diff --git a/_primitives/_rust/kei-buddy/Cargo.toml b/_primitives/_rust/kei-buddy/Cargo.toml
index 8434ced..992fdf2 100644
--- a/_primitives/_rust/kei-buddy/Cargo.toml
+++ b/_primitives/_rust/kei-buddy/Cargo.toml
@@ -28,6 +28,8 @@ reqwest = { workspace = true }
 anyhow = { workspace = true }
 kei-memory-sqlite = { path = "../kei-memory-sqlite" }
 kei-chat-store = { path = "../kei-chat-store" }
+kei-social-store = { path = "../kei-social-store" }
+kei-sage = { path = "../kei-sage" }
 chrono = { workspace = true }
 
 # serve feature deps
diff --git a/_primitives/_rust/kei-buddy/src/contacts.rs b/_primitives/_rust/kei-buddy/src/contacts.rs
new file mode 100644
index 0000000..01da74c
--- /dev/null
+++ b/_primitives/_rust/kei-buddy/src/contacts.rs
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: Apache-2.0
+//! `Contacts` — async address-book adapter over `kei-social-store`.
+//! Arc<Mutex<Store>> + spawn_blocking pattern (same as chat_log.rs).
+//! Never `await` while holding the std::sync::Mutex guard.
+
+use std::collections::HashSet;
+use std::path::Path;
+use std::sync::{Arc, Mutex};
+
+use kei_social_store::{
+    graph::Pair,
+    interactions::{self, Interaction},
+    people::{self, Person},
+    search::search_people,
+    Store,
+};
+
+use crate::error::BuddyError;
+
+/// Async contact-book backed by `kei-social-store`.
+pub struct Contacts {
+    store: Arc<Mutex<Store>>,
+}
+
+impl Contacts {
+    /// Open a file-backed contact store at `path`.
+    pub fn from_path(path: impl AsRef<Path>) -> Result<Self, BuddyError> {
+        let store = Store::open(path.as_ref())
+            .map_err(|e| BuddyError::Memory(format!("{e}")))?;
+        Ok(Self { store: Arc::new(Mutex::new(store)) })
+    }
+
+    /// Open an in-memory store (useful for tests).
+    pub fn from_memory() -> Result<Self, BuddyError> {
+        let store = Store::open_memory()
+            .map_err(|e| BuddyError::Memory(format!("{e}")))?;
+        Ok(Self { store: Arc::new(Mutex::new(store)) })
+    }
+
+    /// Add a contact; returns the new row id.
+    pub async fn add_contact(&self, p: Person) -> Result<i64, BuddyError> {
+        let store = Arc::clone(&self.store);
+        tokio::task::spawn_blocking(move || {
+            let locked = store.lock().expect("store mutex poisoned");
+            people::add_person(&locked, &p).map_err(|e| BuddyError::Memory(format!("{e}")))
+        })
+        .await
+        .map_err(|e| BuddyError::Memory(format!("spawn_blocking join: {e}")))?
+    }
+
+    /// Retrieve a contact by id; `None` if not found.
+    pub async fn get_contact(&self, id: i64) -> Result<Option<Person>, BuddyError> {
+        let store = Arc::clone(&self.store);
+        tokio::task::spawn_blocking(move || {
+            let locked = store.lock().expect("store mutex poisoned");
+            people::get_person(&locked, id).map_err(|e| BuddyError::Memory(format!("{e}")))
+        })
+        .await
+        .map_err(|e| BuddyError::Memory(format!("spawn_blocking join: {e}")))?
+    }
+
+    /// Full-text search over contacts.
+    pub async fn search_contacts(&self, q: &str, limit: i64) -> Result<Vec<Person>, BuddyError> {
+        let store = Arc::clone(&self.store);
+        let q = q.to_string();
+        tokio::task::spawn_blocking(move || {
+            let locked = store.lock().expect("store mutex poisoned");
+            search_people(&locked, &q, limit).map_err(|e| BuddyError::Memory(format!("{e}")))
+        })
+        .await
+        .map_err(|e| BuddyError::Memory(format!("spawn_blocking join: {e}")))?
