feat: add hide/close DM support (Slack-style DM management)

crates/sprout-db/src/channel.rs

@@ -730,6 +730,7 @@ pub async fn get_accessible_channels(
             ON c.id = cm.channel_id AND cm.pubkey = $1 AND cm.removed_at IS NULL
         WHERE c.deleted_at IS NULL
           {membership_clause}
+          AND (c.channel_type != 'dm' OR cm.hidden_at IS NULL)
     "#
     );
 

crates/sprout-db/src/dm.rs

@@ -243,6 +243,7 @@ pub async fn list_dms_for_user(
                 ON c.id = cm.channel_id
                AND cm.pubkey = $1
                AND cm.removed_at IS NULL
+               AND cm.hidden_at IS NULL
             WHERE c.channel_type = 'dm'
               AND c.deleted_at IS NULL
               AND c.updated_at < $2
@@ -264,6 +265,7 @@ pub async fn list_dms_for_user(
                 ON c.id = cm.channel_id
                AND cm.pubkey = $1
                AND cm.removed_at IS NULL
+               AND cm.hidden_at IS NULL
             WHERE c.channel_type = 'dm'
               AND c.deleted_at IS NULL
             ORDER BY c.updated_at DESC
@@ -350,6 +352,8 @@ pub async fn open_dm(
 
     // Check for existing DM first (fast path, no transaction).
     if let Some(existing) = find_dm_by_participants(pool, &hash).await? {
+        // Clear hidden_at for the caller so the DM reappears in their sidebar.
+        unhide_dm(pool, existing.id, created_by).await?;
         return Ok((existing, false));
     }
 
@@ -359,6 +363,55 @@ pub async fn open_dm(
     Ok((channel, true))
 }
 
+// -- Hide / unhide ------------------------------------------------------------
+
+/// Hide a DM for a specific user by setting `hidden_at = NOW()`.
+///
+/// The DM is not deleted — it can be restored by opening a new DM with the
+/// same participants (which clears `hidden_at`). Returns an error if the user
+/// is not an active member of the channel.
+pub async fn hide_dm(pool: &PgPool, channel_id: Uuid, pubkey: &[u8]) -> Result<()> {
+    let result = sqlx::query(
+        r#"
+        UPDATE channel_members
+        SET hidden_at = NOW()
+        WHERE channel_id = $1 AND pubkey = $2 AND removed_at IS NULL
+        "#,
+    )
+    .bind(channel_id)
+    .bind(pubkey)
+    .execute(pool)
+    .await?;
+
+    if result.rows_affected() == 0 {
+        return Err(DbError::NotFound(format!(
+            "no active membership for channel {channel_id}"
+        )));
+    }
+
+    Ok(())
+}
+
+/// Unhide a DM for a specific user by clearing `hidden_at`.
+///
+/// This is called automatically when a user re-opens a DM via [`open_dm`].
+/// It is a no-op if the membership is not currently hidden.
+pub async fn unhide_dm(pool: &PgPool, channel_id: Uuid, pubkey: &[u8]) -> Result<()> {
+    sqlx::query(
+        r#"
+        UPDATE channel_members
+        SET hidden_at = NULL
+        WHERE channel_id = $1 AND pubkey = $2 AND removed_at IS NULL
+        "#,
+    )
+    .bind(channel_id)
+    .bind(pubkey)
+    .execute(pool)
+    .await?;
+
+    Ok(())
+}
+
 // -- Row mapping --------------------------------------------------------------
 
 fn row_to_channel_record(row: sqlx::postgres::PgRow) -> Result<ChannelRecord> {

crates/sprout-db/src/lib.rs

@@ -548,6 +548,19 @@ impl Db {
         dm::open_dm(&self.pool, pubkeys, created_by).await
     }
 
+    /// Hide a DM channel for a specific user.
+    ///
+    /// The DM is not deleted — it can be restored by opening a new DM with
+    /// the same participants.
+    pub async fn hide_dm(&self, channel_id: Uuid, pubkey: &[u8]) -> Result<()> {
+        dm::hide_dm(&self.pool, channel_id, pubkey).await
+    }
+
+    /// Unhide a DM channel for a specific user.
+    pub async fn unhide_dm(&self, channel_id: Uuid, pubkey: &[u8]) -> Result<()> {
+        dm::unhide_dm(&self.pool, channel_id, pubkey).await
+    }
+
     // ── Threads ──────────────────────────────────────────────────────────────
 
