diff --git a/lux/lib/lux/rust/cargo_manager.ex b/lux/lib/lux/rust/cargo_manager.ex
new file mode 100644
index 00000000..96ff92ab
--- /dev/null
+++ b/lux/lib/lux/rust/cargo_manager.ex
@@ -0,0 +1,173 @@
+defmodule Lux.Rust.CargoManager do
+  @moduledoc """
+  Cargo package management for Rust in Lux.
+
+  Supports:
+  - Cargo.toml generation and parsing
+  - Dependency add/remove/resolution with semver validation
+  - Build command generation (profile, target, features)
+  - Version management (bump major/minor/patch)
+  - Package cache key generation (SHA256)
+
+  ## Example
+
+      {:ok, toml} = CargoManager.generate_toml(%{name: "my_crate", version: "1.0.0", dependencies: %{serde: "1.0"}})
+      {:ok, parsed} = CargoManager.parse_toml(toml)
+      {:ok, new_ver} = CargoManager.bump_version("1.2.3", :minor)
+  """
+
+  @default_edition "2021"
+
+  @type dep_spec :: String.t() | %{version: String.t(), features: [String.t()]}
+
+  @spec generate_toml(map()) :: {:ok, String.t()} | {:error, atom()}
+  def generate_toml(config) do
+    name = config[:name]
+    version = config[:version] || "0.1.0"
+
+    cond do
+      is_nil(name) or name == "" -> {:error, :missing_name}
+      not semver_valid?(version) -> {:error, :invalid_version}
+      true ->
+        edition = config[:edition] || @default_edition
+        deps = config[:dependencies] || %{}
+
+        toml = """
+        [package]
+        name = "#{name}"
+        version = "#{version}"
+        edition = "#{edition}"
+
+        [dependencies]
+        #{format_deps(deps)}
+        """
+        {:ok, String.trim(toml)}
+    end
+  end
+
+  @spec parse_toml(String.t()) :: {:ok, map()} | {:error, atom()}
+  def parse_toml(content) when is_binary(content) do
+    lines = String.split(content, "\n")
+    {result, _section} = Enum.reduce(lines, {%{}, nil}, fn line, {acc, section} ->
+      line = String.trim(line)
+      cond do
+        String.starts_with?(line, "[") ->
+          section_name = line |> String.trim_leading("[") |> String.trim_trailing("]") |> String.trim()
+          {acc, section_name}
+        String.contains?(line, "=") && section != nil ->
+          [key, val] = String.split(line, "=", parts: 2)
+          key = String.trim(key)
+          val = val |> String.trim() |> String.trim("\"")
+          section_map = Map.get(acc, section, %{})
+          {Map.put(acc, section, Map.put(section_map, key, val)), section}
+        true ->
+          {acc, section}
+      end
+    end)
+    {:ok, result}
+  end
+  def parse_toml(_), do: {:error, :invalid_input}
+
+  @spec add_dependency(map(), atom() | String.t(), String.t(), map()) :: {:ok, map()}
+  def add_dependency(config, name, version, opts \\ %{}) do
+    deps = Map.get(config, :dependencies, %{})
+    dep = Map.merge(%{version: version}, opts)
+    {:ok, Map.put(config, :dependencies, Map.put(deps, name, dep))}
+  end
+
+  @spec remove_dependency(map(), atom() | String.t()) :: {:ok, map()} | {:error, atom()}
+  def remove_dependency(config, name) do
+    deps = Map.get(config, :dependencies, %{})
+    if Map.has_key?(deps, name) do
+      {:ok, Map.put(config, :dependencies, Map.delete(deps, name))}
+    else
+      {:error, :not_found}
+    end
+  end
+
+  @spec resolve_dependencies(map()) :: {:ok, map()} | {:error, map()}
+  def resolve_dependencies(deps) when is_map(deps) do
+    resolved = Enum.map(deps, fn {name, spec} ->
+      version = if is_map(spec), do: spec[:version] || "0.0.0", else: to_string(spec)
+      {name, %{version: version, compatible: semver_valid?(version)}}
+    end)
+    conflicts = Enum.filter(resolved, fn {_n, v} -> !v.compatible end)
+
+    if conflicts == [] do
+      {:ok, %{resolved: Map.new(resolved), conflicts: []}}
+    else
+      {:error, %{conflicts: Enum.map(conflicts, &elem(&1, 0))}}
+    end
+  end
+
+  @spec cache_key(map()) :: {:ok, String.t()}
+  def cache_key(config) do
+    hash = :crypto.hash(:sha256, :erlang.term_to_binary(config))
+           |> Base.encode16(case: :lower)
+           |> binary_part(0, 16)
+    {:ok, hash}
+  end
+
+  @spec build_command(keyword()) :: {:ok, String.t()}
+  def build_command(opts \\ []) do
+    profile = opts[:profile] || :release
+    target = opts[:target]
+    features = opts[:features] || []
+
+    cmd = ["cargo", "build"]
+    cmd = if profile == :release, do: cmd ++ ["--release"], else: cmd
+    cmd = if target, do: cmd ++ ["--target", target], else: cmd
+    cmd = if features != [], do: cmd ++ ["--features", Enum.join(features, ",")], else: cmd
+
+    {:ok, Enum.join(cmd, " ")}
+  end
+
+  @spec bump_version(String.t(), :major | :minor | :patch) :: {:ok, String.t()} | {:error, atom()}
+  def bump_version(version, level \\ :patch) do
+    case String.split(version, ".") do