+    }
+
+    /// Log a meeting between `person_id` (source) and `target_id` on `channel`.
+    /// Returns the new interaction row id.
+    pub async fn log_meet(
+        &self,
+        person_id: i64,
+        target_id: i64,
+        channel: &str,
+        note: &str,
+    ) -> Result<i64, BuddyError> {
+        let store = Arc::clone(&self.store);
+        let interaction = Interaction {
+            id: 0,
+            person_id,
+            target_id,
+            interaction_type: "meet".to_string(),
+            channel: channel.to_string(),
+            content: note.to_string(),
+            timestamp: 0,
+        };
+        tokio::task::spawn_blocking(move || {
+            let locked = store.lock().expect("store mutex poisoned");
+            interactions::log_interaction(&locked, &interaction)
+                .map_err(|e| BuddyError::Memory(format!("{e}")))
+        })
+        .await
+        .map_err(|e| BuddyError::Memory(format!("spawn_blocking join: {e}")))?
+    }
+
+    /// List all interactions where `person_id` is the source.
+    pub async fn interactions_for(&self, person_id: i64) -> Result<Vec<Interaction>, BuddyError> {
+        let store = Arc::clone(&self.store);
+        tokio::task::spawn_blocking(move || {
+            let locked = store.lock().expect("store mutex poisoned");
+            interactions::interactions_for(&locked, person_id)
+                .map_err(|e| BuddyError::Memory(format!("{e}")))
+        })
+        .await
+        .map_err(|e| BuddyError::Memory(format!("spawn_blocking join: {e}")))?
+    }
+
+    /// Returns the full relationship graph as `Vec<Pair>`.
+    pub async fn relationship_graph(&self) -> Result<Vec<Pair>, BuddyError> {
+        let store = Arc::clone(&self.store);
+        tokio::task::spawn_blocking(move || {
+            let locked = store.lock().expect("store mutex poisoned");
+            kei_social_store::graph::relationship_graph(&locked)
+                .map_err(|e| BuddyError::Memory(format!("{e}")))
+        })
+        .await
+        .map_err(|e| BuddyError::Memory(format!("spawn_blocking join: {e}")))?
+    }
+
+    /// People who interacted with BOTH `person_a` AND `person_b`
+    /// (appear as `target_id` in pairs for both sources).
+    pub async fn common_connections(
+        &self,
+        person_a: i64,
+        person_b: i64,
+    ) -> Result<Vec<i64>, BuddyError> {
+        let pairs = self.relationship_graph().await?;
+        let targets_a: HashSet<i64> = pairs
+            .iter()
+            .filter(|p| p.person_id == person_a)
+            .map(|p| p.target_id)
+            .collect();
+        let targets_b: HashSet<i64> = pairs
+            .iter()
+            .filter(|p| p.person_id == person_b)
+            .map(|p| p.target_id)
+            .collect();
+        Ok(targets_a.intersection(&targets_b).copied().collect())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use kei_social_store::Person;
+
+    fn alice() -> Person { Person { name: "Denis".to_string(), email: "d@test.com".to_string(), ..Default::default() } }
+    fn bob() -> Person { Person { name: "Bob".to_string(), email: "b@test.com".to_string(), ..Default::default() } }
+    fn charlie() -> Person { Person { name: "Charlie".to_string(), email: "c@test.com".to_string(), ..Default::default() } }
+
+    #[tokio::test]
+    async fn add_and_get_contact_roundtrip() {
+        let contacts = Contacts::from_memory().unwrap();
+        let id = contacts.add_contact(alice()).await.unwrap();
+        assert!(id > 0);
+        let found = contacts.get_contact(id).await.unwrap();
+        assert!(found.is_some());
+        assert_eq!(found.unwrap().name, "Denis");
+    }
+
+    #[tokio::test]
+    async fn search_contacts_finds_by_name() {
