diff --git a/Cargo.lock b/Cargo.lock
index 28a1a7d2..001ca1df 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1378,6 +1378,8 @@ dependencies = [
  "futures-util",
  "hive-sh4re",
  "matrix-sdk",
+ "mime",
+ "mime_guess",
  "reqwest",
  "rmcp",
  "schemars",
diff --git a/hive-matrix-mcp/Cargo.toml b/hive-matrix-mcp/Cargo.toml
index 9f74495a..5dd9d32c 100644
--- a/hive-matrix-mcp/Cargo.toml
+++ b/hive-matrix-mcp/Cargo.toml
@@ -11,6 +11,8 @@ anyhow.workspace = true
 futures-util.workspace = true
 hive-sh4re.workspace = true
 matrix-sdk.workspace = true
+mime = "0.3"
+mime_guess = "2"
 reqwest.workspace = true
 rmcp.workspace = true
 schemars.workspace = true
diff --git a/hive-matrix-mcp/src/bin/mcp.rs b/hive-matrix-mcp/src/bin/mcp.rs
index 8616414e..778e5eec 100644
--- a/hive-matrix-mcp/src/bin/mcp.rs
+++ b/hive-matrix-mcp/src/bin/mcp.rs
@@ -79,6 +79,32 @@ struct SendDmArgs {
     body: String,
 }
 
+#[derive(Debug, Deserialize, JsonSchema)]
+struct SendFileArgs {
+    /// Matrix room id (`!abc:server`) or canonical alias (`#name:server`).
+    room: String,
+    /// Absolute path to a local file readable by the agent (e.g. a built
+    /// PDF under the agent's workspace). MIME type is inferred from the
+    /// extension. 50 MiB cap.
+    path: String,
+    /// Optional caption, sent as a follow-up text message in the room.
+    #[serde(default)]
+    caption: Option<String>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+struct SendFileDmArgs {
+    /// Matrix user id of the recipient (`@user:server`). DM room is
+    /// created if one doesn't already exist.
+    user_id: String,
+    /// Absolute path to a local file readable by the agent. MIME type is
+    /// inferred from the extension. 50 MiB cap.
+    path: String,
+    /// Optional caption, sent as a follow-up text message in the DM.
+    #[serde(default)]
+    caption: Option<String>,
+}
+
 #[derive(Debug, Deserialize, JsonSchema)]
 struct SendReactionArgs {
     room: String,
@@ -196,6 +222,42 @@ impl MatrixBridge {
         )
     }
 
+    #[tool(
+        description = "Upload a local file and post it as an attachment to a matrix \
+            room. `room` is a room id (!abc:server) or alias (#name:server); `path` \
+            is an absolute path to a local file (MIME inferred from extension, 50 MiB \
+            cap); optional `caption` is sent as a follow-up message. Rejected if the \
+            room has unread messages — read_room then mark_read first."
+    )]
+    async fn send_file(&self, Parameters(args): Parameters<SendFileArgs>) -> String {
+        render(
+            round_trip(DaemonRequest::SendFile {
+                room: args.room,
+                path: args.path,
+                caption: args.caption,
+            })
+            .await,
+        )
+    }
+
+    #[tool(
+        description = "Open (or reuse) a DM with `user_id` (@user:server) and upload \
+            a local file as an attachment. `path` is an absolute local file path (MIME \
+            inferred, 50 MiB cap); optional `caption` is sent as a follow-up message. \
+            If the DM room already exists with unread messages, the send is rejected \
+            — read_room then mark_read first."
+    )]
+    async fn send_file_dm(&self, Parameters(args): Parameters<SendFileDmArgs>) -> String {
+        render(
+            round_trip(DaemonRequest::SendFileDm {
+                user_id: args.user_id,
+                path: args.path,
+                caption: args.caption,
+            })
+            .await,
+        )
+    }
+
     #[tool(
         description = "React to a specific matrix event with an emoji or short \
             string `key`. Matrix-spec annotation; renders as a reaction in \
diff --git a/hive-matrix-mcp/src/handlers.rs b/hive-matrix-mcp/src/handlers.rs
index eff7bda9..e010f949 100644
--- a/hive-matrix-mcp/src/handlers.rs
+++ b/hive-matrix-mcp/src/handlers.rs
@@ -184,25 +184,33 @@ pub async fn send_message(client: &Client, room_ref: &str, body: &str) -> Daemon
     }
 }
 
