Lightstreamer Workbench

Inspect Lightstreamer activity and test Item Updates or Client Messages in Chrome DevTools.

New in 2.0.7: COMMAND Clear and exact key handling are more reliable, and long sessions release discarded runtime objects and bound historical bookkeeping. With companion 0.1.5, agents can read one exact COMMAND key with certainty and provenance, wait for an existing operation without repeating it, and recover from incompatible companion versions. MCP reads preserve JSON values, support cancellation, and keep replies within explicit budgets. Lightstreamer Workbench adds a Chrome DevTools panel for applications that use the official Lightstreamer Web Client. It captures clients, Sessions, Subscriptions, listeners, Item Updates, snapshots, and COMMAND key lifecycles. The workspace has Runtime Scope, Ordered Evidence, and Context. Key features: - Select the page, client, Session, Subscription, item, or listener in Runtime Scope. You can inspect retired objects, but you cannot use them as Local Injection targets. - Read compact operation codes, complete single-line keys, and captured data in retained order. Op stays pinned while keys and data scroll horizontally. Open Codes for the Lightstreamer and Workbench lifecycle reference. - Read JSON string fields in a clearly marked readable view, or use Raw fields to preserve captured types. Complete data and exact event metadata remain in Context. - Use a consistent Off / Include / Exclude control for Evidence and notification filters. Workbench uses dark mode in every system appearance. - Use Find, Filter, selection, Capture, Coverage, and Live or Frozen independently. - Select an event to inspect its Fields, raw Evidence, Source, COMMAND details, and limits in Context. - Capture outbound Client Messages and their normal listener outcomes as ordered Evidence. - Review active conditions and recent Lightstreamer diagnostics in Notifications. Dismiss hides only the footer message. - Trace COMMAND `ADD`, `UPDATE`, and `DELETE` operations. Use Fields, diagnostics, and Checkpoints for more detail. - Create one protected Local Injection Draft from captured Evidence or from a live COMMAND Scope. - Edit raw JSON and validate the Draft. Captured Drafts compare Source and Draft by default, then inject directly from that preview. - Use a Local Injection Scenario for ordered Steps, immutable reviewed Runs, serial controls, Checkpoints, and results for each Step. - Connect a local MCP companion to inspect a Panel Session's Scope, Evidence, diagnostics, and Local Injection Scenario results. Agents can profile and query streams, validate candidates, prepare Scenarios, and inspect Scenario traces. They cannot perform Server Injection, clear Event History, or evaluate arbitrary page code. - When a panel opens, Agent access is on by default with inspection and Local Injection available together. There is no read-only mode. The header shows On, Waiting, or Off and opens the access control under More actions → Agent access and setup. Authentication is off; any local process that can reach the companion can use the connected panel's grant. Run Chrome and the Node.js 22.12+ companion on the same computer. - Deliver an Item Update to the exact live Subscription in the inspected page. Workbench reports delivered, failed, partial, unknown, and stale-target results. - Create a protected Server Injection Draft from captured Client Message Evidence, author one for an exact live client and Session, or start from an application-owned Message Recipe. - Review every LightstreamerClient.sendMessage argument, then send the Client Message once through the inspected application's normal client-to-server path. - Treat Processed as a Lightstreamer message outcome, not proof of an application business effect or later Server Update. Workbench never retries an Unknown outcome automatically. - Use WebSocket/TLCP fallback diagnostics when the primary Web Client instrumentation is not available. - Keep one temporary Event History for each Panel Session. IndexedDB can keep 100,000 records or 256 MiB. The memory fallback can keep 25,000 records or 128 MiB. - Use the Committed Evidence Boundary to find the end of complete History. Retention removes the oldest accepted prefix while Capture continues and reports the Retention Advance. An Evidence Gap means captured activity could not be accepted into Event History. - A controlled Close tries to erase Event History. An abnormal stop can leave residual data until Chrome runs the extension again. A new Panel Session starts empty. - Configured production builds use usage analytics for fixed feature names, engagement time, coarse outcomes, and a random installation identifier. It is on by default and can be turned off in More actions → Help & resources → Usage analytics. Captured Evidence and typed text are excluded from analytics; separate Agent access can send requested Evidence to a local MCP client and its configured model provider. - No advertising, account sign-in, or maintainer-operated collection backend. - Help links open the project documentation, privacy policy, and support page. Use this extension to inspect and test Lightstreamer behavior in Chrome DevTools.