Raven
Raven is a language server for R, with additional support for Stan and JAGS. Its defining idea: what's in scope depends on where your cursor is. Raven traces source() chains and resolves scope at your position, so completions, diagnostics, and navigation reflect what's actually defined when each line runs — across files, and within a single script (a variable defined on line 50 isn't in scope on line 10).
Because scope is resolved by position, Raven can flag genuinely undefined variables — and, parsing as you type, it catches parse errors (unclosed brackets, an else stranded from its }) and likely-bug patterns like mixed logical operators (a & b | c).
vscode-R (REditorSupport's R extension) is the established R extension for VS Code; Raven's language server runs alongside it, contributing cross-file, scope-aware code intelligence (plus configurable syntax-aware indentation) on top of what you already have.
vscode-R's language intelligence comes from r-language-server, an R package that runs inside an R session and indexes the documents you have open (and, in an R package, its R/ directory). Raven is written in Rust to be fast, and needs no R session: it indexes your whole workspace and follows source() chains, so completions and navigation reach symbols in files you haven't opened — jump straight to a variable's definition in another file.
Raven is designed to complement, not replace, your existing tools. But it can run without vscode-R installed, if you want: then Raven uses its own R console, with data and plot viewers. Otherwise — if vscode-R is installed, or you're running inside Positron — those features stay off by default; they simply don't appear, so Raven leaves your existing setup untouched.
Features
Code intelligence
- Completions — Symbols, packages, and function parameters — across files
- Go-to-definition — Jump to definitions across file boundaries
- Find references — Locate all usages of a symbol across your project
- Hover — Symbol info including source file and package origin
- Diagnostics — Undefined variable detection that understands sourced files and loaded packages, plus opt-in style/lint rules
- Document outline — Hierarchical view with sections, classes, and nested functions
- Workspace symbols — Project-wide symbol search (Cmd/Ctrl+T)
- File path intellisense — Completions and cmd-click inside
source() paths
- Smart indentation — Context-aware auto-indent with configurable argument and chain styles
- Cross-file awareness — Follows
source() chains to resolve scope across files
- Directives — Declare relationships and symbols the analyzer can't infer
- Syntax highlighting — R function names via LSP semantic tokens, plus JAGS and Stan syntax highlighting
Raven's R diagnostics include scope-aware findings and tailored explanations. Its cross-file scope model follows source() chains, .Rprofile, supported package attachment and import forms, static {targets} / {tarchetypes} patterns, and testthat/testit/Shiny conventions.
Raven also supports JAGS (.jags, .bugs, .bug) and Stan (.stan) files with syntax highlighting, completions, hover, syntax diagnostics, go-to-definition, find references, and model-structure outlines. JAGS additionally provides static signature help for built-ins, while Stan provides conservative undeclared-variable diagnostics.
R session integration
- R console — Interactive R console with statement detection and a temp-file fallback for large blocks; supports R, arf, and radian
- Code chunks — R Markdown / Quarto chunk detection with Run Chunk / Run Above / Run All commands, CodeLens buttons, navigation, and background highlighting;
# %% cell support in .R files
- Knit Preview + Export —
Raven: Knit Preview renders R Markdown to an HTML preview without requiring Pandoc; companion Export to HTML / PDF / Word commands save the result next to the .Rmd via Pandoc
- Plot viewer — Plots render in a VS Code panel via httpgd, with history navigation, save (PNG/SVG/PDF), and theme-aware background
- Data viewer —
View(df) opens a virtualized grid backed by Apache Arrow; viewport-based rendering keeps scrolling responsive on multi-million-row frames
- Help viewer — Scope-aware R help: hovering shows the function in scope at the cursor instead of falling through to a multi-package list when scope can't be inferred
Settings
All settings live under the raven.* prefix. See the full configuration reference for the complete list.
Coexistence with vscode-R and Positron
Raven's R-console features (R console, plot viewer, data viewer) and vscode-R cover overlapping ground. By default raven.rConsole.activation is "auto", which leaves Raven's R-console features off when vscode-R is enabled or you're running inside Positron. Raven's help viewer and language server activate either way.
Raven ships its own opt-in style linter — a subset of lintr's rules re-implemented natively, with no R session or lintr install required. For lintr rules outside that subset, vscode-R's lintr diagnostics run from its own language server.
Two vscode-R settings (both default to true) let you trim that overlap:
r.lsp.diagnostics — set to false to silence lintr while keeping vscode-R's session-based completions.r.lsp.enabled — set to false to shut vscode-R's language server down entirely. Use this when you only want vscode-R for its R-session features (console, viewers) and are happy to let Raven handle all code intelligence.
"r.lsp.diagnostics": false, // keep vscode-R's LSP, drop only its lintr diagnostics
"r.lsp.enabled": false // or: disable vscode-R's LSP entirely
For a deeper comparison see docs/comparison.md.
See the main repository for full documentation, including running the same analysis in CI with raven check, cross-file directives, editor integrations, and comparison with other R tools.
If you work with Stata, see Raven's sibling project, Sight, a Stata language server with the same cross-file awareness model.
License
GPL-3.0