     /// Insert thread metadata.

crates/sprout-mcp/src/server.rs

@@ -409,6 +409,13 @@ pub struct AddDmMemberParams {
     pub pubkey: String,
 }
 
+/// Parameters for the `hide_dm` tool.
+#[derive(Debug, Serialize, Deserialize, schemars::JsonSchema)]
+pub struct HideDmParams {
+    /// UUID of the DM channel to hide.
+    pub channel_id: String,
+}
+
 // ── Reaction tool parameter structs ──────────────────────────────────────────
 
 /// Parameters for the `add_reaction` tool.
@@ -1662,6 +1669,34 @@ with kind:45003 comments)."
         }
     }
 
+    /// Hide a DM channel from the agent's DM list.
+    #[tool(
+        name = "hide_dm",
+        description = "Hide a direct message channel from the agent's DM list. The DM can be restored by opening a new DM with the same participants."
+    )]
+    pub async fn hide_dm(&self, Parameters(p): Parameters<HideDmParams>) -> String {
+        if let Err(e) = validate_uuid(&p.channel_id) {
+            return format!("Error: {e}");
+        }
+        match self
+            .client
+            .post(
+                &format!("/api/dms/{}/hide", p.channel_id),
+                &serde_json::json!({}),
+            )
+            .await
+        {
+            Ok(b) => {
+                if b.is_empty() {
+                    "DM hidden successfully.".to_string()
+                } else {
+                    b
+                }
+            }
+            Err(e) => format!("Error: {e}"),
+        }
+    }
+
     // ── Reaction tools ────────────────────────────────────────────────────────
 
     /// Add an emoji reaction to a message.

crates/sprout-mcp/src/toolsets.rs

@@ -21,7 +21,7 @@
 //! |-----------------|-------|
 //! | `default`       | 25    |
 //! | `channel_admin` | 6     |
-//! | `dms`           | 2     |
+//! | `dms`           | 3     |
 //! | `canvas`        | 2     |
 //! | `workflow_admin`| 5     |
 //! | `identity`      | 1     |
@@ -40,7 +40,7 @@ use std::sync::LazyLock;
 /// classification. `is_read = true` means the tool is safe to include under
 /// a `:ro` (read-only) mode restriction.
 ///
-/// 42 tools total. See [`DEFERRED_TOOLS`] for tools planned but not yet implemented.
+/// 43 tools total. See [`DEFERRED_TOOLS`] for tools planned but not yet implemented.
 pub const ALL_TOOLS: &[(&str, &str, bool)] = &[
     // ── default ─────────────────────────────────────────────────────────────
     ("send_message", "default", false),
@@ -77,6 +77,7 @@ pub const ALL_TOOLS: &[(&str, &str, bool)] = &[
     ("list_channel_members", "channel_admin", true),
     // ── dms ──────────────────────────────────────────────────────────────────
     ("add_dm_member", "dms", false),
+    ("hide_dm", "dms", false),
     ("list_dms", "dms", true),
     // ── canvas ───────────────────────────────────────────────────────────────
     ("get_canvas", "canvas", true),
@@ -370,8 +371,8 @@ mod tests {
     }
 
     #[test]
-    fn all_tools_count_is_42() {
-        assert_eq!(ALL_TOOLS.len(), 42);
+    fn all_tools_count_is_43() {
+        assert_eq!(ALL_TOOLS.len(), 43);
     }
 
     #[test]

crates/sprout-relay/src/api/dms.rs

@@ -3,6 +3,7 @@
 //! Endpoints:
 //!   POST /api/dms                      — Open or create a DM (idempotent)
 //!   POST /api/dms/{channel_id}/members — Add member to group DM (creates new DM)
+//!   POST /api/dms/{channel_id}/hide    — Hide a DM from the user's sidebar
 //!   GET  /api/dms                      — List user's DM conversations
 
 use std::sync::Arc;
@@ -362,6 +363,54 @@ pub async fn list_dms_handler(
     })))
 }
 
