Web API Extension

Inspiration

Working with a specific SaaS and API (fintech), that is planned to be phased out. While both the SaaS and API are not directly supported anymore, and new tech like WebMCP are unlikely to be added -- they are still used daily by hundreds of thousands of merchants across the world.

What if that B2B SaaS could support WebMCP without the vendor needing to make any changes? A WebMCP browser extension could uplift it to the latest tech, until the next version - possibly years away - supports WebMCP natively.

What it does

The product is a browser framework that uplifts a legacy SaaS to support WebMCP, even if the SaaS itself does not expose tools to the agent. The browser extension jumps in. It provides full context to the agent: backend power plus browser tab content.

How we built it

An existing, battle proven MCP server was converted into a Chrome extension, features added (BYOK chat, telemetry/security chokepoint, sandboxed code execution, many others), and the concept was then used to architect an extension development framework for future browser extensions that will provide the same benefit to other SaaS that need uplifting.

Challenges we ran into

Basic model: a bit weak on the reasoning front, needs guidance. Advanced model: too much reasoning, needs guidance. Interesting problem to have!

Accomplishments that we're proud of

The showcase extension, covering one specific B2B SaaS, was presented to a future user. They confirmed that it would be useful.

What's next for Web API Extension

The showcase extension has been released for UAT usage (private link in the web store as it's tailored to one SaaS). The showcase extension has now been abstracted to become a browser extension framework. This framework needs development. Also: Extending the framework to involve other emerging tech such as MCP-B or in-browser models.

Built With

• chrome.storage
• code-mode-sandbox
• eslint
• extension.js-v2.1.3-targeting-manifest-v3
• javascript
• node.js
• npm
• postcss
• prettier
• react
• tailwind
• typescript
• utcp
• vitest
• webmcp
• zod