diff --git a/rslib/src/import_export/package/apkg/import.rs b/rslib/src/import_export/package/apkg/import.rs
new file mode 100644
index 000000000..e4a07ef85
--- /dev/null
+++ b/rslib/src/import_export/package/apkg/import.rs
@@ -0,0 +1,322 @@
+// Copyright: Ankitects Pty Ltd and contributors
+// License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
+
+use std::{
+    collections::{HashMap, HashSet},
+    fs::{self, File},
+    io::{self, Write},
+    mem,
+    path::{Path, PathBuf},
+    sync::Arc,
+};
+
+use sha1::Sha1;
+use tempfile::NamedTempFile;
+use zip::ZipArchive;
+
+use crate::{
+    collection::CollectionBuilder,
+    import_export::{
+        gather::ExchangeData,
+        package::{colpkg::import::extract_media_entries, Meta},
+    },
+    io::{atomic_rename, tempfile_in_parent_of},
+    prelude::*,
+    text::replace_media_refs,
+};
+
+#[derive(Debug)]
+struct Context {
+    archive: ZipArchive<File>,
+    guid_map: HashMap<String, NoteMeta>,
+    remapped_notetypes: HashMap<NotetypeId, NotetypeId>,
+    existing_notes: HashSet<NoteId>,
+    existing_notetypes: HashSet<NotetypeId>,
+    data: ExchangeData,
+    usn: Usn,
+    media_map: HashMap<String, String>,
+    target_media_folder: PathBuf,
+    conflicting_notes: HashSet<String>,
+}
+
+#[derive(Debug, Clone, Copy)]
+pub(crate) struct NoteMeta {
+    id: NoteId,
+    mtime: TimestampSecs,
+    notetype_id: NotetypeId,
+}
+
+impl NoteMeta {
+    pub(crate) fn new(id: NoteId, mtime: TimestampSecs, notetype_id: NotetypeId) -> Self {
+        Self {
+            id,
+            mtime,
+            notetype_id,
+        }
+    }
+
+    fn from_note(note: &Note) -> Self {
+        Self::new(note.id, note.mtime, note.notetype_id)
+    }
+}
+
+impl Collection {
+    pub fn import_apkg(
+        &mut self,
+        path: &str,
+        search: impl TryIntoSearch,
+        with_scheduling: bool,
+    ) -> Result<()> {
+        let file = File::open(path)?;
+        let archive = ZipArchive::new(file)?;
+
+        let mut ctx = Context::new(archive, self, search, with_scheduling)?;
+        ctx.prepare_notetypes(self)?;
+        ctx.prepare_notes()?;
+
+        self.insert_data(&ctx.data)
+    }
+}
+
+fn build_media_map(archive: &mut ZipArchive<File>) -> Result<HashMap<String, String>> {
+    Ok(extract_media_entries(&Meta::new_legacy(), archive)?
+        .into_iter()
+        .map(|entry| (entry.name, entry.legacy_zip_filename.unwrap().to_string()))
+        .collect())
+}
+
+impl ExchangeData {
+    fn gather_from_archive(
+        archive: &mut ZipArchive<File>,
+        search: impl TryIntoSearch,
+        with_scheduling: bool,
+    ) -> Result<Self> {
+        let mut zip_file = archive.by_name(Meta::new_legacy().collection_filename())?;
+        let mut tempfile = NamedTempFile::new()?;
+        io::copy(&mut zip_file, &mut tempfile)?;
+        let mut col = CollectionBuilder::new(tempfile.path()).build()?;
+
+        let mut data = ExchangeData::default();
+        data.gather_data(&mut col, search, with_scheduling)?;
+
+        Ok(data)
+    }
+}
+
+impl Context {
+    fn new(
+        mut archive: ZipArchive<File>,
+        target_col: &mut Collection,
+        search: impl TryIntoSearch,
+        with_scheduling: bool,
+    ) -> Result<Self> {
+        let data = ExchangeData::gather_from_archive(&mut archive, search, with_scheduling)?;
+        let media_map = build_media_map(&mut archive)?;
+        Ok(Self {
+            archive,
+            data,
+            guid_map: target_col.storage.note_guid_map()?,
+            existing_notes: target_col.storage.get_all_note_ids()?,
+            existing_notetypes: target_col.storage.get_all_notetype_ids()?,
+            media_map,
+            target_media_folder: target_col.media_folder.clone(),
+            usn: target_col.usn()?,
+            conflicting_notes: HashSet::new(),
+            remapped_notetypes: HashMap::new(),
+        })
+    }
+
+    fn prepare_notetypes(&mut self, target_col: &mut Collection) -> Result<()> {
+        for notetype in mem::take(&mut self.data.notetypes) {
+            if let Some(existing) = target_col.get_notetype(notetype.id)? {
+                self.merge_or_remap_notetype(notetype, existing)?;
+            } else {
+                self.add_notetype(notetype);
+            }
+        }
+        Ok(())
+    }
+
+    fn add_notetype(&mut self, mut notetype: Notetype) {
+        self.existing_notetypes.insert(notetype.id);
+        notetype.usn = self.usn;
+        self.data.notetypes.push(notetype);
+    }
+
+    fn merge_or_remap_notetype(
+        &mut self,
+        incoming: Notetype,
+        existing: Arc<Notetype>,
+    ) -> Result<()> {
+        if incoming.schema_hash() == existing.schema_hash() {
+            self.add_notetype_if_newer(incoming, existing);
+        } else {
+            self.add_notetype_with_new_id(incoming)?;
+        }
+        Ok(())
+    }
+
+    fn add_notetype_with_new_id(&mut self, mut notetype: Notetype) -> Result<()> {
+        let new_id = self.next_available_notetype_id();
+        self.remapped_notetypes.insert(notetype.id, new_id);
+        notetype.id = new_id;
+        self.add_notetype(notetype);
+        Ok(())
+    }
+
+    fn next_available_notetype_id(&self) -> NotetypeId {
+        let mut next_id = NotetypeId(TimestampMillis::now().0);
+        while self.existing_notetypes.contains(&next_id) {
+            next_id.0 += 1;
+        }
+        next_id
+    }
+
+    fn add_notetype_if_newer(&mut self, incoming: Notetype, existing: Arc<Notetype>) {
+        if incoming.mtime_secs > existing.mtime_secs {
