diff --git a/crates/automation/src/lib.rs b/crates/automation/src/lib.rs
index d7eb8a2baa..aff732462f 100644
--- a/crates/automation/src/lib.rs
+++ b/crates/automation/src/lib.rs
@@ -703,6 +703,24 @@ impl Automation {
             "content_update" => self.content_update(&a)?,
             "content_delete" => self.content_delete(&a)?,
             "doc_print" => self.doc_print(&a)?,
+            "attachment_add" => {
+                let path = self.resolve(a.str("path")?, false)?;
+                let bytes = std::fs::read(&path).map_err(|e| failed(format!("{}: {e}", path.display())))?;
+                let name = match a.opt_str("name")? {
+                    Some(n) => n.to_string(),
+                    None => path.file_name().map(|n| n.to_string_lossy().into_owned()).unwrap_or_default(),
+                };
+                let mime = pdfcraft_engine::mime_for_name(&name).map(str::to_string);
+                let description = a.opt_str("description")?.map(str::to_string);
+                let before: Vec<String> = self.doc(&a)?.info.attachments.iter().map(|x| x.name.clone()).collect();
+                let out = self.apply(&a, Edit::AddAttachment { name, bytes, description, mime })?;
+                let key = self.doc(&a)?.info.attachments.iter().map(|x| x.name.clone()).find(|n| !before.contains(n)).unwrap_or_default();
+                json!({ "name": key, "document": out })
+            }
+            "attachment_delete" => {
+                let edit = Edit::DeleteAttachment { key: a.str("name")?.into() };
+                self.apply(&a, edit)?
+            }
             "doc_remove_hidden" => self.doc_remove_hidden(&a)?,
             "doc_audit_redactions" => self.doc_audit_redactions(&a)?,
             "fill_sign_add" => self.fill_sign_add(&a)?,
diff --git a/crates/automation/src/tools.rs b/crates/automation/src/tools.rs
index cfdeb1c16f..558b2968ca 100644
--- a/crates/automation/src/tools.rs
+++ b/crates/automation/src/tools.rs
@@ -129,6 +129,12 @@ pub fn tools() -> Vec<ToolDef> {
                 "dpi": {"type":"number","minimum":72,"maximum":600},
                 "language": {"type":"string"}, "skip_text_pages": {"type":"boolean"}
             }), &["paths","out_dir","steps"])),
+        t("attachment_add", "Attach a file", "Attach the file at path to the document (document level, the Attachments panel; not a paper-clip comment on a page). name defaults to the file's name; the attachment's key, unique in the document, is returned. Undoable.")
+            .cmd("edit.attach")
+            .with(schema(json!({"doc": doc(), "path": {"type": "string"}, "name": {"type": "string"}, "description": {"type": "string"}}), &["doc", "path"])),
+        t("attachment_delete", "Delete an attachment", "Remove the document-level attachment with this name (as doc_info lists it). Undoable.")
+            .destructive()
+            .with(schema(json!({"doc": doc(), "name": {"type": "string"}}), &["doc", "name"])),
         t("doc_open", "Open a PDF", "Open a PDF file and return its document id, page count and whether it can be edited.")
             .cmd("file.open")
             .with(schema(json!({ "path": { "type": "string" }, "password": { "type": "string", "description": "User or owner password for encrypted files." } }), &["path"])),
diff --git a/crates/automation/tests/automation.rs b/crates/automation/tests/automation.rs
index 0ff3930b4a..3249cff552 100644
--- a/crates/automation/tests/automation.rs
+++ b/crates/automation/tests/automation.rs
@@ -5672,3 +5672,43 @@ fn absolute_gotor_consent_does_not_bypass_validation_or_passwords() {
     assert_eq!(opened["document"]["encrypted"], true);
     assert_eq!(opened["destination_applied"], true);
 }
+
+#[test]
+fn attaching_and_deleting_files_through_the_tools() {
+    let dir = workdir("attach");
+    std::fs::write(dir.join("notes.txt"), b"keep this with the PDF").unwrap();
+    let mut a = auto(&dir);
+    let doc = ok(&mut a, "doc_open", json!({ "path": "a.pdf" }))["doc"].as_u64().unwrap();
+    assert!(ok(&mut a, "doc_info", json!({ "doc": doc }))["attachments"].as_array().unwrap().is_empty());
+    // A text file and a PDF, the PDF under a name of its own; the second notes.txt is kept apart.
+    let r = ok(&mut a, "attachment_add", json!({ "doc": doc, "path": "notes.txt", "description": "Meeting notes" }));
+    assert_eq!(r["name"], "notes.txt");
+    let r = ok(&mut a, "attachment_add", json!({ "doc": doc, "path": "b.pdf", "name": "annex.pdf" }));
+    assert_eq!(r["name"], "annex.pdf");
+    let r = ok(&mut a, "attachment_add", json!({ "doc": doc, "path": "notes.txt" }));
+    assert_eq!(r["name"], "notes.txt (2)");
+    let listed = ok(&mut a, "doc_info", json!({ "doc": doc }))["attachments"].clone();
+    let names: Vec<&str> = listed.as_array().unwrap().iter().map(|x| x["name"].as_str().unwrap()).collect();
+    assert_eq!(names, ["annex.pdf", "notes.txt", "notes.txt (2)"]);
+    assert_eq!(listed[1]["description"], "Meeting notes");
+    assert_eq!(listed[1]["size"], 22);
+    // Saved and reopened, the attachment is there with its bytes.
+    ok(&mut a, "doc_save", json!({ "doc": doc, "path": "with-notes.pdf" }));
+    let saved = std::fs::read(dir.join("with-notes.pdf")).unwrap();
+    let info = pdfcraft_render::inspect(std::sync::Arc::new(saved.clone()), None).unwrap();
+    let att = info.attachments.iter().find(|x| x.name == "notes.txt").expect("notes.txt is in the file");
+    assert_eq!(pdfcraft_render::attachment_data(&saved, None, att).unwrap(), b"keep this with the PDF");
+    // Deleting one leaves the others; a name that is not there is refused; undo brings it back.