+        let contacts = Contacts::from_memory().unwrap();
+        contacts.add_contact(alice()).await.unwrap();
+        contacts.add_contact(bob()).await.unwrap();
+        let results = contacts.search_contacts("Denis", 10).await.unwrap();
+        assert!(!results.is_empty());
+        assert!(results.iter().any(|p| p.name == "Denis"));
+    }
+
+    #[tokio::test]
+    async fn log_meet_and_list_interactions() {
+        let contacts = Contacts::from_memory().unwrap();
+        let a = contacts.add_contact(alice()).await.unwrap();
+        let b = contacts.add_contact(bob()).await.unwrap();
+        let iid = contacts.log_meet(a, b, "telegram", "hi").await.unwrap();
+        assert!(iid > 0);
+        let list = contacts.interactions_for(a).await.unwrap();
+        assert!(!list.is_empty());
+        assert_eq!(list[0].channel, "telegram");
+    }
+
+    #[tokio::test]
+    async fn common_connections_finds_shared_target() {
+        let contacts = Contacts::from_memory().unwrap();
+        let a = contacts.add_contact(alice()).await.unwrap();
+        let b = contacts.add_contact(bob()).await.unwrap();
+        let c = contacts.add_contact(charlie()).await.unwrap();
+        contacts.log_meet(a, c, "telegram", "met charlie").await.unwrap();
+        contacts.log_meet(b, c, "telegram", "also met charlie").await.unwrap();
+        let common = contacts.common_connections(a, b).await.unwrap();
+        assert!(common.contains(&c));
+    }
+}
diff --git a/_primitives/_rust/kei-buddy/src/lib.rs b/_primitives/_rust/kei-buddy/src/lib.rs
index 54db0e2..34ad663 100644
--- a/_primitives/_rust/kei-buddy/src/lib.rs
+++ b/_primitives/_rust/kei-buddy/src/lib.rs
@@ -11,6 +11,7 @@
 //!   * `store`      — `BuddyStore` trait + `SqliteBuddyStore` impl
 
 pub mod chat_log;
+pub mod contacts;
 pub mod error;
 pub mod extractor;
 pub mod machine;
@@ -20,6 +21,7 @@ pub mod schema;
 pub mod state;
 pub mod store;
 pub(crate) mod store_ops;
+pub mod topics;
 pub mod transition;
 
 #[cfg(feature = "serve")]
@@ -28,9 +30,11 @@ pub mod serve;
 pub mod serve_telegram;
 
 pub use chat_log::ChatLog;
+pub use contacts::Contacts;
 pub use error::BuddyError;
 pub use extractor::LlmExtractor;
 pub use machine::handle_step;
 pub use state::OnboardState;
 pub use store::{BuddyStore, SqliteBuddyStore};
+pub use topics::Topics;
 pub use transition::StepOutput;
diff --git a/_primitives/_rust/kei-buddy/src/topics.rs b/_primitives/_rust/kei-buddy/src/topics.rs
new file mode 100644
index 0000000..9605443
--- /dev/null
+++ b/_primitives/_rust/kei-buddy/src/topics.rs
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: Apache-2.0
+//! `Topics` — async adapter storing topics + digests in kei-sage.
+//! Constructor Pattern: one responsibility — bridge kei-buddy to the
+//! kei-sage knowledge vault. All rusqlite calls via `spawn_blocking`.
+
+use std::path::Path;
+use std::sync::{Arc, Mutex};
+
+use kei_sage::{
+    edges::{add_edge, list_outgoing},
+    search::fts_search,
+    store::Store,
+    Unit,
+};
+use rusqlite::params;
+
+use crate::error::BuddyError;
+/// Wraps kei-sage `Store` with buddy-domain topic/digest API.
+pub struct Topics {
+    store: Arc<Mutex<Store>>,
+}
+
+impl Topics {
+    pub fn from_path(path: impl AsRef<Path>) -> Result<Self, BuddyError> {
+        let store = Store::open(path.as_ref())
+            .map_err(|e| BuddyError::Memory(format!("{e}")))?;
+        Ok(Self { store: Arc::new(Mutex::new(store)) })
+    }
+
+    pub fn from_memory() -> Result<Self, BuddyError> {
+        let store = Store::open_memory()
+            .map_err(|e| BuddyError::Memory(format!("{e}")))?;
+        Ok(Self { store: Arc::new(Mutex::new(store)) })
+    }
+
+    /// Add a topic; idempotent by `source_path`. Returns unit id.
