diff --git a/src/tools/mod.rs b/src/tools/mod.rs
index cee6c05..d36a66c 100644
--- a/src/tools/mod.rs
+++ b/src/tools/mod.rs
@@ -1,26 +1,37 @@
 pub mod bridge;
 pub mod devtools;
+pub mod identity;
+pub mod research;
 pub mod room_history;
 pub mod room_info;
 pub mod script;
 pub mod search;
 
+use std::collections::HashSet;
 use std::sync::Arc;
 
 use matrix_sdk::Client as MatrixClient;
+use matrix_sdk::RoomMemberships;
 use mistralai_client::v1::tool::Tool;
 use opensearch::OpenSearch;
 use serde_json::json;
+use tracing::debug;
 
 use crate::config::Config;
 use crate::context::ResponseContext;
+use crate::persistence::Store;
 use crate::sdk::gitea::GiteaClient;
+use crate::sdk::kratos::KratosClient;
+
 
 pub struct ToolRegistry {
     opensearch: OpenSearch,
     matrix: MatrixClient,
     config: Arc<Config>,
     gitea: Option<Arc<GiteaClient>>,
+    kratos: Option<Arc<KratosClient>>,
+    mistral: Option<Arc<mistralai_client::v1::client::Client>>,
+    store: Option<Arc<Store>>,
 }
 
 impl ToolRegistry {
@@ -29,12 +40,18 @@ impl ToolRegistry {
         matrix: MatrixClient,
         config: Arc<Config>,
         gitea: Option<Arc<GiteaClient>>,
+        kratos: Option<Arc<KratosClient>>,
+        mistral: Option<Arc<mistralai_client::v1::client::Client>>,
+        store: Option<Arc<Store>>,
     ) -> Self {
         Self {
             opensearch,
             matrix,
             config,
             gitea,
+            kratos,
+            mistral,
+            store,
         }
     }
 
@@ -42,7 +59,11 @@ impl ToolRegistry {
         self.gitea.is_some()
     }
 
-    pub fn tool_definitions(gitea_enabled: bool) -> Vec<Tool> {
+    pub fn has_kratos(&self) -> bool {
+        self.kratos.is_some()
+    }
+
+    pub fn tool_definitions(gitea_enabled: bool, kratos_enabled: bool) -> Vec<Tool> {
         let mut tools = vec![
             Tool::new(
                 "search_archive".into(),
@@ -172,14 +193,22 @@ impl ToolRegistry {
         if gitea_enabled {
             tools.extend(devtools::tool_definitions());
         }
+        if kratos_enabled {
+            tools.extend(identity::tool_definitions());
+        }
+
+        // Research tool (depth 0 — orchestrator level)
+        if let Some(def) = research::tool_definition(4, 0) {
+            tools.push(def);
+        }
 
         tools
     }
 
     /// Convert Sol's tool definitions to Mistral AgentTool format
     /// for use with the Agents API (orchestrator agent creation).
-    pub fn agent_tool_definitions(gitea_enabled: bool) -> Vec<mistralai_client::v1::agents::AgentTool> {
-        Self::tool_definitions(gitea_enabled)
+    pub fn agent_tool_definitions(gitea_enabled: bool, kratos_enabled: bool) -> Vec<mistralai_client::v1::agents::AgentTool> {
+        Self::tool_definitions(gitea_enabled, kratos_enabled)
             .into_iter()
             .map(|t| {
                 mistralai_client::v1::agents::AgentTool::function(
@@ -191,6 +220,60 @@ impl ToolRegistry {
             .collect()
     }
 