+    ok(&mut a, "attachment_delete", json!({ "doc": doc, "name": "notes.txt" }));
+    let names: Vec<String> = ok(&mut a, "doc_info", json!({ "doc": doc }))["attachments"]
+        .as_array()
+        .unwrap()
+        .iter()
+        .map(|x| x["name"].as_str().unwrap().to_string())
+        .collect();
+    assert_eq!(names, ["annex.pdf", "notes.txt (2)"]);
+    assert!(a.call("attachment_delete", &json!({ "doc": doc, "name": "notes.txt" })).is_err());
+    ok(&mut a, "edit_undo", json!({ "doc": doc }));
+    assert_eq!(ok(&mut a, "doc_info", json!({ "doc": doc }))["attachments"].as_array().unwrap().len(), 3);
+    assert!(a.call("attachment_add", &json!({ "doc": doc, "path": "missing.txt" })).is_err(), "a file that is not there is refused");
+}
diff --git a/crates/engine/src/catalog.rs b/crates/engine/src/catalog.rs
index 991c86a9ca..6f7e25f851 100644
--- a/crates/engine/src/catalog.rs
+++ b/crates/engine/src/catalog.rs
@@ -133,7 +133,7 @@ pub static TOOL_GROUPS: &[ToolGroup] = &[
                     item("Link", "link-2", "edit.link", Ready),
                     item("Bates numbering", "hash", "edit.bates", Ready),
                     item("Background", "palette", "edit.background", Ready),
-                    item("Attach file", "paperclip", "edit.attach", Planned("M12")),
+                    item("Attach file", "paperclip", "edit.attach", Ready),
                 ],
             },
         ],
diff --git a/crates/engine/src/commands.rs b/crates/engine/src/commands.rs
index c3294dc1e2..5fd78441de 100644
--- a/crates/engine/src/commands.rs
+++ b/crates/engine/src/commands.rs
@@ -267,6 +267,7 @@ pub const COMMANDS: &[CommandSpec] = &[
     c("edit.text", "Add text", None, None, Modification, "type"),
     c("edit.edit_text", "Edit text & images", None, None, Modification, "text-cursor-input"),
     c("edit.link", "Add or edit links", None, None, Modification, "link-2"),
+    c("edit.attach", "Attach a file…", EDIT, None, Modification, "paperclip"),
     c("edit.links_from_urls", "Create links from URLs", None, None, Modification, "link-2"),
     c("edit.remove_links", "Remove all links", None, None, Modification, "trash-2"),
     c("edit.bates", "Add Bates numbering…", None, None, Modification, "hash"),
diff --git a/crates/engine/src/lib.rs b/crates/engine/src/lib.rs
index 15c0551b14..97a46bcc06 100644
--- a/crates/engine/src/lib.rs
+++ b/crates/engine/src/lib.rs
@@ -41,7 +41,7 @@ pub use signature_image::{ImageSignaturePreview, SignatureImage};
 pub use signature_scan::{PhotoRect, ScanError, SignaturePhoto, Turn};
 pub use text_preview::TextEditPreview;
 
-pub use pdfcraft_organize::{BoxSpec, FieldConflicts, PageBox, SplitBy, split_ranges};
+pub use pdfcraft_organize::{BoxSpec, FieldConflicts, PageBox, SplitBy, mime_for_name, split_ranges};
 
 /// One file produced by a split: (1-based first page, last page, PDF bytes).
 pub use pdfcraft_organize::LabelStyle;
@@ -197,6 +197,8 @@ fn uses_scripts(edit: &Edit) -> bool {
 fn scope_of(edit: &Edit) -> Scope {
     match edit {
         Edit::SetInfo { .. } => Scope::Metadata,
+        // The Attachments list is read from the whole document.
+        Edit::AddAttachment { .. } | Edit::DeleteAttachment { .. } => Scope::Full,
         // A file attachment also changes the Attachments list.
         Edit::AddAnnotation(a) if matches!(a.shape, Shape::Attachment { .. }) => Scope::Full,
         Edit::AddMeasurement(_)
@@ -1330,6 +1332,18 @@ pub enum Edit {
     },
     /// Document Properties ▸ Initial View (and the language and binding).
     SetInitialView(Box<InitialView>),
+    /// Edit ▸ Attach a file: a document-level attachment (`/Names /EmbeddedFiles`) under
+    /// `name`, made unique; `mime` is the embedded file's `/Subtype` when known.
+    AddAttachment {
+        name: String,
+        bytes: Vec<u8>,
+        description: Option<String>,
+        mime: Option<String>,
+    },
+    /// Remove the document-level attachment whose name-tree key is `key`.
+    DeleteAttachment {
+        key: String,
+    },
     /// Build a tagged structure tree for an untagged, text-only document.
     AutoTagText,
     /// Add alternate text: set (or clear, with `None`) a figure's alternate text. `figure` is
@@ -1813,6 +1827,8 @@ impl Edit {
             Edit::DuplicateField { .. } => Label::of("Duplicate field"),
             Edit::SetTabOrder { .. } | Edit::MoveInTabOrder { .. } => Label::of("Set tab order"),
             Edit::SetInitialView(_) => Label::of("Change initial view"),
+            Edit::AddAttachment { name, .. } => Label::with("Attach {name}", name.as_str()),
+            Edit::DeleteAttachment { key } => Label::with("Delete attachment {key}", key.as_str()),
             Edit::AutoTagText => Label::of("Automatically tag text"),
             Edit::SetAltText { .. } => Label::of("Set alternate text"),
             Edit::SetTagProperty { .. } => Label::of("Change tag properties"),
@@ -2002,6 +2018,8 @@ fn check_permission(edit: &Edit, p: &pdfcraft_cos::Permissions) -> Result<(), Ed
         | Edit::SetTabOrder { .. }
         | Edit::MoveInTabOrder { .. }
         | Edit::SetInitialView(_)
+        | Edit::AddAttachment { .. }
+        | Edit::DeleteAttachment { .. }
         | Edit::AutoTagText
         | Edit::SetAltText { .. }
         | Edit::SetTagProperty { .. }
@@ -2192,6 +2210,10 @@ fn run_edit(doc: &mut pdfcraft_cos::Document, edit: &Edit, cx: &mut EditCtx) ->
         Edit::EraseInk { page, index, path, radius } => {
             pdfcraft_annot::erase_ink(doc, *page, *index, path, *radius, &cx.meta())?;
         }
+        Edit::AddAttachment { name, bytes, description, mime } => {
+            pdfcraft_organize::add_attachment(doc, name, bytes, description.as_deref(), mime.as_deref(), cx.date.as_deref())?;
+        }
+        Edit::DeleteAttachment { key } => pdfcraft_organize::delete_attachment(doc, key)?,
         Edit::ReplaceText { page, quads, text, author, strike, caret } => {
             pdfcraft_annot::add_text_replacement(doc, *page, quads, text, author, strike, caret, &cx.meta())?;
         }
diff --git a/crates/organize/src/attachments.rs b/crates/organize/src/attachments.rs
new file mode 100644
index 0000000000..d785f1a4db
--- /dev/null
+++ b/crates/organize/src/attachments.rs
@@ -0,0 +1,159 @@
+//! Document-level file attachments (Acrobat: Edit ▸ Attach file; the Attachments panel): the
+//! `/Names /EmbeddedFiles` name tree of file specifications, each with its embedded stream.
+//!
+//! A FileAttachment annotation (a paper clip on a page) is a comment and lives in the annot
+//! crate; this is the document level only.
+
+use pdfcraft_cos::{Dict, Document, Object, PdfString, Stream};
+
+use crate::OrganizeError;
+use crate::import::{name_tree_entries, set_attachments};
+
+/// The keys of the document-level attachments, in name-tree order.
+pub fn attachment_keys(doc: &Document) -> Vec<String> {
+    entries(doc).into_iter().map(|(k, _)| PdfString::literal(k).to_text()).collect()
+}
+
+/// Attach `bytes` to the document under `name` (a file name; any folder part is dropped). The
+/// name tree's key is the name, made unique with " (2)", " (3)"… when it is already taken, and
+/// is returned so the caller can find the attachment again. `date` is a PDF date string for the
+/// embedded file's `/ModDate`; `mime` its `/Subtype` when known.
