diff --git a/datman/src/commands/pushpull.rs b/datman/src/commands/pushpull.rs
index 5a10811..8624a4d 100644
--- a/datman/src/commands/pushpull.rs
+++ b/datman/src/commands/pushpull.rs
@@ -3,8 +3,11 @@
 use anyhow::{ensure, Context};
 use std::collections::{BTreeMap, BTreeSet};
 use std::io::{Read, Write};
-use yama::definitions::{ChunkId, PointerData};
-use yama::pile::{Pile, PipelineDescription, RawPile};
+use yama::chunking::RecursiveUnchunker;
+use yama::commands::{fully_load_pointer, retrieve_tree_node};
+use yama::definitions::{ChunkId, PointerData, RecursiveChunkRef, TreeNode};
+use yama::pile::{Keyspace, Pile, PipelineDescription, RawPile};
+use yama::progress::ProgressTracker;
 use yama::remote::{read_message, write_message};
 
 pub fn offer_pointers<W: Write, RP: RawPile>(
@@ -78,11 +81,59 @@ pub fn negotiate_bypassed_pile<R: Read, W: Write>(
     Ok(())
 }
 
+fn collect_chunk_ids(
+    pile: &Pile<Box<dyn RawPile>>,
+    root: &TreeNode,
+    chunk_ids: &mut BTreeSet<ChunkId>,
+) -> anyhow::Result<()> {
+    root.visit(
+        &mut |tree_node, _| {
+            match tree_node {
+                TreeNode::NormalFile { content, .. } => {
+                    collect_chunk_ids_from_chunkref(pile, content, chunk_ids)?;
+                }
+                _ => {}
+            }
+            Ok(())
+        },
+        "".to_owned(),
+    )?;
+    Ok(())
+}
+
+fn collect_chunk_ids_from_chunkref(
+    pile: &Pile<Box<dyn RawPile>>,
+    chunk_ref: &RecursiveChunkRef,
+    collection: &mut BTreeSet<ChunkId>,
+) -> anyhow::Result<()> {
+    if chunk_ref.depth == 0 {
+        collection.insert(condense_chunk_id(chunk_ref.chunk_id));
+    } else {
+        let shallower_chunk_ref = RecursiveChunkRef {
+            chunk_id: chunk_ref.chunk_id,
+            depth: chunk_ref.depth - 1,
+        };
+        let mut unchunker = RecursiveUnchunker::new(pile, shallower_chunk_ref);
+        let mut next_chunk_id: ChunkId = Default::default();
+        loop {
+            let read = unchunker.read(&mut next_chunk_id[..])?;
+            if read == 0 {
+                break;
+            } else if read < next_chunk_id.len() {
+                unchunker.read_exact(&mut next_chunk_id[read..])?;
+            }
+            collection.insert(condense_chunk_id(next_chunk_id));
+        }
+    }
+    Ok(())
+}
+
 pub fn offering_side<R: Read, W: Write>(
     pile: &Pile<Box<dyn RawPile>>,
     bypass_pile: Box<dyn RawPile>,
     reader: &mut R,
     writer: &mut W,
+    mut progress: Box<dyn ProgressTracker>,
 ) -> anyhow::Result<()> {
     // First 'negotiate' (for now: assert) a pile bypass.
     // This lets us avoid decompressing things before recompressing them at the other end,
@@ -92,26 +143,39 @@ pub fn offering_side<R: Read, W: Write>(
     let offered_pointers = offer_pointers(pile, writer)?;
     let wanted_pointers = read_message::<_, Vec<String>>(reader)?;
 
-    for pointer in &wanted_pointers {
-        ensure!(
-            offered_pointers.contains_key(pointer),
-            "Requested pointer {:?} not offered",
-            pointer
-        );
-    }
+    let mut chunks_to_offer: BTreeSet<ChunkId> = BTreeSet::new();
 
-    let chunks_to_offer: BTreeSet<ChunkId> = todo!();
+    for pointer_name in &wanted_pointers {
+        let pointer_data = offered_pointers
+            .get(pointer_name)
+            .with_context(|| format!("Requested pointer {:?} was not offered", pointer_name))?;
+
+        collect_chunk_ids_from_chunkref(pile, &pointer_data.chunk_ref, &mut chunks_to_offer)?;
+
+        let root_node = retrieve_tree_node(pile, pointer_data.chunk_ref.clone())?;
+        collect_chunk_ids(pile, &root_node.node, &mut chunks_to_offer)?;
+    }
 
     write_message(writer, &chunks_to_offer)?;
 
     let chunks_to_skip: BTreeSet<ChunkId> = read_message(reader)?;
-    let chunks_to_send: Vec<ChunkId> = chunks_to_offer.difference(&chunks_to_skip).collect();
+    let chunks_to_send: Vec<ChunkId> = chunks_to_offer
+        .difference(&chunks_to_skip)
+        .cloned()
+        .collect();
 
     drop(chunks_to_offer);
     drop(chunks_to_skip);
 
+    progress.set_max_size(chunks_to_send.len() as u64);
+    progress.set_current(0);
     for chunk_id in chunks_to_send {
-        todo!();
+        let chunk_data = bypass_pile
+            .read(Keyspace::Chunk, &chunk_id)?
+            .context("Chunk vanished")?;
+
+        write_message(writer, &Some((chunk_id, chunk_data)))?;
+        progress.inc_progress(1);
     }
 
     Ok(())