` and
+/// return `(description, body_without_front_matter)`.
+///
+/// Front matter is recognized only when the very first line is exactly `---` (ignoring
+/// surrounding whitespace), and it ends at the next line that is exactly `---`.
+/// Within the block, if a line with `description:` is present, its value is captured
+/// (with surrounding quotes stripped) and returned.
+/// If front matter is malformed (no closing `---`), returns `(None, content.to_string())`.
+fn parse_front_matter_description_and_body(content: &str) -> (Option<String>, String) {
+    let mut lines_iter = content.lines();
+    match lines_iter.next() {
+        Some(first) if first.trim() == "---" => {}
+        _ => return (None, content.to_string()),
+    }
+
+    let mut desc: Option<String> = None;
+    let mut in_front = true;
+    let mut body_lines: Vec<&str> = Vec::new();
+
+    for line in content.lines().skip(1) {
+        let trimmed = line.trim();
+        if in_front {
+            if trimmed == "---" {
+                in_front = false;
+                continue;
+            }
+            if let Some(rest) = trimmed.strip_prefix("description:") {
+                let mut val = rest.trim().to_string();
+                if (val.starts_with('"') && val.ends_with('"'))
+                    || (val.starts_with('\'') && val.ends_with('\''))
+                {
+                    val = val[1..val.len().saturating_sub(1)].to_string();
+                }
+                if !val.is_empty() {
+                    desc = Some(val);
+                }
+            }
+        } else {
+            body_lines.push(line);
+        }
+    }
+
+    if in_front {
+        // No closing '---'
+        return (None, content.to_string());
+    }
+
+    let mut body = body_lines.join("\n");
+    if content.ends_with('\n') && (!body.is_empty()) {
+        body.push('\n');
+    }
+    (desc, body)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -124,4 +185,17 @@ mod tests {
         let names: Vec<String> = found.into_iter().map(|e| e.name).collect();
         assert_eq!(names, vec!["good"]);
     }
+
+    #[tokio::test]
+    async fn parses_front_matter_description() {
+        let tmp = tempdir().expect("create TempDir");
+        let dir = tmp.path();
+        let content = b"---\ndescription: Hello world\n---\nBody text";
+        fs::write(dir.join("desc.md"), content).unwrap();
+        let found = discover_prompts_in(dir).await;
+        assert_eq!(found.len(), 1);
+        assert_eq!(found[0].name, "desc");
+        assert_eq!(found[0].description.as_deref(), Some("Hello world"));
+        assert_eq!(found[0].content.as_str(), "Body text");
+    }
 }

codex-rs/protocol/src/custom_prompts.rs

@@ -8,4 +8,6 @@ pub struct CustomPrompt {
     pub name: String,
     pub path: PathBuf,
     pub content: String,
+    /// Optional short description (from front matter) to show in the UI popup.
+    pub description: Option<String>,
 }