lnk3 · Aug 24, 2026 · lnk3 · Aug 24, 2026 · lnk3 · Aug 24, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -5,6 +5,7 @@
 ### Features
 
 - Add support for `buildNpmPackage`
+- Add support for `buildNimPackage`
 
 ## v0.3.6 - 2026-05-15
 

diff --git a/README.md b/README.md
@@ -73,6 +73,7 @@ Options:
 - `buildPythonApplication` and `buildPythonPackage`
 - `buildGoModule`
 - `buildNpmPackage`
+- `buildNimPackage`
 
 ### Supported fetchers
 

diff --git a/src/cli.rs b/src/cli.rs
@@ -75,6 +75,7 @@ pub struct Opts {
 pub enum BuilderFunction {
     BuildGoModule,
     BuildNpmPackage,
+    BuildNimPackage,
     BuildPythonApplication,
     BuildPythonPackage,
     BuildRustPackage,

diff --git a/src/codegen/mod.rs b/src/codegen/mod.rs
@@ -1,5 +1,6 @@
 pub mod drv;
 pub mod go;
+pub mod nim;
 pub mod npm;
 pub mod python;
 pub mod rust;
@@ -26,8 +27,8 @@ use tracing::warn;
 use crate::{
     cli::CargoVendor,
     codegen::{
-        drv::MkDerivation, go::BuildGoModule, npm::BuildNpmPackage, python::BuildPythonPackage,
-        rust::BuildRustPackage,
+        drv::MkDerivation, go::BuildGoModule, nim::BuildNimPackage, npm::BuildNpmPackage,
+        python::BuildPythonPackage, rust::BuildRustPackage,
     },
     frontend::FrontendDispatch,
     inputs::{AllInputs, write_all_lambda_inputs, write_inputs, write_lambda_input},
@@ -44,6 +45,7 @@ use crate::{
 #[display("{0}")]
 pub enum BuilderDispatch {
     BuildGoModule(BuildGoModule),
+    BuildNimPackage(BuildNimPackage),
     BuildNpmPackage(BuildNpmPackage),
     BuildPythonPackage(BuildPythonPackage),
     BuildRustPackage(BuildRustPackage),
@@ -80,6 +82,7 @@ pub struct SourceLayout {
     pub has_cmake: bool,
     pub has_go: bool,
     pub has_meson: bool,
+    pub has_nim: bool,
     pub has_npm: bool,
     pub has_npm_lock: bool,
     pub has_python: bool,
@@ -474,6 +477,10 @@ impl SourceLayout {
             has_cmake: src_dir.join("CMakeLists.txt").is_file(),
             has_go: src_dir.join("go.mod").is_file(),
             has_meson: src_dir.join("meson.build").is_file(),
+            has_nim: std::fs::read_dir(src_dir).is_ok_and(|dir| {
+                dir.filter_map(Result::ok)
+                    .any(|entry| entry.path().extension().is_some_and(|ext| ext == "nimble"))
+            }),
             has_npm: src_dir.join("package.json").is_file(),
             has_npm_lock: src_dir.join("package-lock.json").is_file()
                 || src_dir.join("npm-shrinkwrap.json").is_file(),

diff --git a/src/codegen/nim.rs b/src/codegen/nim.rs
@@ -0,0 +1,59 @@
+use std::{
+    fmt::Write as _,
+    path::{Path, PathBuf},
+};
+
+use anyhow::Result;
+use parse_display::Display;
+
+use crate::codegen::{Builder, Codegen};
+
+#[derive(Clone, Copy, Display)]
+#[display("buildNimPackage")]
+pub struct BuildNimPackage;
+
+impl Builder for BuildNimPackage {
+    fn function(&self) -> &'static str {
+        "buildNimPackage"