+pub fn add_attachment(
+    doc: &mut Document,
+    name: &str,
+    bytes: &[u8],
+    description: Option<&str>,
+    mime: Option<&str>,
+    date: Option<&str>,
+) -> Result<String, OrganizeError> {
+    let name = file_name(name);
+    if name.is_empty() {
+        return Err(OrganizeError::Invalid("the attachment needs a file name".into()));
+    }
+    let mut all = entries(doc);
+    let taken: Vec<String> = all.iter().map(|(k, _)| PdfString::literal(k.clone()).to_text()).collect();
+    let mut key = name.clone();
+    let mut n = 2;
+    while taken.contains(&key) {
+        key = format!("{name} ({n})");
+        n += 1;
+    }
+
+    let mut params = Dict::new();
+    params.set(b"Size".to_vec(), Object::Int(bytes.len() as i64));
+    if let Some(d) = date {
+        params.set(b"ModDate".to_vec(), Object::String(PdfString::literal(d.as_bytes().to_vec())));
+    }
+    let mut ef = Dict::new();
+    ef.set(b"Type".to_vec(), Object::name("EmbeddedFile"));
+    if let Some(m) = mime.map(str::trim).filter(|m| !m.is_empty()) {
+        ef.set(b"Subtype".to_vec(), Object::Name(m.as_bytes().to_vec()));
+    }
+    ef.set(b"Params".to_vec(), Object::Dict(params));
+    let stream = doc.add(Object::Stream(Stream::flate(ef, bytes)));
+
+    let mut spec = Dict::new();
+    spec.set(b"Type".to_vec(), Object::name("Filespec"));
+    spec.set(b"F".to_vec(), Object::String(PdfString::text(&key)));
+    spec.set(b"UF".to_vec(), Object::String(PdfString::text(&key)));
+    if let Some(d) = description.map(str::trim).filter(|d| !d.is_empty()) {
+        spec.set(b"Desc".to_vec(), Object::String(PdfString::text(d)));
+    }
+    let mut files = Dict::new();
+    files.set(b"F".to_vec(), Object::Ref(stream));
+    files.set(b"UF".to_vec(), Object::Ref(stream));
+    spec.set(b"EF".to_vec(), Object::Dict(files));
+    let spec = doc.add(spec);
+
+    all.push((PdfString::text(&key).bytes, Object::Ref(spec)));
+    set_attachments(doc, all)?;
+    Ok(key)
+}
+
+/// Remove the document-level attachment whose name-tree key is `key`. The embedded stream is
+/// left for the writer's garbage collection, as with every other removal.
+pub fn delete_attachment(doc: &mut Document, key: &str) -> Result<(), OrganizeError> {
+    let mut all = entries(doc);
+    let before = all.len();
+    all.retain(|(k, _)| PdfString::literal(k.clone()).to_text() != key);
+    if all.len() == before {
+        return Err(OrganizeError::Invalid(format!("there is no attachment named {key}")));
+    }
+    if all.is_empty() { clear_embedded_files(doc) } else { set_attachments(doc, all) }
+}
+
+/// The `/EmbeddedFiles` entries (key, file specification), in tree order.
+fn entries(doc: &Document) -> Vec<(Vec<u8>, Object)> {
+    let Some(tree) = doc
+        .root()
+        .and_then(|r| doc.get(r).as_dict().cloned())
+        .and_then(|c| c.get(b"Names").map(|n| doc.resolve(n)))
+        .and_then(|n| n.as_dict().and_then(|d| d.get(b"EmbeddedFiles").cloned()))
+    else {
+        return Vec::new();
+    };
+    let mut out = Vec::new();
+    name_tree_entries(doc, &tree, 0, &mut out);
+    out
+}
+
+/// Drop `/EmbeddedFiles` from the catalog's `/Names` (and `/Names` itself when nothing is left).
+fn clear_embedded_files(doc: &mut Document) -> Result<(), OrganizeError> {
+    let root = doc.root().ok_or(OrganizeError::NoPageTree)?;
+    let names = doc.get(root).as_dict().and_then(|c| c.get(b"Names").cloned());
+    match names {
+        Some(Object::Ref(r)) => {
+            doc.update_dict(r, |n| {
+                n.remove(b"EmbeddedFiles");
+            })?;
+        }
+        Some(Object::Dict(mut n)) => {
+            n.remove(b"EmbeddedFiles");
+            doc.update_dict(root, |c| {
+                if n.is_empty() {
+                    c.remove(b"Names");
+                } else {
+                    c.set(b"Names".to_vec(), Object::Dict(n));
+                }
+            })?;
+        }
+        _ => {}
+    }
+    Ok(())
+}
+
+/// The last path component of `name`, trimmed: a dragged-in path or a folder part never becomes
+/// the attachment's name.
+fn file_name(name: &str) -> String {
+    name.rsplit(['/', '\\']).next().unwrap_or(name).trim().to_string()
+}
+
+/// A media type from the file's extension, for the embedded file's `/Subtype`; `None` when it
+/// is not one of the common kinds (the attachment is still fine without it).
+pub fn mime_for_name(name: &str) -> Option<&'static str> {
+    let ext = name.rsplit_once('.').map(|(_, e)| e.to_ascii_lowercase())?;
+    Some(match ext.as_str() {
+        "pdf" => "application/pdf",
+        "txt" | "log" | "md" => "text/plain",
+        "csv" => "text/csv",
+        "htm" | "html" => "text/html",
+        "xml" => "text/xml",
+        "json" => "application/json",
+        "zip" => "application/zip",
+        "png" => "image/png",
+        "jpg" | "jpeg" => "image/jpeg",
+        "gif" => "image/gif",
+        "tif" | "tiff" => "image/tiff",
+        "svg" => "image/svg+xml",
+        "doc" => "application/msword",
+        "docx" => "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+        "xls" => "application/vnd.ms-excel",
+        "xlsx" => "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+        "ppt" => "application/vnd.ms-powerpoint",
+        "pptx" => "application/vnd.openxmlformats-officedocument.presentationml.presentation",
+        "rtf" => "application/rtf",
+        "eml" => "message/rfc822",
+        "msg" => "application/vnd.ms-outlook",
+        _ => return None,
+    })
+}
diff --git a/crates/organize/src/import.rs b/crates/organize/src/import.rs
index c420d2d59c..37684882c6 100644
--- a/crates/organize/src/import.rs
+++ b/crates/organize/src/import.rs
@@ -486,7 +486,7 @@ fn name_tree_lookup(src: &Document, node: &Object, key: &[u8], depth: u8) -> Opt
 }
 
 /// All (key, value) pairs of a name tree, in order.
