Frequently Asked Questions

Q: What's the relationship between BSP and LSP?

A: They are complementary protocols. While LSP specifies endpoints for communication between an editor acting as client and language server, BSP specifies endpoints between a language server acting as client and build server. For example, in order to respond to a textDocument/definition request from an editor client, a language server could query a build tool via BSP for the classpath of a module.

Q: What's the relationship between implementations of BSP and implementations of LSP like dragos/dragos-vscode-scala, Dotty IDE or Metals?

A: Currently, those language servers each implement custom integrations for each supported build tool to extract build metadata. Those language servers could instead implement a BSP client to extract build metadata from any build tools that implement BSP, sharing a single BSP server implementation. Likewise, a new build tool could implement a BSP server and support a wide range of language servers out-of-the-box.