+            self.add_notetype(incoming);
+        }
+    }
+
+    fn prepare_notes(&mut self) -> Result<()> {
+        for mut note in mem::take(&mut self.data.notes) {
+            if let Some(notetype_id) = self.remapped_notetypes.get(&note.notetype_id) {
+                if self.guid_map.contains_key(&note.guid) {
+                    todo!("ignore");
+                } else {
+                    note.notetype_id = *notetype_id;
+                    self.prepare_new_note(note)?;
+                }
+            } else if let Some(&meta) = self.guid_map.get(&note.guid) {
+                self.prepare_existing_note(note, meta)?;
+            } else {
+                self.prepare_new_note(note)?;
+            }
+        }
+        Ok(())
+    }
+
+    fn add_prepared_note(&mut self, mut note: Note) -> Result<()> {
+        self.munge_media(&mut note)?;
+        note.usn = self.usn;
+        self.data.notes.push(note);
+        Ok(())
+    }
+
+    fn prepare_new_note(&mut self, mut note: Note) -> Result<()> {
+        self.to_next_available_note_id(&mut note.id);
+        self.existing_notes.insert(note.id);
+        self.guid_map
+            .insert(note.guid.clone(), NoteMeta::from_note(&note));
+        self.add_prepared_note(note)
+        // TODO: Log add
+    }
+
+    fn prepare_existing_note(&mut self, mut note: Note, meta: NoteMeta) -> Result<()> {
+        if meta.mtime < note.mtime {
+            if meta.notetype_id == note.notetype_id {
+                note.id = meta.id;
+                self.add_prepared_note(note)?;
+                // TODO: Log update
+            } else {
+                self.conflicting_notes.insert(note.guid);
+                // TODO: Log ignore
+            }
+        } else {
+            // TODO: Log duplicate
+        }
+        Ok(())
+    }
+
+    fn munge_media(&mut self, note: &mut Note) -> Result<()> {
+        let notetype_id = note.notetype_id;
+        for field in note.fields_mut() {
+            if let Some(new_field) = self.replace_media_refs_fallible(field, notetype_id)? {
+                *field = new_field;
+            };
+        }
+        Ok(())
+    }
+
+    fn replace_media_refs_fallible(
+        &mut self,
+        field: &mut String,
+        notetype_id: NotetypeId,
+    ) -> Result<Option<String>> {
+        let mut res = Ok(());
+        let out = replace_media_refs(field, |name| {
+            if res.is_err() {
+                None
+            } else {
+                self.merge_media_maybe_renaming(name, notetype_id)
+                    .unwrap_or_else(|err| {
+                        res = Err(err);
+                        None
+                    })
+            }
+        });
+        res.map(|_| out)
+    }
+
+    fn merge_media_maybe_renaming(
+        &mut self,
+        name: &str,
+        notetype: NotetypeId,
+    ) -> Result<Option<String>> {
+        Ok(if let Some(zip_name) = self.media_map.get(name) {
+            let alternate_name = alternate_media_name(name, notetype);
+            let alternate_path = self.target_media_folder.join(&alternate_name);
+            if alternate_path.exists() {
+                Some(alternate_name)
+            } else {
+                let mut data = Vec::new();
+                io::copy(&mut self.archive.by_name(zip_name)?, &mut data)?;
+                let target_path = self.target_media_folder.join(name);
+                if !target_path.exists() {
+                    write_data_atomically(&data, &target_path)?;
+                    None
+                } else if data == fs::read(target_path)? {
+                    None
+                } else {
+                    write_data_atomically(&data, &alternate_path)?;
+                    Some(alternate_name)
+                }
+            }
+        } else {
+            None
+        })
+    }
+
+    fn to_next_available_note_id(&self, note_id: &mut NoteId) {
+        while self.existing_notes.contains(note_id) {
+            note_id.0 += 999;
+        }
+    }
+}
+
+fn write_data_atomically(data: &[u8], path: &Path) -> Result<()> {
+    let mut tempfile = tempfile_in_parent_of(path)?;
+    tempfile.write_all(data)?;
+    atomic_rename(tempfile, path, false)
+}
+
+fn alternate_media_name(name: &str, notetype_id: NotetypeId) -> String {
+    let (stem, dot, extension) = name
+        .rsplit_once('.')
+        .map(|(stem, ext)| (stem, ".", ext))
+        .unwrap_or((name, "", ""));
+    format!("{stem}_{notetype_id}{dot}{extension}")
+}
+
+impl Notetype {
+    fn schema_hash(&self) -> [u8; 20] {
+        let mut hasher = Sha1::new();
+        for field in &self.fields {
+            hasher.update(field.name.as_bytes());
+        }
+        for template in &self.templates {
+            hasher.update(template.name.as_bytes());
+        }
+        hasher.digest().bytes()
+    }
+}
diff --git a/rslib/src/import_export/package/apkg/mod.rs b/rslib/src/import_export/package/apkg/mod.rs
index e6d0a437e..f66c826e8 100644
--- a/rslib/src/import_export/package/apkg/mod.rs
+++ b/rslib/src/import_export/package/apkg/mod.rs
@@ -2,3 +2,6 @@
 // License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
 mod export;
+mod import;
+
+pub(crate) use import::NoteMeta;
diff --git a/rslib/src/import_export/package/colpkg/import.rs b/rslib/src/import_export/package/colpkg/import.rs
index 544db04bd..95b5383e7 100644
--- a/rslib/src/import_export/package/colpkg/import.rs
+++ b/rslib/src/import_export/package/colpkg/import.rs
@@ -187,7 +187,10 @@ fn maybe_normalizing(name: &str, strict: bool) -> Result<Cow<str>> {
     }
 }
 