-fn name_tree_entries(src: &Document, node: &Object, depth: u8, out: &mut Vec<(Vec<u8>, Object)>) {
+pub(crate) fn name_tree_entries(src: &Document, node: &Object, depth: u8, out: &mut Vec<(Vec<u8>, Object)>) {
     if depth > 32 {
         return;
     }
@@ -1075,18 +1075,24 @@ fn collect_attachments(dst: &mut Document, src: &Document, out: &mut Vec<(Vec<u8
 }
 
 /// Write attachments as a flat, sorted `/EmbeddedFiles` name tree; duplicate names get " (2)"…
-fn set_attachments(dst: &mut Document, mut entries: Vec<(Vec<u8>, Object)>) -> Result<(), OrganizeError> {
+pub(crate) fn set_attachments(dst: &mut Document, mut entries: Vec<(Vec<u8>, Object)>) -> Result<(), OrganizeError> {
     if entries.is_empty() {
         return Ok(());
     }
+    // Names are compared and numbered as text: a key written as UTF-16 (a name with an accent
+    // or Chinese letters) must not get ASCII bytes appended to it.
     let mut seen = std::collections::HashSet::new();
     for (k, _) in entries.iter_mut() {
-        let base = k.clone();
+        let base = pdfcraft_cos::PdfString::literal(k.clone()).to_text();
+        let mut text = base.clone();
         let mut n = 2;
-        while !seen.insert(k.clone()) {
-            *k = [base.as_slice(), format!(" ({n})").as_bytes()].concat();
+        while !seen.insert(text.clone()) {
+            text = format!("{base} ({n})");
             n += 1;
         }
+        if text != base {
+            *k = pdfcraft_cos::PdfString::text(&text).bytes;
+        }
     }
     entries.sort_by(|a, b| a.0.cmp(&b.0));
     let mut names = Vec::new();
@@ -1098,6 +1104,14 @@ fn set_attachments(dst: &mut Document, mut entries: Vec<(Vec<u8>, Object)>) -> R
     tree.set(b"Names".to_vec(), Object::Array(names));
     let tree = dst.add(tree);
     let root = dst.root().ok_or(OrganizeError::NoPageTree)?;
+    // `/Names` may be an indirect dictionary (Acrobat writes it so): update it where it is, so
+    // its other trees (/Dests, /JavaScript…) stay.
+    if let Some(Object::Ref(names)) = dst.get(root).as_dict().and_then(|c| c.get(b"Names").cloned())
+        && dst.get(names).as_dict().is_some()
+    {
+        dst.update_dict(names, |n| n.set(b"EmbeddedFiles".to_vec(), Object::Ref(tree)))?;
+        return Ok(());
+    }
     dst.update_dict(root, |c| {
         let mut n = match c.get(b"Names") {
             Some(Object::Dict(d)) => d.clone(),
diff --git a/crates/organize/src/lib.rs b/crates/organize/src/lib.rs
index 7b366bad9d..f008bb11b6 100644
--- a/crates/organize/src/lib.rs
+++ b/crates/organize/src/lib.rs
@@ -13,6 +13,7 @@
 
 use pdfcraft_cos::{Dict, Document, ObjRef, Object, PdfString};
 
+mod attachments;
 mod boxes;
 mod dedupe;
 mod import;
@@ -23,6 +24,7 @@ mod prune;
 pub mod view;
 mod xmp;
 
+pub use attachments::{add_attachment, attachment_keys, delete_attachment, mime_for_name};
 pub use boxes::{BoxSpec, PageBox, page_boxes, set_page_box};
 pub use dedupe::dedupe_resources;
 pub use import::{
diff --git a/crates/organize/src/tests.rs b/crates/organize/src/tests.rs
index e07af72a1c..4bb3b1e653 100644
--- a/crates/organize/src/tests.rs
+++ b/crates/organize/src/tests.rs
@@ -2441,3 +2441,84 @@ fn combine_field_conflicts_previews_each_file_in_order() {
     assert_eq!(preview[1], [("Text1".to_string(), "Text1-1".to_string())]);
     assert_eq!(preview[2], [("Text1".to_string(), "Text1-2".to_string())], "the cascade continues past the earlier rename");
 }
+
+/// What Edit ▸ Attach file added survives Combine files (upstream's writer), names
+/// with accents included, and the combined document takes more attachments and deletions.
+#[test]
+fn attachments_added_in_the_app_survive_combine_and_more_can_be_attached() {
+    let embedded = |doc: &Document, key: &str| -> (Vec<u8>, Option<String>) {
+        let names = doc.resolve(catalog(doc).get(b"Names").unwrap()).as_dict().cloned().unwrap();
+        let tree = doc.resolve(names.get(b"EmbeddedFiles").unwrap()).as_dict().cloned().unwrap();
+        let pairs = tree.get(b"Names").and_then(|n| n.as_array()).cloned().unwrap();
+        let at = pairs.chunks(2).position(|p| p[0].as_string().unwrap().to_text() == key).unwrap_or_else(|| panic!("no attachment {key}"));
+        let spec = doc.resolve(&pairs[at * 2 + 1]).as_dict().cloned().unwrap();
+        let desc = spec.get(b"Desc").and_then(Object::as_string).map(|s| s.to_text());
+        let ef = spec.get(b"EF").and_then(Object::as_dict).unwrap().get(b"F").cloned().unwrap();
+        let Object::Stream(stream) = doc.resolve(&ef).as_ref().clone() else { panic!("the embedded file is a stream") };
+        (stream.decoded().unwrap(), desc)
+    };
+    let mut a = Document::open(Arc::new(fixture())).unwrap();
+    add_attachment(&mut a, "invoice.csv", b"a,b", Some("March"), Some("text/csv"), None).unwrap();
+    add_attachment(&mut a, "año.txt", b"uno", None, None, None).unwrap();
+    let mut b = Document::open(Arc::new(fixture())).unwrap();
+    add_attachment(&mut b, "invoice.csv", b"x,y", None, None, None).unwrap();
+    add_attachment(&mut b, "año.txt", b"dos", None, None, None).unwrap();
+    let a = save_and_reopen(&a);
+    let b = save_and_reopen(&b);
+    let mut out = full_roundtrip(&combine(&[("A", &a), ("B", &b)]).unwrap());
+    // Both files' attachments, the second copies numbered as text (not bytes glued onto UTF-16).
+    assert_eq!(attachment_keys(&out), ["invoice.csv", "invoice.csv (2)", "año.txt", "año.txt (2)"]);
+    assert_eq!(embedded(&out, "invoice.csv"), (b"a,b".to_vec(), Some("March".into())));
+    assert_eq!(embedded(&out, "invoice.csv (2)"), (b"x,y".to_vec(), None));
+    assert_eq!(embedded(&out, "año.txt (2)").0, b"dos");
+    // The combined document goes on taking attachments, and losing them, like any other.
+    assert_eq!(add_attachment(&mut out, "invoice.csv", b"z", None, None, None).unwrap(), "invoice.csv (3)");
+    delete_attachment(&mut out, "invoice.csv (2)").unwrap();
+    let out = full_roundtrip(&out);
+    assert_eq!(attachment_keys(&out), ["invoice.csv", "invoice.csv (3)", "año.txt", "año.txt (2)"]);
+    assert_eq!(embedded(&out, "invoice.csv (3)").0, b"z");
+}
+
+#[test]
+fn attachments_are_added_listed_and_deleted() {
+    let mut doc = Document::open(Arc::new(fixture())).unwrap();
+    assert!(attachment_keys(&doc).is_empty());
+    // A path loses its folder; the key is the file name.
