// the find
expert-lsp/expert
Official Elixir Language Server Protocol implementation
Expert is the official Elixir Language Server, positioned as the eventual successor to ElixirLS, built by core Elixir Language Server Foundation (EEF) sponsors. It's for any Elixir developer who wants IDE features (completion, hover, go-to-definition, code actions) in their editor, but it's explicitly alpha software with no 1.0 release yet.
The architecture splits a protocol-handling app (expert) from an analysis engine (engine) that runs in its own isolated node and actually compiles the project rather than just parsing syntax — that matters in Elixir where macros make static-only analysis unreliable. It ships real code actions (create undefined function, organize/remove aliases, replace remote function calls) instead of just completion and hover. Engineering hygiene is solid: dependabot, release-please for changelog automation, zizmor for GitHub Actions security linting, and a real test suite covering the analyzer, indexer extractors, and code mod diffing.
It's alpha with no stable release — the README itself links out to a milestones page instead of a changelog of what actually works today. Building from source pins Zig to exactly 0.15.2 for the burrito cross-platform build ('later versions will not work'), which is a brittle toolchain dependency likely to rot. Because analysis runs through a real compile of your project in a separate engine node, startup and memory cost on larger codebases is an open question the README doesn't address at all — no benchmarks, no comparison to ElixirLS's resource usage. There's also no in-README feature matrix or migration note for people currently on ElixirLS, so evaluating whether to switch means reading external docs first.