-fn extract_media_entries(meta: &Meta, archive: &mut ZipArchive<File>) -> Result<Vec<MediaEntry>> {
+pub(crate) fn extract_media_entries(
+    meta: &Meta,
+    archive: &mut ZipArchive<File>,
+) -> Result<Vec<MediaEntry>> {
     let mut file = archive.by_name("media")?;
     let mut buf = Vec::new();
     if meta.zstd_compressed() {
diff --git a/rslib/src/import_export/package/mod.rs b/rslib/src/import_export/package/mod.rs
index c44e81891..9ce6c4d33 100644
--- a/rslib/src/import_export/package/mod.rs
+++ b/rslib/src/import_export/package/mod.rs
@@ -5,6 +5,7 @@ mod apkg;
 mod colpkg;
 mod meta;
 
+pub(crate) use apkg::NoteMeta;
 pub(crate) use colpkg::export::export_colpkg_from_data;
 pub use colpkg::import::import_colpkg;
 pub(self) use meta::{Meta, Version};
diff --git a/rslib/src/storage/note/mod.rs b/rslib/src/storage/note/mod.rs
index 1322eec71..bb5c949eb 100644
--- a/rslib/src/storage/note/mod.rs
+++ b/rslib/src/storage/note/mod.rs
@@ -1,12 +1,13 @@
 // Copyright: Ankitects Pty Ltd and contributors
 // License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
-use std::collections::HashSet;
+use std::collections::{HashMap, HashSet};
 
 use rusqlite::{params, Row};
 
 use crate::{
     error::Result,
+    import_export::package::NoteMeta,
     notes::{Note, NoteId, NoteTags},
     notetype::NotetypeId,
     tags::{join_tags, split_tags},
@@ -41,6 +42,13 @@ impl super::SqliteStorage {
             .transpose()
     }
 