10000
+    }
+
+    fn explicit_strict_deps(&self) -> bool {
+        true
+    }
+
+    async fn after_src(&self, cg: &mut Codegen<'_>) -> Result<String> {
+        let mut out = String::new();
+
+        let lock_path = get_lock_path(cg.out_dir);
+
+        writeln!(
+            out,
+            "  # Generate lockfile with: nix run -f . nim_lk ./result | jq --sort-keys > {lock_path}"
+        )?;
+        writeln!(out, "  lockFile = ./lock.json;\n")?;
+
+        if let Some(file) = find_nimble_file(cg.src_dir) {
+            writeln!(out, "  nimbleFile = \"{file}\";\n")?;
+        }
+
+        writeln!(out, "  nimFlags = [ ];\n")?;
+
+        Ok(out)
+    }
+}
+
+fn get_lock_path(out_dir: Option<&Path>) -> String {
+    out_dir
+        .map(|d| d.join("lock.json"))
+        .unwrap_or_else(|| PathBuf::from("lock.json"))
+        .display()
+        .to_string()
+}
+
+fn find_nimble_file(src_dir: &Path) -> Option<String> {
+    std::fs::read_dir(src_dir)
+        .ok()?
+        .filter_map(Result::ok)
+        .find(|entry| entry.path().extension().is_some_and(|ext| ext == "nimble"))
+        .map(|entry| entry.file_name().to_string_lossy().into_owned())
+}
diff --git a/src/main.rs b/src/main.rs
@@ -40,7 +40,8 @@ use crate::{
     cmd::{NIX, NURL},
     codegen::{
        BuilderDispatch, Codegen, SourceLayout, drv::MkDerivation, go::BuildGoModule,
-        npm::BuildNpmPackage, python::BuildPythonPackage, rust::BuildRustPackage,
+        nim::BuildNimPackage, npm::BuildNpmPackage, python::BuildPythonPackage,
+        rust::BuildRustPackage,
     },
     fetcher::{Fetcher, FetcherDispatch, PackageInfo, PypiFormat, Revisions, Version},
     frontend::{Frontend, headless, readline},
@@ -385,6 +386,7 @@ async fn run() -> Result<()> {
     let builder = match (opts.builder, opts.cargo_vendor) {
         (Some(builder), rust @ Some(vendor)) if layout.has_cargo => match builder {
             BuilderFunction::BuildGoModule => BuildGoModule.into(),
+            BuilderFunction::BuildNimPackage => BuildNimPackage.into(),
             BuilderFunction::BuildNpmPackage => BuildNpmPackage.into(),
             BuilderFunction::BuildPythonApplication => BuildPythonPackage::new(true, rust).into(),
             BuilderFunction::BuildPythonPackage => BuildPythonPackage::new(false, rust).into(),
@@ -396,6 +398,7 @@ async fn run() -> Result<()> {
             let rust = layout.has_cargo.then_some(CargoVendor::FetchCargoVendor);
             match builder {
                 BuilderFunction::BuildGoModule => BuildGoModule.into(),
+                BuilderFunction::BuildNimPackage => BuildNimPackage.into(),
                 BuilderFunction::BuildNpmPackage => BuildNpmPackage.into(),
                 BuilderFunction::BuildPythonApplication => {
                     BuildPythonPackage::new(true, rust).into()
@@ -414,6 +417,10 @@ async fn run() -> Result<()> {
                 builders.push(BuildGoModule.into());
             }
 
+            if layout.has_nim {
+                builders.push(BuildNimPackage.into());
+            }
+
             if layout.has_cargo {
                 let cargo_deps_options: &[_] = match rust {
                     Some(vendor) => &[vendor],

diff --git a/tests/cmd/nim.out/default.nix b/tests/cmd/nim.out/default.nix
@@ -0,0 +1,38 @@
+{
+  lib,
+  buildNimPackage,
+  fetchFromGitHub,
+  nix-update-script,
+}:
+
+buildNimPackage (finalAttrs: {
+  pname = "choosenim";
+  version = "0.8.16";
+  __structuredAttrs = true;
+  strictDeps = true;
+
+  src = fetchFromGitHub {
+    owner = "nim-lang";
+    repo = "choosenim";
+    tag = "v${finalAttrs.version}";
+    hash = "sha256-Sa1T7uZDIZHsakyI7QeJEWrHW7rSarFDniY9FaTBL7Q=";
+  };
+
+  # Generate lockfile with: nix run -f . nim_lk ./result | jq --sort-keys > ./lock.json
+  lockFile = ./lock.json;
+
+  nimbleFile = "choosenim.nimble";
+
+  nimFlags = [ ];
+
+  passthru.updateScript = nix-update-script { };
+
+  meta = {
+    description = "Official tool for easily installing and managing multiple versions of the Nim programming language";
+    homepage = "https://github.com/nim-lang/choosenim";
+    changelog = "https://github.com/nim-lang/choosenim/blob/${finalAttrs.src.rev}/changelog.markdown";
+    license = lib.licenses.bsd3;
+    maintainers = with lib.maintainers; [ alice ];
+    mainProgram = "choosenim";
+  };
+})
diff --git a/tests/cmd/nim.toml b/tests/cmd/nim.toml
@@ -0,0 +1,5 @@
+args = [
+  "--headless",
+  "--url=https://github.com/nim-lang/choosenim",
+  "--rev=v0.8.16",
+]