+/// `POST /api/dms/{channel_id}/hide` — Hide a DM from the caller's sidebar.
+///
+/// The DM is not deleted — it can be restored by opening a new DM with the
+/// same participants. Returns 204 No Content on success.
+pub async fn hide_dm_handler(
+    State(state): State<Arc<AppState>>,
+    headers: HeaderMap,
+    Path(channel_id_str): Path<String>,
+) -> Result<StatusCode, (StatusCode, Json<serde_json::Value>)> {
+    let ctx = extract_auth_context(&headers, &state).await?;
+    sprout_auth::require_scope(&ctx.scopes, sprout_auth::Scope::MessagesWrite)
+        .map_err(super::scope_error)?;
+
+    let channel_id: Uuid = channel_id_str
+        .parse()
+        .map_err(|_| api_error(StatusCode::BAD_REQUEST, "invalid channel_id format"))?;
+
+    // Verify the channel exists and is a DM.
+    let channel = state
+        .db
+        .get_channel(channel_id)
+        .await
+        .map_err(|_| super::not_found("DM not found"))?;
+
+    if channel.channel_type != "dm" {
+        return Err(api_error(StatusCode::BAD_REQUEST, "channel is not a DM"));
+    }
+
+    // Verify caller is a member.
+    let is_member = state
+        .db
+        .is_member(channel_id, &ctx.pubkey_bytes)
+        .await
+        .map_err(|e| internal_error(&format!("db error: {e}")))?;
+
+    if !is_member {
+        return Err(super::forbidden("not a member of this DM"));
+    }
+
+    state
+        .db
+        .hide_dm(channel_id, &ctx.pubkey_bytes)
+        .await
+        .map_err(|e| internal_error(&format!("db error: {e}")))?;
+
+    Ok(StatusCode::NO_CONTENT)
+}
+
 // ── Helpers ───────────────────────────────────────────────────────────────────
 
 /// Fetch and format participant info for a DM channel.

crates/sprout-relay/src/api/mod.rs

@@ -58,7 +58,7 @@ pub use channels_metadata::{
     archive_channel_handler, delete_channel_handler, get_channel_handler, set_purpose_handler,
     set_topic_handler, unarchive_channel_handler, update_channel_handler,
 };
-pub use dms::{add_dm_member_handler, list_dms_handler, open_dm_handler};
+pub use dms::{add_dm_member_handler, hide_dm_handler, list_dms_handler, open_dm_handler};
 pub use events::get_event;
 pub use feed::feed_handler;
 pub use members::{add_members, join_channel, leave_channel, list_members, remove_member};

crates/sprout-relay/src/router.rs

@@ -146,6 +146,7 @@ pub fn build_router(state: Arc<AppState>) -> Router {
             "/api/dms/{channel_id}/members",
             post(api::add_dm_member_handler),
         )
+        .route("/api/dms/{channel_id}/hide", post(api::hide_dm_handler))
         // Message delete + edit routes
         .route(
             "/api/messages/{event_id}",

crates/sprout-test-client/tests/e2e_mcp.rs

@@ -102,7 +102,7 @@ fn spawn_mcp_server(keys: &Keys) -> Child {
         ])
         .env("SPROUT_RELAY_URL", relay_ws_url())
         .env("SPROUT_PRIVATE_KEY", &nsec)
-        // Tests exercise all 42 tools — enable every toolset.
+        // Tests exercise all 43 tools — enable every toolset.
         .env("SPROUT_TOOLSETS", "all")
         // Prevent a stale SPROUT_API_TOKEN from the host .env leaking into
         // the subprocess and causing NIP-42 auth failures against a fresh DB.
@@ -251,7 +251,7 @@ impl McpSession {
 // ── Tests ─────────────────────────────────────────────────────────────────────
 