+/// Find the existing DM room with `user_id` or create one. Shared by
+/// `send_dm` and `send_file_dm`. `direct_targets()` (cached state) is
+/// used rather than the async `is_direct()`.
+async fn resolve_or_create_dm(
+    client: &Client,
+    user_id: &str,
+) -> Result<matrix_sdk::Room, DaemonResponse> {
+    let uid: OwnedUserId = user_id
+        .parse()
+        .map_err(|e| DaemonResponse::error(format!("invalid user_id {user_id}: {e}")))?;
+    if let Some(room) = client
+        .joined_rooms()
+        .into_iter()
+        .find(|r| r.direct_targets().iter().any(|t| t.as_str() == uid.as_str()))
+    {
+        return Ok(room);
+    }
+    client
+        .create_dm(&uid)
+        .await
+        .map_err(|e| DaemonResponse::error(format!("create_dm {uid}: {e}")))
+}
+
 pub async fn send_dm(client: &Client, user_id: &str, body: &str) -> DaemonResponse {
-    let uid: OwnedUserId = match user_id.parse() {
-        Ok(u) => u,
-        Err(e) => return DaemonResponse::error(format!("invalid user_id {user_id}: {e}")),
-    };
-    // Find existing DM or create one.
-    let room = client.joined_rooms().into_iter().find(|r| {
-        // is_direct() is async; check direct_targets() instead which
-        // reads from cached state.
-        r.direct_targets()
-            .iter()
-            .any(|t| t.as_str() == uid.as_str())
-    });
-    let room = match room {
-        Some(r) => r,
-        None => match client.create_dm(&uid).await {
-            Ok(r) => r,
-            Err(e) => return DaemonResponse::error(format!("create_dm {uid}: {e}")),
-        },
+    let room = match resolve_or_create_dm(client, user_id).await {
+        Ok(r) => r,
+        Err(e) => return e,
     };
     if let Some(reject) = unread_guard(&room) {
         return reject;
@@ -212,12 +220,106 @@ pub async fn send_dm(client: &Client, user_id: &str, body: &str) -> DaemonRespon
         Ok(resp) => DaemonResponse::ok(&serde_json::json!({
             "event_id": resp.event_id.to_string(),
             "room_id": room.room_id().to_string(),
-            "user_id": uid.to_string(),
+            "user_id": user_id,
         })),
-        Err(e) => DaemonResponse::error(format!("send DM to {uid}: {e}")),
+        Err(e) => DaemonResponse::error(format!("send DM to {user_id}: {e}")),
     }
 }
 
