diff --git a/crates/engine/src/import_journal_tests.rs b/crates/engine/src/import_journal_tests.rs
new file mode 100644
index 000000000..f8fa84efc
--- /dev/null
+++ b/crates/engine/src/import_journal_tests.rs
@@ -0,0 +1,51 @@
+//! Imported file bytes already live in the document: the command log keeps no second copy.
+
+use base64::Engine as _;
+use serde_json::{Value, json};
+
+use crate::Session;
+
+const SVG: &str = r##"<svg xmlns="http://www.w3.org/2000/svg" width="40" height="20"><rect width="40" height="20" fill="#3366cc"/></svg>"##;
+
+fn payload() -> String {
+    base64::engine::general_purpose::STANDARD.encode(SVG)
+}
+
+fn holds_payload(journal: &[(String, Value)]) -> bool {
+    let payload = payload();
+    journal.iter().any(|(_, params)| params.to_string().contains(&payload))
+}
+
+#[test]
+fn byte_imports_keep_no_payload_in_the_journal() {
+    let mut s = Session::new();
+    let before = s.doc().unwrap().node_count();
+    s.execute("file.import", &json!({"data": payload(), "name": "pasted.svg"})).unwrap();
+    assert!(!holds_payload(&s.journal), "the journal must not retain the Base64 file");
+    // Not journaling is no change to the edit itself: still one undo step.
+    s.execute("edit.undo", &json!({})).unwrap();
+    assert_eq!(s.doc().unwrap().node_count(), before);
+}
+
+#[test]
+fn batch_wrappers_do_not_retain_import_payloads() {
+    let mut s = Session::new();
+    let nested =
+        json!({"command": "command.batch", "params": {"commands": [{"command": "file.import", "params": {"data": payload(), "name": "a.svg"}}]}});
+    s.execute("command.batch", &json!({"commands": [nested]})).unwrap();
+    assert!(!holds_payload(&s.journal));
+}
+
+#[test]
+fn path_imports_and_ordinary_edits_are_still_journaled() {
+    let dir = std::env::temp_dir().join(format!("figcraft-import-journal-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let path = dir.join("kit.svg");
+    std::fs::write(&path, SVG).unwrap();
+    let mut s = Session::new();
+    s.execute("file.import", &json!({"path": path.to_string_lossy()})).unwrap();
+    s.execute("shape.rectangle", &json!({"x": 0, "y": 0, "width": 10, "height": 10})).unwrap();
+    let ids: Vec<_> = s.journal.iter().map(|(id, _)| id.as_str()).collect();
+    assert_eq!(ids, ["file.import", "shape.rectangle"]);
+    std::fs::remove_dir_all(&dir).ok();
+}
diff --git a/crates/engine/src/lib.rs b/crates/engine/src/lib.rs
index 34653bd5f..b84012a6a 100644
--- a/crates/engine/src/lib.rs
+++ b/crates/engine/src/lib.rs
@@ -721,7 +721,8 @@ pub struct Session {
     /// dark page colour while it is dark (added pages take the current page's). Headless sessions (CLI, MCP, exports) have no
     /// theme, so what scripts make is the same everywhere.
     pub ui_dark: Option<bool>,
-    /// Command log (id + params) for actions/automation.
+    /// Command log (id + params) for actions/automation. File imports that carry the file bytes
+    /// (`file.import` with `data`) are not logged, so the log never holds a copy of a pasted file.
     pub journal: Vec<(String, Value)>,
     /// Recently used colours.
     pub recent_colors: Vec<figcraft_color::Color>,
@@ -746,6 +747,19 @@ impl Default for Session {
     }
 }
 
+/// Whether a command, or a batch wrapping one, imports a file passed as Base64 `data`.
+fn command_carries_import_bytes(id: &str, params: &Value) -> bool {
+    match id {
+        "file.import" => params::get(params, "data").is_some(),
+        "command.batch" => params.get("commands").and_then(Value::as_array).is_some_and(|commands| {
+            commands.iter().any(|c| {
+                c.get("command").and_then(Value::as_str).zip(c.get("params")).is_some_and(|(id, params)| command_carries_import_bytes(id, params))
+            })
+        }),
+        _ => false,
+    }
+}
+
 impl Session {
     /// A session with one new document.
     pub fn new() -> Self {
@@ -885,9 +899,13 @@ impl Session {
                 if spec.history && id != "edit.repeat" {
                     self.last_command = Some((id.to_string(), params.clone()));
                 }
-                self.journal.push((id.to_string(), params.clone()));
-                if self.journal.len() > 5000 {
-                    self.journal.drain(..1000);
+                // Imported bytes already live in the document: a Base64 copy in the log would stay
+                // for the whole session.
+                if !command_carries_import_bytes(id, params) {
+                    self.journal.push((id.to_string(), params.clone()));
+                    if self.journal.len() > 5000 {
+                        self.journal.drain(..1000);
+                    }
                 }
             }
             Err(_) => {
@@ -1550,6 +1568,8 @@ mod html_codegen_tests;
 #[cfg(test)]
 mod import_export_tests;
 #[cfg(test)]
+mod import_journal_tests;
+#[cfg(test)]
 mod inspect_behaviour_tests;
 #[cfg(test)]
 mod interaction_rollback_tests;