diff --git a/poc-memory/schema/memory.capnp b/poc-memory/schema/memory.capnp
index 4b71faa..87be4c2 100644
--- a/poc-memory/schema/memory.capnp
+++ b/poc-memory/schema/memory.capnp
@@ -122,3 +122,18 @@ struct AgentVisit {
 struct AgentVisitLog {
   visits @0 :List(AgentVisit);
 }
+
+# Transcript mining progress — separate append-only log.
+# Tracks which segments of which transcripts have been processed,
+# by which agent, so we never re-mine the same content.
+
+struct TranscriptSegment {
+  transcriptId  @0 :Text;     # session UUID (filename stem)
+  segmentIndex  @1 :UInt32;   # compaction segment index within transcript
+  agent         @2 :Text;     # "observation", "experience", "fact"
+  timestamp     @3 :Int64;    # unix epoch seconds when mining completed
+}
+
+struct TranscriptProgressLog {
+  segments @0 :List(TranscriptSegment);
+}
diff --git a/poc-memory/src/main.rs b/poc-memory/src/main.rs
index bf479d9..d5b5157 100644
--- a/poc-memory/src/main.rs
+++ b/poc-memory/src/main.rs
@@ -643,6 +643,9 @@ enum AdminCmd {
         /// Date (default: today)
         date: Option<String>,
     },
+    /// Migrate transcript stub nodes to progress log
+    #[command(name = "migrate-transcript-progress")]
+    MigrateTranscriptProgress,
 }
 
 #[derive(Subcommand)]
@@ -817,6 +820,12 @@ fn main() {
             AdminCmd::Params => cli::misc::cmd_params(),
             AdminCmd::LookupBump { keys } => cli::node::cmd_lookup_bump(&keys),
             AdminCmd::Lookups { date } => cli::node::cmd_lookups(date.as_deref()),
+            AdminCmd::MigrateTranscriptProgress => (|| -> Result<(), String> {
+                let mut store = store::Store::load()?;
+                let count = store.migrate_transcript_progress()?;
+                println!("Migrated {} transcript segment markers", count);
+                Ok(())
+            })()
         },
     };
 
diff --git a/poc-memory/src/store/persist.rs b/poc-memory/src/store/persist.rs
index ca608c7..17895fe 100644
--- a/poc-memory/src/store/persist.rs
+++ b/poc-memory/src/store/persist.rs
@@ -35,6 +35,10 @@ impl Store {
                 if visits_p.exists() {
                     store.replay_visits(&visits_p).ok();
                 }
+                let tp_p = transcript_progress_path();
+                if tp_p.exists() {
+                    store.replay_transcript_progress(&tp_p).ok();
+                }
                 return Ok(store);
             },
             Ok(None) => {},
@@ -87,6 +91,10 @@ impl Store {
         if visits_p.exists() {
             store.replay_visits(&visits_p)?;
         }
+        let tp_p = transcript_progress_path();
+        if tp_p.exists() {
+            store.replay_transcript_progress(&tp_p)?;
+        }
 
         // Record log sizes after replay — this is the state we reflect
         store.loaded_nodes_size = fs::metadata(&nodes_p).map(|m| m.len()).unwrap_or(0);
@@ -119,6 +127,10 @@ impl Store {
         if visits_p.exists() {
             store.replay_visits(&visits_p)?;
         }
+        let tp_p = transcript_progress_path();
+        if tp_p.exists() {
+            store.replay_transcript_progress(&tp_p)?;
+        }
         Ok(store)
     }
 
