diff --git a/docs/systems/dm-system.md b/docs/systems/dm-system.md
index 543bac3a..2f8c57f4 100644
--- a/docs/systems/dm-system.md
+++ b/docs/systems/dm-system.md
@@ -164,7 +164,7 @@ This ensures closed DMs resurface automatically when new activity occurs.
 Close and reopen are relayed to all peer instances that hold a copy of the DM:
 
 - **Close relay:** After setting `closed = 1` locally, `queueDmCloseRelay(channelId, userId, 'dm_close')` queues a `dm_close` outbox event. The receiving instance finds the channel by `federatedId`, resolves the acting user via `resolveLocalUser`, sets `closed = 1` on the local `dm_members` row, and broadcasts `dm_channel_closed`.
-- **Reopen relay:** Explicit reopens (`POST /api/dm/:id/reopen`) queue a `dm_reopen` event. The receiving instance sets `closed = 0` and broadcasts `dm_channel_created` with a full channel payload.
+- **Reopen relay:** Explicit reopens (`POST /api/dm` when reopening a closed 1-on-1 DM) queue a `dm_reopen` event. The receiving instance sets `closed = 0` and broadcasts `dm_channel_created` with a full channel payload.
 - **Relayed-message reopen:** `processCreateEvent` (inbound message relay) also checks each recipient's `closed` flag and performs the same resurface sequence (`dm_channel_created` → `dm_message_created`) — mirroring `broadcastDmMessage`. This ensures messages relayed from a remote instance properly reopen closed DMs on the receiving instance.
 - Only fires for DMs with a `federatedId`. Legacy local-only DMs (no `federatedId`) are unaffected.
 
diff --git a/docs/systems/federation.md b/docs/systems/federation.md
index e5b46885..498bcb86 100644
--- a/docs/systems/federation.md
+++ b/docs/systems/federation.md
@@ -688,7 +688,7 @@ Only DMs with a `federatedId` are eligible. Legacy local-only DMs (created befor
 | Event | Trigger |
 |-------|---------|
 | `dm_close` | User calls `DELETE /api/dm/:id` (soft-close) |
-| `dm_reopen` | User calls `POST /api/dm/:id/reopen` (explicit reopen) |
+| `dm_reopen` | User calls `POST /api/dm` and reopens a closed 1-on-1 DM |
 
 ### Payload
 
@@ -697,7 +697,7 @@ Only DMs with a `federatedId` are eligible. Legacy local-only DMs (created befor
   eventType: 'dm_close' | 'dm_reopen',
   dmChannelId: string,          // local channel ID (context only)
   federatedId: string,          // cross-instance channel lookup key
-  messageId: string,            // unique event ID: 'dm_close:{userId}:{ts}' or 'dm_reopen:{userId}:{ts}'
+  messageId: string,            // unique event ID: 'dm_close:{federatedId}:{userId}:{ts}'
   encryptionVersion: 0,
   timestamp: number,
   dmCloseReopen: {