u

src/providers/mssql/queries/modelconversation.js

@@ -5,15 +5,25 @@ export const MODELCONVERSATION_COLUMNS = `
     model,
     created_at,
     updated_at,
-    state
+    state,
+    started_by
 `;
 
 export const LIST_BY_COMPANYUSER = `
 SELECT
-${MODELCONVERSATION_COLUMNS}
-FROM modelconversation
-WHERE companyuser_id = @companyuserId
-ORDER BY updated_at DESC, id DESC
+${MODELCONVERSATION_COLUMNS},
+    (
+        SELECT m.message
+        FROM modelmessage m
+        WHERE m.id = (
+            SELECT MIN(f.id)
+            FROM modelmessage f
+            WHERE f.conversation_id = c.id AND f.role = 'user'
+        )
+    ) AS first_user_message
+FROM modelconversation c
+WHERE c.companyuser_id = @companyuserId
+ORDER BY c.updated_at DESC, c.id DESC
 `;
 
 export const GET_BY_COMPANYUSER_AND_ID = `
@@ -27,7 +37,8 @@ export const CREATE = `
 INSERT INTO modelconversation (
     companyuser_id,
     provider,
-    model
+    model,
+    started_by
 )
 OUTPUT
     INSERTED.id,
@@ -36,11 +47,13 @@ OUTPUT
     INSERTED.model,
     INSERTED.created_at,
     INSERTED.updated_at,
-    INSERTED.state
+    INSERTED.state,
+    INSERTED.started_by
 VALUES (
     @companyuserId,
     @provider,
-    @model
+    @model,
+    @startedBy
 )
 `;
 
@@ -69,11 +82,30 @@ OUTPUT
     INSERTED.model,
     INSERTED.created_at,
     INSERTED.updated_at,
-    INSERTED.state
+    INSERTED.state,
+    INSERTED.started_by
 WHERE id = @id AND companyuser_id = @companyuserId
 `;
 
+/**
+ * Deletes a conversation and, because started_by is not a foreign key, the whole chain of
+ * subagent conversations below it (started_by -> id, recursively) in a single statement.
+ * Messages go with their conversations via ON DELETE CASCADE. rowsAffected is 0 only when
+ * the root conversation does not exist for this user (a root always yields >= 1 row).
+ */
 export const DELETE_BY_COMPANYUSER_AND_ID = `
+WITH subtree AS (
+    SELECT id
+    FROM modelconversation
+    WHERE id = @id AND companyuser_id = @companyuserId
+
+    UNION ALL
+
+    SELECT c.id
+    FROM modelconversation c
+    INNER JOIN subtree s ON c.started_by = s.id
+    WHERE c.companyuser_id = @companyuserId
+)
 DELETE FROM modelconversation
-WHERE id = @id AND companyuser_id = @companyuserId
+WHERE id IN (SELECT id FROM subtree)
 `;

src/providers/mssql/schema.js

@@ -819,10 +819,12 @@ BEGIN
         created_at DATETIME2 NOT NULL CONSTRAINT DF_modelconversation_created_at DEFAULT SYSUTCDATETIME(),
         updated_at DATETIME2 NOT NULL CONSTRAINT DF_modelconversation_updated_at DEFAULT SYSUTCDATETIME(),
         state NVARCHAR(20) NOT NULL CONSTRAINT DF_modelconversation_state DEFAULT 'idle',
+        started_by INT NULL, -- id of the conversation that started this one as a subagent; deliberately NOT a foreign key
         CONSTRAINT FK_modelconversation_companyuser FOREIGN KEY (companyuser_id) REFERENCES companyuser(id) ON DELETE CASCADE,
         CONSTRAINT CK_modelconversation_state CHECK (state IN ('idle', 'busy'))
     );
     CREATE INDEX IX_modelconversation_companyuser ON modelconversation (companyuser_id, updated_at);
+    CREATE INDEX IX_modelconversation_started_by ON modelconversation (started_by);
 END
 `;