+/// Maximum file size accepted by `send_file` / `send_file_dm`.
+const MAX_UPLOAD_BYTES: u64 = 50 * 1024 * 1024;
+
+/// Read a local file and post it as a matrix attachment to `room`,
+/// inferring the MIME type from the file extension. An optional
+/// `caption` is sent as a best-effort follow-up text message (the
+/// attachment has already landed, so a caption failure is non-fatal).
+/// Shared by `send_file` and `send_file_dm`.
+async fn upload_attachment(
+    room: &matrix_sdk::Room,
+    path: &str,
+    caption: Option<&str>,
+) -> DaemonResponse {
+    let p = std::path::Path::new(path);
+    let meta = match tokio::fs::metadata(p).await {
+        Ok(m) => m,
+        Err(e) => return DaemonResponse::error(format!("stat {path}: {e}")),
+    };
+    if !meta.is_file() {
+        return DaemonResponse::error(format!("{path} is not a regular file"));
+    }
+    if meta.len() > MAX_UPLOAD_BYTES {
+        return DaemonResponse::error(format!(
+            "{path} is {} bytes, over the {MAX_UPLOAD_BYTES}-byte upload cap",
+            meta.len()
+        ));
+    }
+    let data = match tokio::fs::read(p).await {
+        Ok(d) => d,
+        Err(e) => return DaemonResponse::error(format!("read {path}: {e}")),
+    };
+    let filename = p
+        .file_name()
+        .and_then(|n| n.to_str())
+        .unwrap_or("file")
+        .to_owned();
+    let content_type: mime::Mime = mime_guess::from_path(p).first_or_octet_stream();
+    let resp = match room
+        .send_attachment(
+            filename.clone(),
+            &content_type,
+            data,
+            matrix_sdk::attachment::AttachmentConfig::new(),
+        )
+        .await
+    {
+        Ok(r) => r,
+        Err(e) => {
+            return DaemonResponse::error(format!("send attachment to {}: {e}", room.room_id()));
+        }
+    };
+    if let Some(c) = caption.filter(|c| !c.is_empty()) {
+        let _ = room.send(RoomMessageEventContent::text_markdown(c)).await;
+    }
+    DaemonResponse::ok(&serde_json::json!({
+        "event_id": resp.event_id.to_string(),
+        "room_id": room.room_id().to_string(),
+        "filename": filename,
+        "mime": content_type.essence_str(),
+    }))
+}
+
+pub async fn send_file(
+    client: &Client,
+    room_ref: &str,
+    path: &str,
+    caption: Option<&str>,
+) -> DaemonResponse {
+    let room = match resolve_room(client, room_ref).await {
+        Ok(r) => r,
+        Err(e) => return e,
+    };
+    if let Some(reject) = unread_guard(&room) {
+        return reject;
+    }
+    upload_attachment(&room, path, caption).await
+}
+
+pub async fn send_file_dm(
+    client: &Client,
+    user_id: &str,
+    path: &str,
+    caption: Option<&str>,
+) -> DaemonResponse {
+    let room = match resolve_or_create_dm(client, user_id).await {
+        Ok(r) => r,
+        Err(e) => return e,
+    };
+    if let Some(reject) = unread_guard(&room) {
+        return reject;
+    }
+    upload_attachment(&room, path, caption).await
+}
+
 pub async fn send_reaction(
     client: &Client,
     room_ref: &str,
diff --git a/hive-matrix-mcp/src/protocol.rs b/hive-matrix-mcp/src/protocol.rs
index bd71884f..64c4392e 100644
--- a/hive-matrix-mcp/src/protocol.rs
+++ b/hive-matrix-mcp/src/protocol.rs
@@ -27,6 +27,26 @@ pub enum DaemonRequest {
     #[serde(rename = "send_dm")]
     SendDm { user_id: String, body: String },
 
+    /// Upload a local file and post it as an attachment to `room`
+    /// (id or alias). `caption`, when set, is sent as a follow-up
+    /// text message in the same room.
+    #[serde(rename = "send_file")]
+    SendFile {
+        room: String,
+        path: String,
+        caption: Option<String>,
+    },
+
+    /// Open (or reuse) a DM with `user_id` and post a local file as an
+    /// attachment. `caption`, when set, is sent as a follow-up text
+    /// message in the DM.
+    #[serde(rename = "send_file_dm")]
+    SendFileDm {
+        user_id: String,
+        path: String,
+        caption: Option<String>,
+    },
+
     /// React to a specific event with an emoji `key`. Matrix-spec
     /// `m.reaction` annotation.
     #[serde(rename = "send_reaction")]
diff --git a/hive-matrix-mcp/src/socket.rs b/hive-matrix-mcp/src/socket.rs
index 0f09b876..8ba5a5e2 100644
--- a/hive-matrix-mcp/src/socket.rs
+++ b/hive-matrix-mcp/src/socket.rs
@@ -65,6 +65,16 @@ async fn dispatch(req: DaemonRequest, client: &Client) -> DaemonResponse {
             handlers::send_message(client, &room, &body).await
         }
         DaemonRequest::SendDm { user_id, body } => handlers::send_dm(client, &user_id, &body).await,
+        DaemonRequest::SendFile {
+            room,
+            path,
+            caption,
+        } => handlers::send_file(client, &room, &path, caption.as_deref()).await,
+        DaemonRequest::SendFileDm {
+            user_id,
+            path,
+            caption,
+        } => handlers::send_file_dm(client, &user_id, &path, caption.as_deref()).await,
         DaemonRequest::SendReaction {
             room,
             event_id,