I built a native WebSocket & MQTT client for Excel VBA (Zero DLLs, streams live data without freezing)

The struggle of streaming live data into Excel with VBA is a common pain point—XMLHTTP calls that freeze the UI, polling loops that tax resources, or a reliance on external DLLs that corporate IT blocks. The new Wasabi module tackles this head‑on by offering a single, zero‑dependency .bas file that delivers full‑blown WebSocket (WSS) and MQTT support right inside the VBA editor. For developers who have experimented with real‑time dashboards, cryptocurrency tickers, or even multiplayer games built in PowerPoint, this is a direct hit to a long‑standing bottleneck. As a bonus, the same tool powers the hidden‑sheet Discord bot project detailed in “I made a Discord bot that runs from a hidden Excel sheet. Because why not.” /post/i-made-a-discord-bot-that-runs-from-a-hidden-excel-sheet-bec-cmox80k3y0g9vjfqb01cledc1, showing that Wasabi’s reach extends beyond traditional spreadsheet use cases.

Wasabi’s design is refreshingly simple: a single .bas module that can be imported straight from the VBA editor. No references, no DLL registration, no extra libraries to manage. It works across 32‑bit and 64‑bit Office, from legacy Windows XP clients to the latest Windows 11 machines. The module uses Windows Schannel to negotiate TLS, so secure WebSocket connections (wss://) are as straightforward as a normal HTTP request. Corporate environments that enforce proxy authentication—NTLM or Kerberos—are accommodated out of the box, removing a common deployment hurdle that often forces teams to settle for less secure or less performant solutions. The result is a tool that feels like an extension of Excel itself, rather than an external add‑in that requires IT approval.

The real power of Wasabi lies in its application. By exposing a clean, event‑driven API, developers can stream data from any WebSocket‑enabled source—think Binance or Coinbase live quotes—directly into cells with millisecond latency. The built‑in MQTT 3.1.1 client opens a new frontier for connecting Excel to IoT brokers such as Mosquitto, enabling industrial dashboards that update in real time without the need for custom middleware or additional software. For teams building dashboards that must react instantly to market changes or sensor feeds, this eliminates the “freeze‑and‑wait” pattern that has long plagued VBA solutions. Moreover, because Wasabi is a pure VBA module, it can be version‑controlled, reviewed, and shared with the same rigor that modern software teams expect, all while staying within the familiar VBA ecosystem.

The community response to Wasabi reinforces its value. Stars from respected low‑level VBA developers like wqweto, Maatooh, and EagleAglow—who have adopted it in their own repositories—signal that the tool is not just a novelty but a practical, battle‑tested solution. The project’s documentation, including an API reference and architectural overview, is readily available on GitHub, making onboarding fast and transparent. For developers who have tried to add real‑time capabilities to an Excel project and found the built‑in options lacking, Wasabi offers a compelling alternative that reduces complexity while expanding functionality.

Looking ahead, the implications of a native, zero‑dependency WebSocket and MQTT stack for Excel are significant. As data sources become increasingly real‑time and distributed—think edge computing, smart factories, or decentralized finance—Excel’s role as a ubiquitous analytics tool could be revitalized. By removing the friction of external dependencies and corporate IT gatekeepers, Wasabi empowers a broader range of users to build responsive, data‑driven solutions directly within spreadsheets. The question for the community now is: how will developers extend this foundation to create higher‑level abstractions, such as reactive cell formulas or visual dashboards that automatically adjust to incoming streams? The next wave of innovation may well come from those who take Wasabi as a starting point and build the next generation of real‑time analytics directly inside Excel.