+      [major, minor, patch] ->
+        with {maj, ""} <- Integer.parse(major),
+             {min, ""} <- Integer.parse(minor),
+             {pat, ""} <- Integer.parse(patch) do
+          new = case level do
+            :major -> "#{maj + 1}.0.0"
+            :minor -> "#{maj}.#{min + 1}.0"
+            :patch -> "#{maj}.#{min}.#{pat + 1}"
+          end
+          {:ok, new}
+        else
+          _ -> {:error, :invalid_version}
+        end
+      _ -> {:error, :invalid_version}
+    end
+  end
+
+  # --- Private ---
+
+  defp format_deps(deps) do
+    Enum.map_join(deps, "\n", fn {name, spec} ->
+      case spec do
+        %{version: v, features: f} ->
+          features = Enum.map_join(f, ", ", &"\"#{&1}\"")
+          "#{name} = { version = \"#{v}\", features = [#{features}] }"
+        %{version: v} -> "#{name} = \"#{v}\""
+        v when is_binary(v) -> "#{name} = \"#{v}\""
+        _ -> "#{name} = \"#{inspect(spec)}\""
+      end
+    end)
+  end
+
+  defp semver_valid?(version) when is_binary(version) do
+    case String.split(version, ".") do
+      [maj, min, pat] ->
+        Enum.all?([maj, min, pat], fn s ->
+          case Integer.parse(s) do
+            {_, ""} -> true
+            _ -> false
+          end
+        end)
+      _ -> false
+    end
+  end
+  defp semver_valid?(_), do: false
+end
diff --git a/lux/test/unit/lux/rust/cargo_manager_test.exs b/lux/test/unit/lux/rust/cargo_manager_test.exs
new file mode 100644
index 00000000..f04bf33d
--- /dev/null
+++ b/lux/test/unit/lux/rust/cargo_manager_test.exs
@@ -0,0 +1,101 @@
+defmodule Lux.Rust.CargoManagerTest do
+  use ExUnit.Case, async: true
+  alias Lux.Rust.CargoManager
+
+  test "generate toml" do
+    {:ok, toml} = CargoManager.generate_toml(%{name: "my_crate", version: "1.0.0", dependencies: %{serde: "1.0", tokio: %{version: "1.0", features: ["full"]}}})
+    assert toml =~ "my_crate"
+    assert toml =~ "1.0.0"
+    assert toml =~ "serde"
+  end
+
+  test "generate toml missing name" do
+    assert {:error, :missing_name} = CargoManager.generate_toml(%{})
+  end
+
+  test "generate toml invalid version" do
+    assert {:error, :invalid_version} = CargoManager.generate_toml(%{name: "x", version: "latest"})
+  end
+
+  test "parse toml" do
+    content = """
+    [package]
+    name = "test"
+    version = "0.1.0"
+
+    [dependencies]
+    serde = "1.0"
+    """
+    {:ok, parsed} = CargoManager.parse_toml(content)
+    assert parsed["package"]["name"] == "test"
+    assert parsed["dependencies"]["serde"] == "1.0"
+  end
+
+  test "parse invalid input" do
+    assert {:error, :invalid_input} = CargoManager.parse_toml(123)
+  end
+
+  test "add dependency" do
+    config = %{dependencies: %{serde: %{version: "1.0"}}}
+    {:ok, updated} = CargoManager.add_dependency(config, :tokio, "1.0", %{features: ["full"]})
+    assert updated.dependencies[:tokio].version == "1.0"
+  end
+
+  test "remove dependency" do
+    config = %{dependencies: %{serde: "1.0", tokio: "1.0"}}
+    {:ok, updated} = CargoManager.remove_dependency(config, :serde)
+    refute Map.has_key?(updated.dependencies, :serde)
+  end
+
+  test "remove dependency not found" do
+    config = %{dependencies: %{serde: "1.0"}}
+    assert {:error, :not_found} = CargoManager.remove_dependency(config, :tokio)
+  end
+
+  test "resolve dependencies" do
+    {:ok, result} = CargoManager.resolve_dependencies(%{serde: %{version: "1.0.0"}, tokio: %{version: "1.28.0"}})
+    assert result.conflicts == []
+    assert result.resolved[:serde].compatible
+  end
+
+  test "resolve with invalid version" do
+    {:error, result} = CargoManager.resolve_dependencies(%{bad: %{version: "latest"}})
+    assert :bad in result.conflicts
+  end
+
+  test "cache key" do
+    {:ok, key1} = CargoManager.cache_key(%{name: "a"})
+    {:ok, key2} = CargoManager.cache_key(%{name: "b"})
+    assert key1 != key2
+    assert String.length(key1) == 16
+  end
+
+  test "build command release" do
+    {:ok, cmd} = CargoManager.build_command(profile: :release, features: ["nif"])
+    assert cmd =~ "cargo build --release --features nif"
+  end
+
+  test "build command debug" do
+    {:ok, cmd} = CargoManager.build_command(profile: :debug)
+    refute cmd =~ "--release"
+  end
+
+  test "bump version patch" do
+    {:ok, v} = CargoManager.bump_version("1.2.3", :patch)
+    assert v == "1.2.4"
+  end
+
+  test "bump version minor" do
+    {:ok, v} = CargoManager.bump_version("1.2.3", :minor)
+    assert v == "1.3.0"
+  end
+
+  test "bump version major" do
+    {:ok, v} = CargoManager.bump_version("1.2.3", :major)
+    assert v == "2.0.0"
+  end
+
+  test "bump invalid version" do
+    assert {:error, :invalid_version} = CargoManager.bump_version("1.2")
+  end
+end