How the Debug Adapter Protocol (DAP) Can Double as a REPL

What if your debugger could secretly be a REPL? This video reveals how the Debug Adapter Protocol, DAP, can be repurposed as an interactive Read Eval Print Loop, and why that hack is surprisingly powerful and practical. Watch the demo to see the evaluate request return a variables reference, then cash that ticket in with a variables request to inspect complex objects layer by layer. This video has been generated automatically by AutoContent API - https://autocontentapi.com

Key takeaways:
DAP was designed to standardize editor to debugger communication, but it already includes the building blocks of a REPL, like evaluate, result text, and variables inspection.
The variablesReference number is the secret ticket that lets you drill into complex data, enabling nested inspection just like a real debugger.
The main benefit is practical efficiency, reuse, and a polished UI without rebuilding a new interface, a case of "clever laziness."
The tradeoffs are boilerplate and pretending to be a debugger, for example handling session setup, dummy launch requests, and cleanup to satisfy the DAP spec.

If you found this idea surprising or useful, please like and subscribe for more engineering hacks. Tell us in the comments which tools you think might have hidden superpowers, or share your own DAP REPL experiments. Want a follow up? Say whether you want a walkthrough of implementing the evaluate/variables flow, or a demo in a specific language. Thanks for watching, and thanks to everyone on the call!