diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5da8285c..abc9e2ae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- The `rw comment` CLI now stamps comments it creates with the AI identity (`{ id: "local:ai", name: "AI" }`, a sparkles avatar in the viewer) by default, instead of the human `{ id: "local:human", name: "You" }`. The CLI's primary user is an LLM agent, so unattributed agent comments are now visually distinct from a human reviewer's own comments in the browser. Set `RW_COMMENT_AUTHOR_ID`/`RW_COMMENT_AUTHOR_NAME` (or `--author-id`/`--author-name`) to override. Browser-authored comments via `rw serve` are unchanged (still `local:human`).
 - The "Add comment" button that appears when you select text in a doc is now icon-only (a speech-bubble icon) instead of icon + "Add comment" text, for a more compact popover. The button keeps its "Add comment" accessible name, so screen readers and keyboard users are unaffected.
 
 ### Fixed
diff --git a/crates/rw-comments/src/model.rs b/crates/rw-comments/src/model.rs
index fd5d4e89..616bf54d 100644
--- a/crates/rw-comments/src/model.rs
+++ b/crates/rw-comments/src/model.rs
@@ -25,6 +25,20 @@ impl Author {
             avatar_url: None,
         }
     }
+
+    /// The identity stamped on comments created through the `rw comment` CLI
+    /// when the caller supplies no author. The CLI's primary user is an LLM
+    /// agent, so its default is AI — rendered with a sparkles avatar in the
+    /// viewer — rather than [`Author::local_human`], which remains the default
+    /// for browser-authored comments.
+    #[must_use]
+    pub fn local_ai() -> Self {
+        Self {
+            id: "local:ai".to_owned(),
+            name: "AI".to_owned(),
+            avatar_url: None,
+        }
+    }
 }
 
 /// A selector that identifies a text range within a document.
diff --git a/crates/rw/src/commands/comment/add.rs b/crates/rw/src/commands/comment/add.rs
index c0b9eb0d..5479b8fc 100644
--- a/crates/rw/src/commands/comment/add.rs
+++ b/crates/rw/src/commands/comment/add.rs
@@ -55,7 +55,7 @@ pub(crate) async fn run(ctx: &Context, args: AddArgs) -> Result<(), CliError> {
     let input = NewComment {
         document_id,
         parent_id: None,
-        author,
+        author: Some(author),
         body,
         selectors,
         quote: None,
diff --git a/crates/rw/src/commands/comment/identity.rs b/crates/rw/src/commands/comment/identity.rs
index cbac10d6..543c04b2 100644
--- a/crates/rw/src/commands/comment/identity.rs
+++ b/crates/rw/src/commands/comment/identity.rs
@@ -2,27 +2,25 @@ use rw_comments::Author;
 
 use crate::error::CliError;
 
-/// Resolve an optional author claim.
+/// Resolve the author claim for a CLI-created comment.
 ///
 /// Returns:
-/// - `Ok(Some(Author))` when both id and name are provided.
-/// - `Ok(None)` when neither is provided (callers fall back to
-///   [`Author::local_human`]).
-/// - `Err(CliError::Validation)` when exactly one of the two is provided.
-pub(crate) fn resolve_author(
-    id: Option<&str>,
-    name: Option<&str>,
-) -> Result<Option<Author>, CliError> {
+/// - the explicit [`Author`] when both id and name are provided;
+/// - the default [`Author::local_ai`] identity when neither is provided — the
+///   `rw comment` CLI's primary user is an LLM agent, so an unattributed
+///   comment is stamped as AI rather than as a human;
+/// - [`CliError::Validation`] when exactly one of the two is provided.
+pub(crate) fn resolve_author(id: Option<&str>, name: Option<&str>) -> Result<Author, CliError> {
     match (id, name) {
-        (Some(id), Some(name)) => Ok(Some(Author {
+        (Some(id), Some(name)) => Ok(Author {
             id: id.to_owned(),
             name: name.to_owned(),
             avatar_url: None,
-        })),
-        (None, None) => Ok(None),
+        }),
+        (None, None) => Ok(Author::local_ai()),
         _ => Err(CliError::Validation(
             "--author-id and --author-name must be set together (or both left unset \
-             to use the default `local:human` identity)"
+             to use the default `local:ai` identity)"
                 .to_owned(),
         )),
     }
@@ -39,17 +37,17 @@ mod tests {
         let author = resolve_author(Some("local:claude-code"), Some("Claude Code")).unwrap();
         assert_eq!(
             author,
-            Some(Author {
+            Author {
                 id: "local:claude-code".to_owned(),
                 name: "Claude Code".to_owned(),
                 avatar_url: None,
-            })
+            }
         );
     }
 
     #[test]
-    fn neither_set_returns_none() {
-        assert_eq!(resolve_author(None, None).unwrap(), None);
+    fn neither_set_returns_local_ai() {
+        assert_eq!(resolve_author(None, None).unwrap(), Author::local_ai());
     }
 
     #[test]
diff --git a/crates/rw/src/commands/comment/reply.rs b/crates/rw/src/commands/comment/reply.rs
index bcdbe45b..cd278d62 100644
--- a/crates/rw/src/commands/comment/reply.rs
+++ b/crates/rw/src/commands/comment/reply.rs
@@ -40,7 +40,7 @@ pub(crate) async fn run(ctx: &Context, args: ReplyArgs) -> Result<(), CliError>
         .create(CreateComment {
             document_id: parent.document_id.clone(),
             parent_id: Some(parent.id),
-            author,
+            author: Some(author),
             body,
             selectors: Vec::new(),
         })
diff --git a/docs/comment-cli.md b/docs/comment-cli.md
index 7dc8dd12..501505e9 100644
--- a/docs/comment-cli.md
+++ b/docs/comment-cli.md
@@ -63,7 +63,7 @@ New comments carry an `author` stamp. Resolution order:
 
 1. `--author-id` and `--author-name` flags on the subcommand.
 2. `$RW_COMMENT_AUTHOR_ID` and `$RW_COMMENT_AUTHOR_NAME` env vars.
-3. If both are unset, the CLI writes the comment with the default identity `{ id: "local:human", name: "You" }`. (This is the same default `rw serve` uses when the browser writes a comment — viewer and CLI stay aligned.)
+3. If both are unset, the CLI writes the comment with the default identity `{ id: "local:ai", name: "AI" }` — the `rw comment` CLI's primary user is an LLM agent, so an unattributed comment is stamped as AI (a sparkles avatar in the browser) rather than as a human. (Browser-authored comments via `rw serve` still default to `{ id: "local:human", name: "You" }`.)
 
 Set both or neither — a partial identity (e.g. id without name) is rejected before the request leaves the CLI.