+    pub async fn add_topic(
+        &self, chat_id: i64, slug: &str, title: &str, content: &str,
+    ) -> Result<i64, BuddyError> {
+        let src = format!("kei-buddy/chat-{chat_id}/topic/{slug}");
+        let unit = make_unit("buddy_topic", title, content, "", &src);
+        let store = Arc::clone(&self.store);
+        spawn(move || find_or_add(&store.lock().expect("poisoned"), &unit)).await
+    }
+
+    /// Add a digest note linked to a topic. Returns digest unit id.
+    pub async fn add_digest(
+        &self, chat_id: i64, topic_slug: &str, timestamp: i64, content: &str,
+    ) -> Result<i64, BuddyError> {
+        let topic_path = format!("kei-buddy/chat-{chat_id}/topic/{topic_slug}");
+        let dst = format!("kei-buddy/chat-{chat_id}/digest/{timestamp}");
+        let unit = make_unit("buddy_digest", &format!("digest-{timestamp}"), content, "E3", &dst);
+        let store = Arc::clone(&self.store);
+        spawn(move || {
+            let locked = store.lock().expect("poisoned");
+            let id = find_or_add(&locked, &unit)?;
+            add_edge(&locked, &topic_path, &dst, "digest_for", 1.0)
+                .map_err(|e| BuddyError::Memory(format!("{e}")))?;
+            Ok(id)
+        })
+        .await
+    }
+
+    /// Full-text search across all kei-buddy units.
+    pub async fn search(&self, q: &str, limit: i64) -> Result<Vec<Unit>, BuddyError> {
+        let store = Arc::clone(&self.store);
+        let q = q.to_string();
+        spawn(move || {
+            fts_search(&store.lock().expect("poisoned"), &q, limit)
+                .map_err(|e| BuddyError::Memory(format!("{e}")))
+        })
+        .await
+    }
+
+    /// List digest units linked from a topic via "digest_for" edges.
+    pub async fn digests_for(&self, chat_id: i64, slug: &str) -> Result<Vec<Unit>, BuddyError> {
+        let topic_path = format!("kei-buddy/chat-{chat_id}/topic/{slug}");
+        let store = Arc::clone(&self.store);
+        spawn(move || {
+            let locked = store.lock().expect("poisoned");
+            let edges = list_outgoing(&locked, &topic_path)
+                .map_err(|e| BuddyError::Memory(format!("{e}")))?;
+            let mut out = Vec::new();
+            for e in edges.into_iter().filter(|e| e.edge_type == "digest_for") {
+                if let Some(u) = unit_by_path(&locked, &e.dst_path)
+                    .map_err(|e| BuddyError::Memory(format!("{e}")))?
+                {
+                    out.push(u);
+                }
+            }
+            Ok(out)
+        })
+        .await
+    }
+
+    /// List all topic units for a chat via raw SELECT.