+    /// Compute the set of room IDs whose search results are visible from
+    /// the requesting room, based on member overlap.
+    ///
+    /// A room's results are visible if at least ROOM_OVERLAP_THRESHOLD of
+    /// its members are also members of the requesting room. This is enforced
+    /// at the query level — Sol never sees filtered-out results.
+    async fn allowed_room_ids(&self, requesting_room_id: &str) -> Vec<String> {
+        let rooms = self.matrix.joined_rooms();
+
+        // Get requesting room's member set
+        let requesting_room = rooms.iter().find(|r| r.room_id().as_str() == requesting_room_id);
+        let requesting_members: HashSet<String> = match requesting_room {
+            Some(room) => match room.members(RoomMemberships::JOIN).await {
+                Ok(members) => members.iter().map(|m| m.user_id().to_string()).collect(),
+                Err(_) => return vec![requesting_room_id.to_string()],
+            },
+            None => return vec![requesting_room_id.to_string()],
+        };
+
+        let mut allowed = Vec::new();
+        for room in &rooms {
+            let room_id = room.room_id().to_string();
+
+            // Always allow the requesting room itself
+            if room_id == requesting_room_id {
+                allowed.push(room_id);
+                continue;
+            }
+
+            let members: HashSet<String> = match room.members(RoomMemberships::JOIN).await {
+                Ok(m) => m.iter().map(|m| m.user_id().to_string()).collect(),
+                Err(_) => continue,
+            };
+
+            if members.is_empty() {
+                continue;
+            }
+
+            let overlap = members.intersection(&requesting_members).count();
+            let ratio = overlap as f64 / members.len() as f64;
+
+            if ratio >= self.config.behavior.room_overlap_threshold as f64 {
+                debug!(
+                    source_room = room_id.as_str(),
+                    overlap_pct = format!("{:.0}%", ratio * 100.0).as_str(),
+                    "Room passes overlap threshold"
+                );
+                allowed.push(room_id);
+            }
+        }
+
+        allowed
+    }
+
     pub async fn execute(
         &self,
         name: &str,
@@ -199,30 +282,36 @@ impl ToolRegistry {
     ) -> anyhow::Result<String> {
         match name {
             "search_archive" => {
+                let allowed = self.allowed_room_ids(&response_ctx.room_id).await;
                 search::search_archive(
                     &self.opensearch,
                     &self.config.opensearch.index,
                     arguments,
+                    &allowed,
                 )
                 .await
             }
             "get_room_context" => {
+                let allowed = self.allowed_room_ids(&response_ctx.room_id).await;
                 room_history::get_room_context(
                     &self.opensearch,
                     &self.config.opensearch.index,
                     arguments,
+                    &allowed,
                 )
                 .await
             }
             "list_rooms" => room_info::list_rooms(&self.matrix).await,
             "get_room_members" => room_info::get_room_members(&self.matrix, arguments).await,
             "run_script" => {
+                let allowed = self.allowed_room_ids(&response_ctx.room_id).await;
                 script::run_script(
                     &self.opensearch,
                     &self.matrix,
                     &self.config,
                     arguments,
                     response_ctx,
+                    allowed,
                 )
                 .await
             }
@@ -233,7 +322,53 @@ impl ToolRegistry {
                     anyhow::bail!("Gitea integration not configured")
                 }
             }
+            name if name.starts_with("identity_") => {
+                if let Some(ref kratos) = self.kratos {
+                    identity::execute(kratos, name, arguments).await
+                } else {
+                    anyhow::bail!("Identity (Kratos) integration not configured")
+                }
+            }
+            "research" => {
+                if let (Some(ref mistral), Some(ref store)) = (&self.mistral, &self.store) {
+                    anyhow::bail!("research tool requires execute_research() — call with room + event_id context")
+                } else {
+                    anyhow::bail!("Research not configured (missing mistral client or store)")
+                }
+            }
             _ => anyhow::bail!("Unknown tool: {name}"),
         }
     }
+
+    /// Execute a research tool call with full context (room, event_id for threads).
+    pub async fn execute_research(
+        self: &Arc<Self>,
+        arguments: &str,
+        response_ctx: &ResponseContext,
+        room: &matrix_sdk::room::Room,
+        event_id: &ruma::OwnedEventId,
+        current_depth: usize,
+    ) -> anyhow::Result<String> {
+        let mistral = self
+            .mistral
+            .as_ref()
+            .ok_or_else(|| anyhow::anyhow!("Research not configured: missing Mistral client"))?;
+        let store = self
+            .store
+            .as_ref()
+            .ok_or_else(|| anyhow::anyhow!("Research not configured: missing store"))?;
+
+        research::execute(
+            arguments,
+            &self.config,
+            mistral,
+            self,
+            response_ctx,
+            room,
+            event_id,
+            store,
+            current_depth,
+        )
+        .await
+    }
 }
diff --git a/src/tools/room_history.rs b/src/tools/room_history.rs
index d82131c..3e3424b 100644
--- a/src/tools/room_history.rs
+++ b/src/tools/room_history.rs
@@ -21,8 +21,14 @@ pub async fn get_room_context(
     client: &OpenSearch,
     index: &str,
     args_json: &str,
+    allowed_room_ids: &[String],
 ) -> anyhow::Result<String> {
     let args: RoomHistoryArgs = serde_json::from_str(args_json)?;
+
+    // Enforce room overlap — reject if the requested room isn't in the allowed set
+    if !allowed_room_ids.is_empty() && !allowed_room_ids.contains(&args.room_id) {
+        return Ok("Access denied: you don't have visibility into that room from here.".into());
+    }
     let total = args.before_count + args.after_count + 1;
 