+    let key = add_attachment(&mut doc, "/Users/eva/Desktop/invoice.csv", b"a,b\n1,2\n", Some("March"), Some("text/csv"), Some("D:20261012120000Z"))
+        .unwrap();
+    assert_eq!(key, "invoice.csv");
+    // The same name again is kept apart.
+    assert_eq!(add_attachment(&mut doc, "invoice.csv", b"x", None, None, None).unwrap(), "invoice.csv (2)");
+    assert_eq!(add_attachment(&mut doc, "  ", b"x", None, None, None), Err(OrganizeError::Invalid("the attachment needs a file name".into())));
+    let doc = save_and_reopen(&doc);
+    assert_eq!(attachment_keys(&doc), ["invoice.csv", "invoice.csv (2)"]);
+    // What was written: a Filespec with the embedded stream, its size and type, and the description.
+    let root = doc.root().unwrap();
+    let names = doc.get(root).as_dict().unwrap().get(b"Names").cloned().unwrap();
+    let tree = doc.resolve(&names).as_dict().unwrap().get(b"EmbeddedFiles").cloned().unwrap();
+    let tree = doc.resolve(&tree);
+    let pairs = tree.as_dict().unwrap().get(b"Names").cloned().unwrap();
+    let pairs = doc.resolve(&pairs).as_array().cloned().unwrap();
+    assert_eq!(pairs.len(), 4);
+    let spec = doc.resolve(&pairs[1]);
+    let spec = spec.as_dict().unwrap();
+    assert_eq!(spec.get(b"Type"), Some(&Object::name("Filespec")));
+    assert_eq!(spec.get(b"UF").and_then(Object::as_string).map(PdfString::to_text).as_deref(), Some("invoice.csv"));
+    assert_eq!(spec.get(b"Desc").and_then(Object::as_string).map(PdfString::to_text).as_deref(), Some("March"));
+    let ef = spec.get(b"EF").and_then(Object::as_dict).unwrap().get(b"F").cloned().unwrap();
+    let ef = doc.resolve(&ef);
+    let Object::Stream(stream) = ef.as_ref() else { panic!("the embedded file is a stream") };
+    assert_eq!(stream.dict.get(b"Subtype"), Some(&Object::Name(b"text/csv".to_vec())));
+    let params = stream.dict.get(b"Params").and_then(Object::as_dict).unwrap();
+    assert_eq!(params.get(b"Size"), Some(&Object::Int(8)));
+    assert_eq!(stream.decoded().unwrap(), b"a,b\n1,2\n");
+    // Deleting: the one named goes, the other stays; the last one takes the tree with it.
+    let mut doc = doc;
+    delete_attachment(&mut doc, "invoice.csv").unwrap();
+    assert_eq!(attachment_keys(&doc), ["invoice.csv (2)"]);
+    assert_eq!(delete_attachment(&mut doc, "invoice.csv"), Err(OrganizeError::Invalid("there is no attachment named invoice.csv".into())));
+    delete_attachment(&mut doc, "invoice.csv (2)").unwrap();
+    let doc = save_and_reopen(&doc);
+    assert!(attachment_keys(&doc).is_empty());
+    assert!(doc.get(doc.root().unwrap()).as_dict().unwrap().get(b"Names").is_none());
+}
diff --git a/crates/ui-egui/src/commands.rs b/crates/ui-egui/src/commands.rs
index 7d7b6b9c58..75dd719594 100644
--- a/crates/ui-egui/src/commands.rs
+++ b/crates/ui-egui/src/commands.rs
@@ -185,6 +185,7 @@ impl PdfCraftApp {
                 self.protect_draft = Default::default();
                 self.dialog = Some(Dialog::Protect);
             }
+            "edit.attach" => self.attach_file_dialog(),
             "protect.remove" => {
                 if self.apply_edit(Edit::RemoveProtection) {
                     self.notify_tr("Security will be removed when you save");
diff --git a/crates/ui-egui/src/i18n/ar.tsv b/crates/ui-egui/src/i18n/ar.tsv
index 222865d72b..0b2b8eed60 100644
--- a/crates/ui-egui/src/i18n/ar.tsv
+++ b/crates/ui-egui/src/i18n/ar.tsv
@@ -2373,3 +2373,8 @@ animation effects	Off	معطّلة
 	This document is trying to open a local file:	يحاول هذا المستند فتح ملف محلي:
 	Move tag earlier	نقل العلامة للأعلى
 	Move tag later	نقل العلامة للأسفل
+	Attach a file…	إرفاق ملف…
+	Delete attachment	حذف المرفق
+	Attaching files is not available on the web yet	إرفاق الملفات غير متاح على الويب بعد
+	Attach {name}	إرفاق {name}
+	Delete attachment {key}	حذف المرفق {key}
diff --git a/crates/ui-egui/src/i18n/bg.tsv b/crates/ui-egui/src/i18n/bg.tsv
index 17a0890fa5..73ae509bc1 100644
--- a/crates/ui-egui/src/i18n/bg.tsv
+++ b/crates/ui-egui/src/i18n/bg.tsv
@@ -2315,3 +2315,8 @@ animation effects	Off	Изключени
 	This document is trying to open a local file:	Този документ се опитва да отвори локален файл:
 	Move tag earlier	Преместване на етикета по-рано
 	Move tag later	Преместване на етикета по-късно
+	Attach a file…	Прикачване на файл…
+	Delete attachment	Изтриване на прикачения файл
+	Attaching files is not available on the web yet	Прикачването на файлове още не е налично в уеб версията
+	Attach {name}	Прикачване на {name}
+	Delete attachment {key}	Изтриване на прикачения файл {key}
diff --git a/crates/ui-egui/src/i18n/cs.tsv b/crates/ui-egui/src/i18n/cs.tsv
index e6e29c8bba..5d78d54720 100644
--- a/crates/ui-egui/src/i18n/cs.tsv
+++ b/crates/ui-egui/src/i18n/cs.tsv
@@ -2426,3 +2426,8 @@ animation effects	Off	Vypnuto
 	This document is trying to open a local file:	Tento dokument se pokouší otevřít místní soubor:
 	Move tag earlier	Přesunout značku dříve
 	Move tag later	Přesunout značku později
+	Attach a file…	Připojit soubor…
+	Delete attachment	Odstranit přílohu
+	Attaching files is not available on the web yet	Připojování souborů zatím na webu není k dispozici
+	Attach {name}	Připojit {name}
+	Delete attachment {key}	Odstranit přílohu {key}
diff --git a/crates/ui-egui/src/i18n/de.tsv b/crates/ui-egui/src/i18n/de.tsv
index 38ef665d13..b75f4913af 100644
--- a/crates/ui-egui/src/i18n/de.tsv
+++ b/crates/ui-egui/src/i18n/de.tsv
@@ -2353,3 +2353,8 @@ animation effects	Off	Aus
 	This document is trying to open a local file:	Dieses Dokument versucht, eine lokale Datei zu öffnen:
 	Move tag earlier	Tag früher verschieben
 	Move tag later	Tag später verschieben
+	Attach a file…	Datei anhängen…
+	Delete attachment	Anhang löschen