+    pub fn get_all_note_ids(&self) -> Result<HashSet<NoteId>> {
+        self.db
+            .prepare("SELECT id FROM notes")?
+            .query_and_then([], |row| Ok(row.get(0)?))?
+            .collect()
+    }
+
     /// If fields have been modified, caller must call note.prepare_for_update() prior to calling this.
     pub(crate) fn update_note(&self, note: &Note) -> Result<()> {
         assert!(note.id.0 != 0);
@@ -269,6 +277,13 @@ impl super::SqliteStorage {
 
         Ok(())
     }
+
+    pub(crate) fn note_guid_map(&mut self) -> Result<HashMap<String, NoteMeta>> {
+        self.db
+            .prepare("SELECT guid, id, mod, mid FROM notes")?
+            .query_and_then([], row_to_note_meta)?
+            .collect()
+    }
 }
 
 fn row_to_note(row: &Row) -> Result<Note> {
@@ -295,3 +310,10 @@ fn row_to_note_tags(row: &Row) -> Result<NoteTags> {
         tags: row.get(3)?,
     })
 }
+
+fn row_to_note_meta(row: &Row) -> Result<(String, NoteMeta)> {
+    Ok((
+        row.get(0)?,
+        NoteMeta::new(row.get(1)?, row.get(2)?, row.get(3)?),
+    ))
+}
diff --git a/rslib/src/storage/notetype/mod.rs b/rslib/src/storage/notetype/mod.rs
index 3ada340a8..3b5237d37 100644
--- a/rslib/src/storage/notetype/mod.rs
+++ b/rslib/src/storage/notetype/mod.rs
@@ -123,6 +123,13 @@ impl SqliteStorage {
             .collect()
     }
 
+    pub fn get_all_notetype_ids(&self) -> Result<HashSet<NotetypeId>> {
+        self.db
+            .prepare("SELECT id FROM notetypes")?
+            .query_and_then([], |row| Ok(row.get(0)?))?
+            .collect()
+    }
+
     /// Returns list of (id, name, use_count)
     pub fn get_notetype_use_counts(&self) -> Result<Vec<(NotetypeId, String, u32)>> {
         self.db
diff --git a/rslib/src/text.rs b/rslib/src/text.rs
index f4496837c..6c43f6008 100644
--- a/rslib/src/text.rs
+++ b/rslib/src/text.rs
@@ -246,6 +246,35 @@ pub(crate) fn extract_media_refs(text: &str) -> Vec<MediaRef> {
     out
 }
 
+/// Calls `replacer` for every media reference in `text`, and optionally
+/// replaces it with something else. [None] if no reference was found.
+pub(crate) fn replace_media_refs(
+    text: &str,
+    mut replacer: impl FnMut(&str) -> Option<String>,
+) -> Option<String> {
+    let mut rep = |caps: &Captures| {
+        let whole_match = caps.get(0).unwrap().as_str();
+        let old_name = caps.iter().skip(1).find_map(|g| g).unwrap().as_str();
+        if let Some(new_name) = replacer(old_name) {
+            whole_match.replace(old_name, &new_name)
+        } else {
+            whole_match.to_owned()
+        }
+    };
+
+    let mut out = Cow::from(text);
+    if let Cow::Owned(s) = HTML_MEDIA_TAGS.replace_all(&out, &mut rep) {
+        out = s.into();
+    }
+    if let Cow::Owned(s) = AV_TAGS.replace_all(&out, &mut rep) {
+        out = s.into();
+    }
+    match out {
+        Cow::Owned(s) => Some(s),
+        Cow::Borrowed(_) => None,
+    }
+}
+
 pub(crate) fn extract_underscored_css_imports(text: &str) -> Vec<&str> {
     UNDERSCORED_CSS_IMPORTS
         .captures_iter(text)