@@ -424,6 +436,157 @@ impl Store {
         Ok(())
     }
 
+    /// Append transcript segment progress records.
+    pub fn append_transcript_progress(&mut self, segments: &[TranscriptSegment]) -> Result<(), String> {
+        if segments.is_empty() { return Ok(()); }
+
+        let mut msg = message::Builder::new_default();
+        {
+            let log = msg.init_root::<memory_capnp::transcript_progress_log::Builder>();
+            let mut list = log.init_segments(segments.len() as u32);
+            for (i, seg) in segments.iter().enumerate() {
+                seg.to_capnp(list.reborrow().get(i as u32));
+            }
+        }
+        let mut buf = Vec::new();
+        serialize::write_message(&mut buf, &msg)
+            .map_err(|e| format!("serialize transcript progress: {}", e))?;
+
+        let path = transcript_progress_path();
+        let file = fs::OpenOptions::new()
+            .create(true).append(true).open(&path)
+            .map_err(|e| format!("open {}: {}", path.display(), e))?;
+        use std::io::Write;
+        (&file).write_all(&buf)
+            .map_err(|e| format!("write transcript progress: {}", e))?;
+
+        // Update in-memory index
+        for seg in segments {
+            self.transcript_progress
+                .entry((seg.transcript_id.clone(), seg.segment_index))
+                .or_default()
+                .insert(seg.agent.clone());
+        }
+
+        Ok(())
+    }
+
+    /// Replay transcript progress log to rebuild in-memory index.
+    fn replay_transcript_progress(&mut self, path: &Path) -> Result<(), String> {
+        let file = fs::File::open(path)
+            .map_err(|e| format!("open {}: {}", path.display(), e))?;
+        let mut reader = BufReader::new(file);
+
+        while reader.stream_position().map_err(|e| e.to_string())?
+              < fs::metadata(path).map_err(|e| e.to_string())?.len()
+        {
+            let msg = match serialize::read_message(&mut reader, Default::default()) {
+                Ok(m) => m,
+                Err(_) => break,
+            };
+            let log = msg.get_root::<memory_capnp::transcript_progress_log::Reader>()
+                .map_err(|e| format!("read transcript progress: {}", e))?;
+
+            for seg in log.get_segments().map_err(|e| e.to_string())? {
+                let id = seg.get_transcript_id().ok()
+                    .and_then(|t| t.to_str().ok())
+                    .unwrap_or("")
+                    .to_string();
+                let agent = seg.get_agent().ok()
+                    .and_then(|t| t.to_str().ok())
+                    .unwrap_or("")
+                    .to_string();
+                let idx = seg.get_segment_index();
+
+                if !id.is_empty() && !agent.is_empty() {
+                    self.transcript_progress
+                        .entry((id, idx))
+                        .or_default()
+                        .insert(agent);
+                }
+            }
+        }
+        Ok(())
+    }
+
+    /// Check if a transcript segment has been processed by a given agent.
+    pub fn is_segment_mined(&self, transcript_id: &str, segment_index: u32, agent: &str) -> bool {
+        self.transcript_progress
+            .get(&(transcript_id.to_string(), segment_index))
+            .map_or(false, |agents| agents.contains(agent))
+    }
+
+    /// Mark a transcript segment as successfully processed.
+    pub fn mark_segment_mined(&mut self, transcript_id: &str, segment_index: u32, agent: &str) -> Result<(), String> {
+        let seg = new_transcript_segment(transcript_id, segment_index, agent);
+        self.append_transcript_progress(&[seg])
+    }
+
+    /// Migrate old stub-node transcript markers into the new progress log.
+    /// Reads _observed-transcripts-f-*, _mined-transcripts#f-*, and _facts-* keys,
+    /// extracts transcript_id and segment_index, writes to transcript-progress.capnp,
+    /// then deletes the stub nodes.
+    pub fn migrate_transcript_progress(&mut self) -> Result<usize, String> {
+        let mut segments = Vec::new();
+
+        for (key, _node) in &self.nodes {
+            // _observed-transcripts-f-{UUID}.{segment}
+            if let Some(rest) = key.strip_prefix("_observed-transcripts-f-") {
+                if let Some((uuid, seg_str)) = rest.rsplit_once('.') {
+                    if let Ok(seg) = seg_str.parse::<u32>() {
+                        segments.push(new_transcript_segment(uuid, seg, "observation"));
+                    }
+                }
+            }
+            // _mined-transcripts#f-{UUID}.{segment}
+            else if let Some(rest) = key.strip_prefix("_mined-transcripts#f-") {
+                if let Some((uuid, seg_str)) = rest.rsplit_once('.') {
+                    if let Ok(seg) = seg_str.parse::<u32>() {
+                        segments.push(new_transcript_segment(uuid, seg, "experience"));
+                    }
+                }
+            }
+            // _mined-transcripts-f-{UUID}.{segment}
+            else if let Some(rest) = key.strip_prefix("_mined-transcripts-f-") {
+                if let Some((uuid, seg_str)) = rest.rsplit_once('.') {
+                    if let Ok(seg) = seg_str.parse::<u32>() {
+                        segments.push(new_transcript_segment(uuid, seg, "experience"));
+                    }
+                }
+            }
+            // _facts-{UUID}  (whole-file, segment 0)
+            else if let Some(uuid) = key.strip_prefix("_facts-") {
+                if !uuid.contains('-') || uuid.len() < 30 { continue; } // skip non-UUID
+                segments.push(new_transcript_segment(uuid, 0, "fact"));
+            }
+        }
+
+        let count = segments.len();
+        if count > 0 {
+            self.append_transcript_progress(&segments)?;
+        }
+
+        // Soft-delete the old stub nodes
+        let keys_to_delete: Vec<String> = self.nodes.keys()
+            .filter(|k| k.starts_with("_observed-transcripts-")
+                || k.starts_with("_mined-transcripts")
+                || (k.starts_with("_facts-") && !k.contains("fact_mine")))
+            .cloned()
+            .collect();
+
+        for key in &keys_to_delete {
+            if let Some(node) = self.nodes.get_mut(key) {
+                node.deleted = true;
+            }
+        }
+
+        if !keys_to_delete.is_empty() {
+            self.save()?;
+        }
+
+        Ok(count)
+    }
+
     /// Record visits for a batch of node keys from a successful agent run.
     pub fn record_agent_visits(&mut self, node_keys: &[String], agent: &str) -> Result<(), String> {
         let visits: Vec<AgentVisit> = node_keys.iter()
diff --git a/poc-memory/src/store/types.rs b/poc-memory/src/store/types.rs
index 2d95a61..6fb4a37 100644
--- a/poc-memory/src/store/types.rs
+++ b/poc-memory/src/store/types.rs
@@ -8,7 +8,7 @@ use crate::memory_capnp;
 use serde::{Deserialize, Serialize};
 use uuid::Uuid;
 
