diff --git a/packages/http-routes/src/routes/shared-routes.test.ts b/packages/http-routes/src/routes/shared-routes.test.ts
index a750b60e..cc4a970e 100644
--- a/packages/http-routes/src/routes/shared-routes.test.ts
+++ b/packages/http-routes/src/routes/shared-routes.test.ts
@@ -262,6 +262,33 @@ describe('registerSharedRoutes smoke tests', () => {
     assert.equal(countRow.count, 3)
   })
 
+  it('POST /_web/sessions/:id/sql returns rows in the SQL Lab columnar shape', async () => {
+    const db = createSessionDb()
+    const routeApp = Fastify()
+    registerSharedRoutes(routeApp, createTestContext(new Map([['chat-1', db]])))
+    await routeApp.ready()
+
+    const resp = await routeApp.inject({
+      method: 'POST',
+      url: '/_web/sessions/chat-1/sql',
+      payload: { sql: 'SELECT id, content FROM message ORDER BY id LIMIT 2' },
+    })
+
+    await routeApp.close()
+    db.close()
+
+    assert.equal(resp.statusCode, 200)
+    const body = resp.json()
+    assert.deepEqual(body.columns, ['id', 'content'])
+    assert.deepEqual(body.rows, [
+      [1, 'alpha first'],
+      [2, 'alpha from bob'],
+    ])
+    assert.equal(body.rowCount, 2)
+    assert.equal(body.limited, false)
+    assert.equal(typeof body.duration, 'number')
+  })
+
   it('PATCH /_web/sessions/:id/name updates the shared session metadata', async () => {
     const db = createSessionDb()
     const routeApp = Fastify()
diff --git a/packages/http-routes/src/routes/web/sql.ts b/packages/http-routes/src/routes/web/sql.ts
index 679cf5a7..3b70bd68 100644
--- a/packages/http-routes/src/routes/web/sql.ts
+++ b/packages/http-routes/src/routes/web/sql.ts
@@ -12,7 +12,14 @@ export function registerSqlRoutes(server: FastifyInstance, ctx: HttpRouteContext
       return reply.code(400).send({ error: 'Missing sql parameter' })
     }
     try {
-      return executeSql(db, sql, { timing: true })
+      const result = executeSql(db, sql, { columnar: true, timing: true, maxRows: 0 })
+      return {
+        columns: result.columns,
+        rows: result.rows,
+        rowCount: result.rowCount,
+        duration: result.duration ?? 0,
+        limited: result.truncated,
+      }
     } catch (err: unknown) {
       const message = err instanceof Error ? err.message : 'SQL execution error'
       return reply.code(400).send({ error: message })