+	Attaching files is not available on the web yet	Dateien anhängen ist im Web noch nicht verfügbar
+	Attach {name}	{name} anhängen
+	Delete attachment {key}	Anhang {key} löschen
diff --git a/crates/ui-egui/src/i18n/el.tsv b/crates/ui-egui/src/i18n/el.tsv
index 106278f012..b66a1bc6d2 100644
--- a/crates/ui-egui/src/i18n/el.tsv
+++ b/crates/ui-egui/src/i18n/el.tsv
@@ -2362,3 +2362,8 @@ animation effects	Off	Ανενεργά
 	This document is trying to open a local file:	Αυτό το έγγραφο προσπαθεί να ανοίξει ένα τοπικό αρχείο:
 	Move tag earlier	Μετακίνηση ετικέτας νωρίτερα
 	Move tag later	Μετακίνηση ετικέτας αργότερα
+	Attach a file…	Επισύναψη αρχείου…
+	Delete attachment	Διαγραφή συνημμένου
+	Attaching files is not available on the web yet	Η επισύναψη αρχείων δεν είναι ακόμη διαθέσιμη στον ιστό
+	Attach {name}	Επισύναψη {name}
+	Delete attachment {key}	Διαγραφή συνημμένου {key}
diff --git a/crates/ui-egui/src/i18n/es.tsv b/crates/ui-egui/src/i18n/es.tsv
index 5afbe4f2ef..43bbbbc35b 100644
--- a/crates/ui-egui/src/i18n/es.tsv
+++ b/crates/ui-egui/src/i18n/es.tsv
@@ -2482,3 +2482,8 @@ animation effects	Off	Desactivados
 	This document is trying to open a local file:	Este documento intenta abrir un archivo local:
 	Move tag earlier	Mover etiqueta antes
 	Move tag later	Mover etiqueta después
+	Attach a file…	Adjuntar un archivo…
+	Delete attachment	Eliminar adjunto
+	Attaching files is not available on the web yet	Adjuntar archivos aún no está disponible en la web
+	Attach {name}	Adjuntar {name}
+	Delete attachment {key}	Eliminar adjunto {key}
diff --git a/crates/ui-egui/src/i18n/fr.tsv b/crates/ui-egui/src/i18n/fr.tsv
index 79389837d3..c2c3beec26 100644
--- a/crates/ui-egui/src/i18n/fr.tsv
+++ b/crates/ui-egui/src/i18n/fr.tsv
@@ -2352,3 +2352,8 @@ animation effects	Off	Désactivés
 	This document is trying to open a local file:	Ce document tente d’ouvrir un fichier local :
 	Move tag earlier	Déplacer la balise plus tôt
 	Move tag later	Déplacer la balise plus tard
+	Attach a file…	Joindre un fichier…
+	Delete attachment	Supprimer la pièce jointe
+	Attaching files is not available on the web yet	Joindre des fichiers n'est pas encore disponible sur le web
+	Attach {name}	Joindre {name}
+	Delete attachment {key}	Supprimer la pièce jointe {key}
diff --git a/crates/ui-egui/src/i18n/hu.tsv b/crates/ui-egui/src/i18n/hu.tsv
index 3d6e1e3af5..9d215c571a 100644
--- a/crates/ui-egui/src/i18n/hu.tsv
+++ b/crates/ui-egui/src/i18n/hu.tsv
@@ -2351,3 +2351,8 @@ animation effects	Off	Ki
 	This document is trying to open a local file:	Ez a dokumentum egy helyi fájlt próbál megnyitni:
 	Move tag earlier	Címke korábbra helyezése
 	Move tag later	Címke későbbre helyezése
+	Attach a file…	Fájl csatolása…
+	Delete attachment	Melléklet törlése
+	Attaching files is not available on the web yet	Fájlok csatolása a weben még nem érhető el
+	Attach {name}	{name} csatolása
+	Delete attachment {key}	{key} melléklet törlése
diff --git a/crates/ui-egui/src/i18n/it.tsv b/crates/ui-egui/src/i18n/it.tsv
index 3575ab374d..282db62fcc 100644
--- a/crates/ui-egui/src/i18n/it.tsv
+++ b/crates/ui-egui/src/i18n/it.tsv
@@ -2361,3 +2361,8 @@ animation effects	Off	Disattivati
 	This document is trying to open a local file:	Questo documento sta tentando di aprire un file locale:
 	Move tag earlier	Sposta tag prima
 	Move tag later	Sposta tag dopo
+	Attach a file…	Allega un file…
+	Delete attachment	Elimina allegato
+	Attaching files is not available on the web yet	Allegare file non è ancora disponibile sul web
+	Attach {name}	Allega {name}
+	Delete attachment {key}	Elimina allegato {key}
diff --git a/crates/ui-egui/src/i18n/ja.tsv b/crates/ui-egui/src/i18n/ja.tsv
index 5e61802c35..a33b764e7d 100644
--- a/crates/ui-egui/src/i18n/ja.tsv
+++ b/crates/ui-egui/src/i18n/ja.tsv
@@ -2352,3 +2352,8 @@ animation effects	Off	オフ
 	This document is trying to open a local file:	この文書はローカルファイルを開こうとしています：
 	Move tag earlier	タグを前へ移動
 	Move tag later	タグを後へ移動
+	Attach a file…	ファイルを添付…
+	Delete attachment	添付ファイルを削除
+	Attaching files is not available on the web yet	Web 版ではまだファイルを添付できません
+	Attach {name}	{name} を添付
+	Delete attachment {key}	添付ファイル {key} を削除
diff --git a/crates/ui-egui/src/i18n/kk.tsv b/crates/ui-egui/src/i18n/kk.tsv
index 8e4a090403..5d76591339 100644
--- a/crates/ui-egui/src/i18n/kk.tsv
+++ b/crates/ui-egui/src/i18n/kk.tsv
@@ -2350,3 +2350,8 @@ animation effects	Off	Өшірулі
 	This document is trying to open a local file:	Бұл құжат жергілікті файлды ашуға әрекеттеніп жатыр:
 	Move tag earlier	Тегті ертерек жылжыту
 	Move tag later	Тегті кейінірек жылжыту
+	Attach a file…	Файл тіркеу…
+	Delete attachment	Тіркемені жою
+	Attaching files is not available on the web yet	Вебте файл тіркеу әзірге қолжетімсіз
+	Attach {name}	{name} тіркеу
+	Delete attachment {key}	{key} тіркемесін жою
diff --git a/crates/ui-egui/src/i18n/lt.tsv b/crates/ui-egui/src/i18n/lt.tsv
index ae61e396ff..410bd7c7b5 100644
--- a/crates/ui-egui/src/i18n/lt.tsv
+++ b/crates/ui-egui/src/i18n/lt.tsv
@@ -2596,3 +2596,8 @@ key	Space	Tarpas
 	This document is trying to open a local file:	Šis dokumentas bando atverti vietinį failą:
 	Move tag earlier	Perkelti žymą anksčiau
 	Move tag later	Perkelti žymą vėliau
+	Attach a file…	Pridėti failą…
+	Delete attachment	Ištrinti priedą
+	Attaching files is not available on the web yet	Failų pridėjimas žiniatinklyje dar negalimas
+	Attach {name}	Pridėti {name}
+	Delete attachment {key}	Ištrinti priedą {key}
diff --git a/crates/ui-egui/src/i18n/pl.tsv b/crates/ui-egui/src/i18n/pl.tsv
index 310a990f7d..395b905033 100644
--- a/crates/ui-egui/src/i18n/pl.tsv
+++ b/crates/ui-egui/src/i18n/pl.tsv
@@ -2332,3 +2332,8 @@ animation effects	Off	Wyłączone
 	This document is trying to open a local file:	Ten dokument próbuje otworzyć plik lokalny:
