Version pins

Pins live in linguo.toml, resolved from the nearest file up the directory tree, then the global config (~/.linguo/config.toml):

[runtimes]
python = "3.12"
node = "24"
rust = "1.96"
terraform = "opentofu@1.12"

Pin formats

Requests can be a major (24), minor (3.12), or exact (1.96.1) version. The highest installed match wins.

Rust pins may also be channels: stable, nightly, beta, or dated builds like nightly-2026-07-01. Bare channel pins resolve to the newest installed build of that kind, so activation stays offline and deterministic. linguo rust upgrade is what moves them forward.

Resolution order

When Linguo needs a runtime version, it checks in this order:

1. Project linguo.toml: nearest file walking up the directory tree
2. Ecosystem pin file: when no linguo.toml covers a language:
   • .python-version
   • .nvmrc / .node-version
   • .ruby-version
   • go.mod toolchain / go directives
   • rust-toolchain(.toml)
   • .zigversion
   • build.zig.zon minimum_zig_version
   • .php-version
   • .java-version
3. Global config: ~/.linguo/config.toml

Precedence: project linguo.toml, then the ecosystem pin file, then the global config.

Ecosystem pin files are honored when they hold a plain version (or, for Rust, a channel). Node aliases like lts/* are still ignored.

Toolchain storage

Every download is sha256-verified against its upstream’s published checksums. Toolchains live under:

~/.linguo/toolchains/<language>/<version>

Override the root directory with the $LINGUO_ROOT environment variable.

Existing projects

Existing projects work without a linguo.toml. When none covers a language, Linguo honors the ecosystem’s own pin file as long as it holds a plain version number or Rust channel.

To adopt Linguo explicitly, run linguo <lang> use <version> in your project directory. This writes a linguo.toml with your chosen pin.