diff --git a/radicle-cli/src/terminal/args.rs b/radicle-cli/src/terminal/args.rs
index ece18463..c6b56ea4 100644
--- a/radicle-cli/src/terminal/args.rs
+++ b/radicle-cli/src/terminal/args.rs
@@ -2,6 +2,8 @@ use std::ffi::OsString;
 use std::str::FromStr;
 
 use anyhow::anyhow;
+use radicle::crypto;
+use radicle::prelude::Did;
 
 #[derive(thiserror::Error, Debug)]
 pub enum Error {
@@ -71,3 +73,15 @@ pub fn finish(unparsed: Vec<OsString>) -> anyhow::Result<()> {
     }
     Ok(())
 }
+
+pub fn did(val: OsString) -> anyhow::Result<Did> {
+    let val = val.to_string_lossy();
+    let Ok(peer) = Did::from_str(&val) else {
+        if crypto::PublicKey::from_str(&val).is_ok() {
+            return Err(anyhow!("expected DID, did you mean 'did:key:{val}'?"));
+        } else {
+            return Err(anyhow!("invalid DID '{}', expected 'did:key'", val));
+        }
+    };
+    Ok(peer)
+}