 	Move tag earlier	Przenieś znacznik wcześniej
 	Move tag later	Przenieś znacznik później
+	Attach a file…	Dołącz plik…
+	Delete attachment	Usuń załącznik
+	Attaching files is not available on the web yet	Dołączanie plików nie jest jeszcze dostępne w wersji webowej
+	Attach {name}	Dołącz {name}
+	Delete attachment {key}	Usuń załącznik {key}
diff --git a/crates/ui-egui/src/i18n/pt-br.tsv b/crates/ui-egui/src/i18n/pt-br.tsv
index 623d69ce80..cd6da1c53c 100644
--- a/crates/ui-egui/src/i18n/pt-br.tsv
+++ b/crates/ui-egui/src/i18n/pt-br.tsv
@@ -2366,3 +2366,8 @@ animation effects	Off	Desativados
 	This document is trying to open a local file:	Este documento está tentando abrir um arquivo local:
 	Move tag earlier	Mover tag para antes
 	Move tag later	Mover tag para depois
+	Attach a file…	Anexar um arquivo…
+	Delete attachment	Excluir anexo
+	Attaching files is not available on the web yet	Anexar arquivos ainda não está disponível na web
+	Attach {name}	Anexar {name}
+	Delete attachment {key}	Excluir anexo {key}
diff --git a/crates/ui-egui/src/i18n/ru.tsv b/crates/ui-egui/src/i18n/ru.tsv
index 7f628088d6..cc7c4d2b24 100644
--- a/crates/ui-egui/src/i18n/ru.tsv
+++ b/crates/ui-egui/src/i18n/ru.tsv
@@ -2265,3 +2265,8 @@ animation effects	Off	Выкл
 	This document is trying to open a local file:	Этот документ пытается открыть локальный файл:
 	Move tag earlier	Переместить тег раньше
 	Move tag later	Переместить тег позже
+	Attach a file…	Прикрепить файл…
+	Delete attachment	Удалить вложение
+	Attaching files is not available on the web yet	Прикрепление файлов в веб-версии пока недоступно
+	Attach {name}	Прикрепить {name}
+	Delete attachment {key}	Удалить вложение {key}
diff --git a/crates/ui-egui/src/i18n/sl.tsv b/crates/ui-egui/src/i18n/sl.tsv
index 3feaad354d..1ef69378f1 100644
--- a/crates/ui-egui/src/i18n/sl.tsv
+++ b/crates/ui-egui/src/i18n/sl.tsv
@@ -2357,3 +2357,8 @@ animation effects	Off	Izklopljeni
 	This document is trying to open a local file:	Ta dokument poskuša odpreti lokalno datoteko:
 	Move tag earlier	Premakni oznako prej
 	Move tag later	Premakni oznako pozneje
+	Attach a file…	Priloži datoteko…
+	Delete attachment	Izbriši prilogo
+	Attaching files is not available on the web yet	Prilaganje datotek na spletu še ni na voljo
+	Attach {name}	Priloži {name}
+	Delete attachment {key}	Izbriši prilogo {key}
diff --git a/crates/ui-egui/src/i18n/te.tsv b/crates/ui-egui/src/i18n/te.tsv
index d15365f3d4..4ef063f9b6 100644
--- a/crates/ui-egui/src/i18n/te.tsv
+++ b/crates/ui-egui/src/i18n/te.tsv
@@ -2265,3 +2265,8 @@ animation effects	Off	ఆఫ్
 	This document is trying to open a local file:	ఈ పత్రం ఒక స్థానిక ఫైల్‌ను తెరవడానికి ప్రయత్నిస్తోంది:
 	Move tag earlier	ట్యాగ్‌ను ముందుకు తరలించు
 	Move tag later	ట్యాగ్‌ను వెనుకకు తరలించు
+	Attach a file…	ఫైల్‌ను జోడించు…
+	Delete attachment	జోడింపును తొలగించు
+	Attaching files is not available on the web yet	వెబ్‌లో ఫైల్‌లను జోడించడం ఇంకా అందుబాటులో లేదు
+	Attach {name}	{name}ను జోడించు
+	Delete attachment {key}	జోడింపు {key}ను తొలగించు
diff --git a/crates/ui-egui/src/i18n/tr.tsv b/crates/ui-egui/src/i18n/tr.tsv
index 44fd05f074..eed722a897 100644
--- a/crates/ui-egui/src/i18n/tr.tsv
+++ b/crates/ui-egui/src/i18n/tr.tsv
@@ -2348,3 +2348,8 @@ animation effects	Off	Kapalı
 	This document is trying to open a local file:	Bu belge yerel bir dosya açmaya çalışıyor:
 	Move tag earlier	Etiketi daha erken taşı
 	Move tag later	Etiketi daha geç taşı
+	Attach a file…	Dosya ekle…
+	Delete attachment	Eki sil
+	Attaching files is not available on the web yet	Dosya eklemek web'de henüz kullanılamıyor
+	Attach {name}	{name} ekle
+	Delete attachment {key}	{key} ekini sil
diff --git a/crates/ui-egui/src/i18n/uk.tsv b/crates/ui-egui/src/i18n/uk.tsv
index 648dc855fe..c77239d528 100644
--- a/crates/ui-egui/src/i18n/uk.tsv
+++ b/crates/ui-egui/src/i18n/uk.tsv
@@ -2374,3 +2374,8 @@ animation effects	Off	Вимкнено
 	This document is trying to open a local file:	Цей документ намагається відкрити локальний файл:
 	Move tag earlier	Перемістити тег раніше
 	Move tag later	Перемістити тег пізніше
+	Attach a file…	Прикріпити файл…
+	Delete attachment	Видалити вкладення
+	Attaching files is not available on the web yet	Прикріплення файлів у веб-версії поки недоступне
+	Attach {name}	Прикріпити {name}
+	Delete attachment {key}	Видалити вкладення {key}
diff --git a/crates/ui-egui/src/i18n/zh-hans.tsv b/crates/ui-egui/src/i18n/zh-hans.tsv
index 391c8eda7c..df6b067e72 100644
--- a/crates/ui-egui/src/i18n/zh-hans.tsv
+++ b/crates/ui-egui/src/i18n/zh-hans.tsv
@@ -2316,3 +2316,8 @@ animation effects	Off	关
 	This document is trying to open a local file:	此文档正尝试打开本地文件：
 	Move tag earlier	将标签前移
 	Move tag later	将标签后移
+	Attach a file…	附加文件…
+	Delete attachment	删除附件
+	Attaching files is not available on the web yet	网页版尚不支持附加文件
+	Attach {name}	附加 {name}
+	Delete attachment {key}	删除附件 {key}
diff --git a/crates/ui-egui/src/i18n/zh-hant.tsv b/crates/ui-egui/src/i18n/zh-hant.tsv
index da45921c21..db8ebd1569 100644
--- a/crates/ui-egui/src/i18n/zh-hant.tsv
+++ b/crates/ui-egui/src/i18n/zh-hant.tsv
@@ -2226,3 +2226,8 @@ animation effects	Off	關
 	This document is trying to open a local file:	此文件正嘗試開啟本機檔案：
 	Move tag earlier	將標記前移
 	Move tag later	將標記後移
+	Attach a file…	附加檔案…
+	Delete attachment	刪除附件
+	Attaching files is not available on the web yet	網頁版尚不支援附加檔案
+	Attach {name}	附加 {name}
+	Delete attachment {key}	刪除附件 {key}
diff --git a/crates/ui-egui/src/lib.rs b/crates/ui-egui/src/lib.rs
index ea3da00957..9e952b1c33 100644
--- a/crates/ui-egui/src/lib.rs
+++ b/crates/ui-egui/src/lib.rs
@@ -1440,6 +1440,38 @@ impl PdfCraftApp {
     }
 
     /// Save an attachment to disk, or open a PDF attachment in a new tab.