 /// Spawn the MCP server, complete the initialize handshake, and verify that
-/// all 42 expected tools are listed by `tools/list`.
+/// all 43 expected tools are listed by `tools/list`.
 #[tokio::test]
 #[ignore]
 async fn test_mcp_initialize_and_list_tools() {
@@ -300,8 +300,8 @@ async fn test_mcp_initialize_and_list_tools() {
 
     assert_eq!(
         tools.len(),
-        42,
-        "expected exactly 42 tools, got {}. Tools: {:?}",
+        43,
+        "expected exactly 43 tools, got {}. Tools: {:?}",
         tools.len(),
         tools
             .iter()
@@ -332,6 +332,7 @@ async fn test_mcp_initialize_and_list_tools() {
         "get_thread",
         "get_users",
         "get_workflow_runs",
+        "hide_dm",
         "join_channel",
         "leave_channel",
         "list_channel_members",

desktop/scripts/check-file-sizes.mjs

@@ -33,7 +33,7 @@ const overrides = new Map([
   ["src-tauri/src/managed_agents/persona_card.rs", 700], // PNG/ZIP persona card codec + 21 unit tests (~300 lines of tests)
   ["src/app/AppShell.tsx", 775],
   ["src/features/agents/ui/AgentsView.tsx", 625], // persona/team orchestration plus import/export wiring
-  ["src/features/channels/hooks.ts", 525], // canvas query + mutation hooks
+  ["src/features/channels/hooks.ts", 550], // canvas query + mutation hooks + DM hide mutation
   ["src/features/channels/ui/ChannelManagementSheet.tsx", 800],
   ["src/features/messages/ui/MessageComposer.tsx", 665], // media upload handlers (paste, drop, dialog) + channelId reset effect
   ["src/features/settings/ui/SettingsView.tsx", 600],

desktop/src-tauri/src/commands/dms.rs

@@ -4,7 +4,7 @@ use tauri::State;
 use crate::{
     app_state::AppState,
     models::{ChannelInfo, OpenDmBody, OpenDmResponse},
-    relay::{build_authed_request, send_json_request},
+    relay::{build_authed_request, send_empty_request, send_json_request},
 };
 
 #[tauri::command]
@@ -20,3 +20,13 @@ pub async fn open_dm(
     let request = build_authed_request(&state.http_client, Method::GET, &path, &state)?;
     send_json_request(request).await
 }
+
+#[tauri::command]
+pub async fn hide_dm(
+    channel_id: String,
+    state: State<'_, AppState>,
+) -> Result<(), String> {
+    let path = format!("/api/dms/{channel_id}/hide");
+    let request = build_authed_request(&state.http_client, Method::POST, &path, &state)?;
+    send_empty_request(request).await
+}

desktop/src-tauri/src/lib.rs

@@ -209,6 +209,7 @@ pub fn run() {
             get_channels,
             create_channel,
             open_dm,
+            hide_dm,
             get_channel_details,
             get_channel_members,
             update_channel,

desktop/src/app/AppShell.tsx

@@ -10,6 +10,7 @@ import { ChatHeader } from "@/features/chat/ui/ChatHeader";
 import {
   channelsQueryKey,
   useCreateChannelMutation,
+  useHideDmMutation,
   useOpenDmMutation,
   useChannelsQuery,
   useSelectedChannel,
@@ -107,6 +108,7 @@ export function AppShell() {
   const createChannelMutation = useCreateChannelMutation();
   const createForumMutation = useCreateChannelMutation();
   const openDmMutation = useOpenDmMutation();
+  const hideDmMutation = useHideDmMutation();
   const activeChannel = selectedView === "channel" ? selectedChannel : null;
   const activeChannelId = activeChannel?.id ?? null;
   const messagesQuery = useChannelMessagesQuery(activeChannel);
@@ -305,6 +307,23 @@ export function AppShell() {
     [queryClient],
   );
 
+  const handleHideDm = React.useCallback(
+    async (channelId: string) => {
+      try {
+        await hideDmMutation.mutateAsync(channelId);
+      } catch {
+        // Optimistic rollback handled by onError in the mutation hook.
+        return;
+      }
+      if (selectedChannel?.id === channelId) {
+        React.startTransition(() => {
+          setSelectedView("home");
+        });
+      }
+    },
+    [hideDmMutation, selectedChannel?.id],
+  );
+
   const handleOpenSettings = React.useCallback(
     (section: SettingsSection = DEFAULT_SETTINGS_SECTION) => {
       setIsSearchOpen(false);
@@ -576,6 +595,7 @@ export function AppShell() {
                 setIsSearchOpen(true);
                 void refetchChannels();
               }}
+              onHideDm={handleHideDm}
               onOpenDm={async ({ pubkeys }) => {
                 const directMessage = await openDmMutation.mutateAsync({
                   pubkeys,