+    pub async fn list_topics(&self, chat_id: i64) -> Result<Vec<Unit>, BuddyError> {
+        let prefix = format!("kei-buddy/chat-{chat_id}/topic/%");
+        let store = Arc::clone(&self.store);
+        spawn(move || {
+            topics_by_prefix(&store.lock().expect("poisoned"), &prefix)
+                .map_err(|e| BuddyError::Memory(format!("{e}")))
+        })
+        .await
+    }
+}
+
+// ── Helpers ───────────────────────────────────────────────────────────────────
+fn make_unit(unit_type: &str, title: &str, content: &str, grade: &str, path: &str) -> Unit {
+    Unit {
+        id: 0, unit_type: unit_type.to_string(), title: title.to_string(),
+        content: content.to_string(), evidence_grade: grade.to_string(),
+        source_path: path.to_string(), vault_path: path.to_string(),
+        category: "kei-buddy".to_string(), created_at: 0, updated_at: 0,
+    }
+}
+
+fn find_or_add(store: &Store, unit: &Unit) -> Result<i64, BuddyError> {
+    let existing: Option<i64> = store.conn()
+        .query_row("SELECT id FROM knowledge_units WHERE source_path=?1 LIMIT 1",
+            params![unit.source_path], |r| r.get(0))
+        .ok();
+    if let Some(id) = existing { return Ok(id); }
+    store.add_unit(unit).map_err(|e| BuddyError::Memory(format!("{e}")))
+}
+
+fn unit_by_path(store: &Store, src: &str) -> anyhow::Result<Option<Unit>> {
+    let mut stmt = store.conn().prepare(
+        "SELECT id,unit_type,title,content,evidence_grade,source_path,vault_path,
+                category,created_at,updated_at FROM knowledge_units WHERE source_path=?1 LIMIT 1")?;
+    let mut rows = stmt.query(params![src])?;
+    if let Some(r) = rows.next()? { return Ok(Some(row_to_unit(r)?)); }
+    Ok(None)
+}
+
+fn topics_by_prefix(store: &Store, prefix: &str) -> anyhow::Result<Vec<Unit>> {
+    let mut stmt = store.conn().prepare(
+        "SELECT id,unit_type,title,content,evidence_grade,source_path,vault_path,
+                category,created_at,updated_at FROM knowledge_units
+         WHERE category='kei-buddy' AND unit_type='buddy_topic' AND source_path LIKE ?1")?;
+    let rows = stmt.query_map(params![prefix], row_to_unit)?;
+    let mut out = Vec::new();
+    for r in rows { out.push(r?); }
+    Ok(out)
+}
+
+fn row_to_unit(r: &rusqlite::Row) -> rusqlite::Result<Unit> {
+    Ok(Unit { id: r.get(0)?, unit_type: r.get(1)?, title: r.get(2)?,
+        content: r.get(3)?, evidence_grade: r.get(4)?, source_path: r.get(5)?,
+        vault_path: r.get(6)?, category: r.get(7)?, created_at: r.get(8)?, updated_at: r.get(9)? })
+}
+
+/// Thin wrapper: run closure in `spawn_blocking`, flatten join error.
+async fn spawn<F, T>(f: F) -> Result<T, BuddyError>
+where
+    F: FnOnce() -> Result<T, BuddyError> + Send + 'static,
+    T: Send + 'static,
+{
+    tokio::task::spawn_blocking(f)
+        .await
+        .map_err(|e| BuddyError::Memory(format!("spawn_blocking join: {e}")))?
+}
+
+// ── Tests ─────────────────────────────────────────────────────────────────────
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[tokio::test]
+    async fn add_topic_then_search_finds_it() {
+        let t = Topics::from_memory().unwrap();
+        t.add_topic(42, "ml", "ML Concepts", "talk about ml").await.unwrap();
+        let res = t.search("ml", 10).await.unwrap();
+        assert!(!res.is_empty());
+    }
+
+    #[tokio::test]
+    async fn add_topic_is_idempotent() {
+        let t = Topics::from_memory().unwrap();
+        t.add_topic(42, "ml", "ML Concepts", "first").await.unwrap();
+        t.add_topic(42, "ml", "ML Concepts", "second").await.unwrap();
+        assert_eq!(t.list_topics(42).await.unwrap().len(), 1);
+    }
+
+    #[tokio::test]
+    async fn add_digest_creates_edge_and_dest() {
+        let t = Topics::from_memory().unwrap();
+        t.add_topic(42, "ml", "ML Concepts", "about ml").await.unwrap();
+        t.add_digest(42, "ml", 1_000_000, "digest content").await.unwrap();
+        assert_eq!(t.digests_for(42, "ml").await.unwrap().len(), 1);
+    }
+
+    #[tokio::test]
+    async fn list_topics_scopes_per_chat() {
+        let t = Topics::from_memory().unwrap();
+        t.add_topic(1, "rust", "Rust", "rust stuff").await.unwrap();
+        t.add_topic(2, "go", "Go", "go stuff").await.unwrap();
+        assert_eq!(t.list_topics(1).await.unwrap().len(), 1);
+    }
+}