+    /// Edit ▸ Attach a file…: choose a file, then attach it to the active document and show
+    /// the Attachments panel with it.
+    pub fn attach_file_dialog(&mut self) {
+        if self.active_ids().is_none() {
+            return;
+        }
+        #[cfg(not(target_arch = "wasm32"))]
+        {
+            let dialog = rfd::AsyncFileDialog::new().set_title(tl!("Attach a file").to_string());
+            self.ask_one(pickers::Ask::File(dialog), None, |app, path| app.attach_file(&path));
+        }
+        #[cfg(target_arch = "wasm32")]
+        self.notify_tr("Attaching files is not available on the web yet");
+    }
+
+    /// Attach the file at `path` to the active document (document level: the Attachments
+    /// panel, not a paper-clip comment on a page).
+    pub fn attach_file(&mut self, path: &std::path::Path) {
+        let name = path.file_name().map(|n| n.to_string_lossy().into_owned()).unwrap_or_default();
+        let bytes = match std::fs::read(path) {
+            Ok(b) => b,
+            Err(e) => {
+                self.notify_fmt("Couldn't read {name}: {e}", &[("name", &name), ("e", &e.to_string())]);
+                return;
+            }
+        };
+        let mime = pdfcraft_engine::mime_for_name(&name).map(str::to_string);
+        if self.apply_edit(pdfcraft_engine::Edit::AddAttachment { name, bytes, description: None, mime }) {
+            self.choose_right_panel(Some(RightPanel::Attachments));
+        }
+    }
+
     pub fn attachment_action(&mut self, doc: DocId, index: usize, open: bool) {
         let Some(d) = self.session.get(doc) else { return };
         let Some(att) = d.info.attachments.get(index).cloned() else { return };
diff --git a/crates/ui-egui/src/panels.rs b/crates/ui-egui/src/panels.rs
index bdd625804d..66d8fa07a4 100644
--- a/crates/ui-egui/src/panels.rs
+++ b/crates/ui-egui/src/panels.rs
@@ -680,6 +680,14 @@ pub fn right_panel(app: &mut PdfCraftApp, ui: &mut egui::Ui) {
                     RightPanel::Search => crate::search_ui::panel(ui, &t, view, info.pages.len()),
                     RightPanel::Compare => compare_action = crate::compare_ui::panel(ui, &t, compare, id),
                     RightPanel::Attachments => {
+                        let attachable = doc.allows_modification() && doc.read_only_reason.is_none();
+                        if attachable {
+                            egui::Frame::NONE.inner_margin(egui::Margin::symmetric(4, 6)).show(ui, |ui| {
+                                if ui.add(egui::Button::new(tl!("Attach a file…"))).clicked() {
+                                    panel_command = Some("edit.attach");
+                                }
+                            });
+                        }
                         if info.attachments.is_empty() {
                             empty(ui, &t, "paperclip", "This document has no attachments.");
                         }
@@ -712,6 +720,12 @@ pub fn right_panel(app: &mut PdfCraftApp, ui: &mut egui::Ui) {
                                         {
                                             attachment_action = Some((ai, true));
                                         }
+                                        if let pdfcraft_render::AttachmentSource::Document { key } = &a.source
+                                            && attachable
+                                            && icons::button(ui, "trash-2", 28.0, false, tl!("Delete attachment")).clicked()
+                                        {
+                                            panel_edit = Some(pdfcraft_engine::Edit::DeleteAttachment { key: key.clone() });
+                                        }
                                     });
                                 });
                             });
diff --git a/parity/acrobat-features.toml b/parity/acrobat-features.toml
index 8f4194b932..e3d02b6718 100644
--- a/parity/acrobat-features.toml
+++ b/parity/acrobat-features.toml
@@ -3325,11 +3325,11 @@ title = "Add file attachments"
 area = "D"
 tier = "P2"
 milestone = "M12"
-status = "planned"
-commands = []
-tools = []
-evidence = []
-notes = ""
+status = "shipped"
+commands = ["edit.attach"]
+tools = ["attachment_add"]
+evidence = ["crates/organize/src/tests.rs::attachments_are_added_listed_and_deleted", "crates/organize/src/tests.rs::attachments_added_in_the_app_survive_combine_and_more_can_be_attached", "crates/automation/tests/automation.rs::attaching_and_deleting_files_through_the_tools"]
+notes = "Edit ▸ Attach a file… (also the Attach a file… button in the Attachments panel and the Edit a PDF list): the file goes into /Names /EmbeddedFiles as a Filespec with a Flate-compressed EmbeddedFile stream (/Size, /ModDate, /Subtype from the extension); a name already taken gets \"
 
 [[feature]]
 id = "organize.attachments-delete"
@@ -3337,11 +3337,11 @@ title = "Delete attachments"
 area = "D"
 tier = "P2"
 milestone = "M12"
-status = "planned"
+status = "shipped"
 commands = []
-tools = []
-evidence = []
-notes = ""
+tools = ["attachment_delete"]
+evidence = ["crates/organize/src/tests.rs::attachments_are_added_listed_and_deleted", "crates/organize/src/tests.rs::attachments_added_in_the_app_survive_combine_and_more_can_be_attached", "crates/automation/tests/automation.rs::attaching_and_deleting_files_through_the_tools"]
+notes = "The trash button on a document-level row of the Attachments panel; the last one removed takes the /EmbeddedFiles tree with it. Undoable. A paper-clip comment is deleted as a comment."
 
 [[feature]]
 id = "organize.attachments-description"