     // Determine the pivot timestamp
diff --git a/src/tools/script.rs b/src/tools/script.rs
index 49dd8c4..8e51c1b 100644
--- a/src/tools/script.rs
+++ b/src/tools/script.rs
@@ -26,6 +26,7 @@ struct ScriptState {
     config: Arc<Config>,
     tmpdir: PathBuf,
     user_id: String,
+    allowed_room_ids: Vec<String>,
 }
 
 struct ScriptOutput(String);
@@ -83,17 +84,21 @@ async fn op_sol_search(
     #[string] query: String,
     #[string] opts_json: String,
 ) -> Result<String, JsErrorBox> {
-    let (os, index) = {
+    let (os, index, allowed) = {
         let st = state.borrow();
         let ss = st.borrow::<ScriptState>();
-        (ss.opensearch.clone(), ss.config.opensearch.index.clone())
+        (
+            ss.opensearch.clone(),
+            ss.config.opensearch.index.clone(),
+            ss.allowed_room_ids.clone(),
+        )
     };
 
     let mut args: serde_json::Value =
         serde_json::from_str(&opts_json).unwrap_or(serde_json::json!({}));
     args["query"] = serde_json::Value::String(query);
 
-    super::search::search_archive(&os, &index, &args.to_string())
+    super::search::search_archive(&os, &index, &args.to_string(), &allowed)
         .await
         .map_err(|e| JsErrorBox::generic(e.to_string()))
 }
@@ -429,6 +434,7 @@ pub async fn run_script(
     config: &Config,
     args_json: &str,
     response_ctx: &ResponseContext,
+    allowed_room_ids: Vec<String>,
 ) -> anyhow::Result<String> {
     let args: RunScriptArgs = serde_json::from_str(args_json)?;
     let code = args.code.clone();
@@ -494,6 +500,7 @@ pub async fn run_script(
                     config: cfg,
                     tmpdir: tmpdir_path,
                     user_id,
+                    allowed_room_ids,
                 });
             }
 
diff --git a/src/tools/search.rs b/src/tools/search.rs
index f761820..67a3a38 100644
--- a/src/tools/search.rs
+++ b/src/tools/search.rs
@@ -23,7 +23,8 @@ pub struct SearchArgs {
 fn default_limit() -> usize { 10 }
 
 /// Build the OpenSearch query body from parsed SearchArgs. Extracted for testability.
-pub fn build_search_query(args: &SearchArgs) -> serde_json::Value {
+/// `allowed_room_ids` restricts results to rooms that pass the member overlap check.
+pub fn build_search_query(args: &SearchArgs, allowed_room_ids: &[String]) -> serde_json::Value {
     // Handle empty/wildcard queries as match_all
     let must = if args.query.is_empty() || args.query == "*" {
         vec![json!({ "match_all": {} })]
@@ -37,6 +38,12 @@ pub fn build_search_query(args: &SearchArgs) -> serde_json::Value {
         "term": { "redacted": false }
     })];
 
+    // Restrict to rooms that pass the member overlap threshold.
+    // This is a system-level security filter — Sol never sees results from excluded rooms.
+    if !allowed_room_ids.is_empty() {
+        filter.push(json!({ "terms": { "room_id": allowed_room_ids } }));
+    }
+
     if let Some(ref room) = args.room {
         filter.push(json!({ "term": { "room_name": room } }));
     }
@@ -76,9 +83,10 @@ pub async fn search_archive(
     client: &OpenSearch,
     index: &str,
     args_json: &str,
+    allowed_room_ids: &[String],
 ) -> anyhow::Result<String> {
     let args: SearchArgs = serde_json::from_str(args_json)?;
-    let query_body = build_search_query(&args);
+    let query_body = build_search_query(&args, allowed_room_ids);
 
     info!(
         query = args.query.as_str(),
@@ -174,7 +182,7 @@ mod tests {
     #[test]
     fn test_query_basic() {
         let args = parse_args(r#"{"query": "test"}"#);
-        let q = build_search_query(&args);
+        let q = build_search_query(&args, &[]);
 
         assert_eq!(q["size"], 10);
         assert_eq!(q["query"]["bool"]["must"][0]["match"]["content"], "test");
@@ -185,7 +193,7 @@ mod tests {
     #[test]
     fn test_query_with_room_filter() {
         let args = parse_args(r#"{"query": "hello", "room": "design"}"#);
-        let q = build_search_query(&args);
+        let q = build_search_query(&args, &[]);
 