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 use std::fs;
 use std::os::unix::io::AsRawFd;
 use std::path::PathBuf;
@@ -442,6 +442,9 @@ pub struct Store {
     /// Agent visit tracking: node_key → (agent_type → last_visit_epoch)
     #[serde(default)]
     pub visits: VisitIndex,
+    /// Transcript mining progress: (transcript_id, segment_index) → set of agents that processed it
+    #[serde(default)]
+    pub transcript_progress: HashMap<(String, u32), HashSet<String>>,
     /// Log sizes at load time — used by save() to write correct staleness header.
     /// If another writer appended since we loaded, our cache will be marked stale
     /// (recorded size < actual size), forcing the next reader to replay the log.
@@ -560,6 +563,36 @@ pub fn new_visit(node_uuid: [u8; 16], node_key: &str, agent: &str, outcome: &str
 
 pub(crate) fn visits_path() -> PathBuf { memory_dir().join("visits.capnp") }
 
+/// Transcript mining progress — tracks which segments have been processed
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct TranscriptSegment {
+    pub transcript_id: String,
+    pub segment_index: u32,
+    pub agent: String,
+    pub timestamp: i64,
+}
+
+capnp_message!(TranscriptSegment,
+    reader: memory_capnp::transcript_segment::Reader<'_>,
+    builder: memory_capnp::transcript_segment::Builder<'_>,
+    text: [transcript_id, agent],
+    uuid: [],
+    prim: [segment_index, timestamp],
+    enm:  [],
+    skip: [],
+);
+
+pub fn new_transcript_segment(transcript_id: &str, segment_index: u32, agent: &str) -> TranscriptSegment {
+    TranscriptSegment {
+        transcript_id: transcript_id.to_string(),
+        segment_index,
+        agent: agent.to_string(),
+        timestamp: now_epoch(),
+    }
+}
+
+pub(crate) fn transcript_progress_path() -> PathBuf { memory_dir().join("transcript-progress.capnp") }
+
 /// Create a new relation.
 /// Provenance is set from POC_PROVENANCE env var if present, else "manual".
 pub fn new_relation(