We often think APIs need frameworks — express(), @RestController, GraphQL, etc. I thought the same when I first saw the Model Context Protocol (MCP) used by tools like Copilot and Claude.
But I couldn’t grasp it by reading libraries. So I tried building an MCP server from scratch — in Bash.
That led me to discover JSON-RPC, a protocol that’s surprisingly minimal and elegant.
In this talk, I’ll walk through that journey — understanding stdio vs CLI, decoding JSON-RPC basics, and how removing layers of abstraction helped me see what’s really happening.
This isn’t about Bash. It’s about learning protocols by building them — something you can do in JS, Go, Python, or anything once you get the idea.
What JSON-RPC really is — without frameworks
How stdio app is different from command line app
What MCP is and how tools like Copilot/Claude use it
Why writing from scratch (even in Bash) helps understand better
How you can build your own MCP server in any language
This is a good from the ground up project that many people who would find relatable and helpful.
More people need to dabble on the command line