         let filters = q["query"]["bool"]["filter"].as_array().unwrap();
         assert_eq!(filters.len(), 2);
@@ -195,7 +203,7 @@ mod tests {
     #[test]
     fn test_query_with_sender_filter() {
         let args = parse_args(r#"{"query": "hello", "sender": "Bob"}"#);
-        let q = build_search_query(&args);
+        let q = build_search_query(&args, &[]);
 
         let filters = q["query"]["bool"]["filter"].as_array().unwrap();
         assert_eq!(filters.len(), 2);
@@ -205,7 +213,7 @@ mod tests {
     #[test]
     fn test_query_with_room_and_sender() {
         let args = parse_args(r#"{"query": "hello", "room": "dev", "sender": "Carol"}"#);
-        let q = build_search_query(&args);
+        let q = build_search_query(&args, &[]);
 
         let filters = q["query"]["bool"]["filter"].as_array().unwrap();
         assert_eq!(filters.len(), 3);
@@ -220,7 +228,7 @@ mod tests {
             "after": "1710000000000",
             "before": "1710100000000"
         }"#);
-        let q = build_search_query(&args);
+        let q = build_search_query(&args, &[]);
 
         let filters = q["query"]["bool"]["filter"].as_array().unwrap();
         let range_filter = &filters[1]["range"]["timestamp"];
@@ -231,7 +239,7 @@ mod tests {
     #[test]
     fn test_query_with_after_only() {
         let args = parse_args(r#"{"query": "hello", "after": "1710000000000"}"#);
-        let q = build_search_query(&args);
+        let q = build_search_query(&args, &[]);
 
         let filters = q["query"]["bool"]["filter"].as_array().unwrap();
         let range_filter = &filters[1]["range"]["timestamp"];
@@ -242,7 +250,7 @@ mod tests {
     #[test]
     fn test_query_with_custom_limit() {
         let args = parse_args(r#"{"query": "hello", "limit": 50}"#);
-        let q = build_search_query(&args);
+        let q = build_search_query(&args, &[]);
         assert_eq!(q["size"], 50);
     }
 
@@ -256,7 +264,7 @@ mod tests {
             "before": "2000",
             "limit": 5
         }"#);
-        let q = build_search_query(&args);
+        let q = build_search_query(&args, &[]);
 
         assert_eq!(q["size"], 5);
         let filters = q["query"]["bool"]["filter"].as_array().unwrap();
@@ -267,7 +275,7 @@ mod tests {
     #[test]
     fn test_invalid_timestamp_ignored() {
         let args = parse_args(r#"{"query": "hello", "after": "not-a-number"}"#);
-        let q = build_search_query(&args);
+        let q = build_search_query(&args, &[]);
 
         let filters = q["query"]["bool"]["filter"].as_array().unwrap();
         // Only the redacted filter, no range since parse failed
@@ -277,14 +285,14 @@ mod tests {
     #[test]
     fn test_wildcard_query_uses_match_all() {
         let args = parse_args(r#"{"query": "*"}"#);
-        let q = build_search_query(&args);
+        let q = build_search_query(&args, &[]);
         assert!(q["query"]["bool"]["must"][0]["match_all"].is_object());
     }
 
     #[test]
     fn test_empty_query_uses_match_all() {
         let args = parse_args(r#"{"query": ""}"#);
-        let q = build_search_query(&args);
+        let q = build_search_query(&args, &[]);
         assert!(q["query"]["bool"]["must"][0]["match_all"].is_object());
     }
 
@@ -292,7 +300,7 @@ mod tests {
     fn test_room_filter_uses_keyword_field() {
         // room_name is mapped as "keyword" in OpenSearch — no .keyword subfield
         let args = parse_args(r#"{"query": "test", "room": "general"}"#);
-        let q = build_search_query(&args);
+        let q = build_search_query(&args, &[]);
         let filters = q["query"]["bool"]["filter"].as_array().unwrap();
         // Should be room_name, NOT room_name.keyword
         assert_eq!(filters[1]["term"]["room_name"], "general");
@@ -301,7 +309,7 @@ mod tests {
     #[test]
     fn test_source_fields() {
         let args = parse_args(r#"{"query": "test"}"#);
-        let q = build_search_query(&args);
+        let q = build_search_query(&args, &[]);
 
         let source = q["_source"].as_array().unwrap();
         let fields: Vec<&str> = source.iter().map(|v| v.as_str().unwrap()).collect();