Helix LSP

Helix can run Bifrost directly through its built-in language-server configuration. No Bifrost-specific Helix plugin is required.

Put this in ~/.config/helix/languages.toml, start Helix from the workspace root, and open a supported source file:

[language-server.bifrost]
command = "bifrost"
args = ["--root", ".", "--lsp"]

[[language]]
name = "c"
language-servers = ["bifrost"]

[[language]]
name = "cpp"
language-servers = ["bifrost"]

[[language]]
name = "c-sharp"
language-servers = ["bifrost"]

[[language]]
name = "go"
language-servers = ["bifrost"]

[[language]]
name = "java"
language-servers = ["bifrost"]

[[language]]
name = "javascript"
language-servers = ["bifrost"]

[[language]]
name = "jsx"
language-servers = ["bifrost"]

[[language]]
name = "typescript"
language-servers = ["bifrost"]

[[language]]
name = "tsx"
language-servers = ["bifrost"]

[[language]]
name = "php"
language-servers = ["bifrost"]

[[language]]
name = "python"
language-servers = ["bifrost"]

[[language]]
name = "ruby"
language-servers = ["bifrost"]

[[language]]
name = "rust"
language-servers = ["bifrost"]

[[language]]
name = "scala"
language-servers = ["bifrost"]

This assumes bifrost is installed on PATH:

cargo install brokk-bifrost --locked --force

For local development, build this checkout and use an absolute binary path:

cargo build --bin bifrost

Then update the Helix config:

[language-server.bifrost]
command = "/path/to/bifrost/target/debug/bifrost"
args = ["--root", ".", "--lsp"]

[[language]]
name = "java"
language-servers = ["bifrost"]

Add the same language-servers = ["bifrost"] entry for the other languages you want Bifrost to handle.

Workspace Roots

--root is the fallback workspace root. Helix sends the current working directory as rootPath, so args = ["--root", ".", "--lsp"] works when you start Helix from the repository root:

cd /path/to/project
hx src/main/java/example/App.java

If you start Helix outside the project, pass an absolute root instead:

[language-server.bifrost]
command = "bifrost"
args = ["--root", "/path/to/project", "--lsp"]

Helix supports multiple language servers per language. If you want Bifrost to coexist with a language-specific server, include both names in that language’s list:

[[language]]
name = "java"
language-servers = ["bifrost", "jdtls"]

Running multiple servers can be useful when another server provides formatting or diagnostics, but it can also produce duplicate or competing navigation results. Keep the language-servers list to Bifrost alone if you want Bifrost to be the only server Helix uses for that language.

Confirm Bifrost Is Running

Check that Helix can find the configured Bifrost server:

hx --health java

The language server section should list bifrost with a check mark and the command path Helix will run.

To capture startup and request logs, launch Helix with an explicit log file:

hx -vvv --log /tmp/helix-bifrost.log src/main/java/example/App.java

Open a supported file and use Helix’s normal LSP navigation commands, such as gd for go to definition or gr for references. The log should show initialize, textDocument/definition, or textDocument/references messages for bifrost.

For deeper Bifrost-side request timing in Helix’s log, add debug environment variables to the language-server entry:

[language-server.bifrost]
command = "bifrost"
args = ["--root", ".", "--lsp"]
environment = { BIFROST_LSP_DEBUG = "1", BIFROST_LSP_SLOW_MS = "0" }