From 0e21735a814f9f2e1c9d63113014f9e802e2ea7d Mon Sep 17 00:00:00 2001
From: "m.kindritskiy" <kindritskiy.m@gmail.com>
Date: Sat, 14 Mar 2026 18:18:06 +0200
Subject: [PATCH] Add LETS_OS and LETS_ARCH env

---
 docs/docs/changelog.md        |  1 +
 docs/docs/env.md              |  2 ++
 internal/executor/executor.go |  3 +++
 tests/default_env.bats        | 10 +++++++++-
 tests/default_env/lets.yaml   |  7 ++++++-
 5 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/docs/docs/changelog.md b/docs/docs/changelog.md
index d7509db5..30c2f7c5 100644
--- a/docs/docs/changelog.md
+++ b/docs/docs/changelog.md
@@ -7,6 +7,7 @@ title: Changelog
 
 * `[Added]` Show similar command suggestions on typos.
 * `[Changed]` Exit code 2 on unknown command.
+* `[Added]` Expose `LETS_OS` and `LETS_ARCH` environment variables at command runtime.
 * `[Removed]` Drop deprecated `eval_env` directive. Use `env` with `sh` execution mode instead.
 
 ## [0.0.59](https://github.com/lets-cli/lets/releases/tag/v0.0.59)
diff --git a/docs/docs/env.md b/docs/docs/env.md
index af9c06e1..94ac973b 100644
--- a/docs/docs/env.md
+++ b/docs/docs/env.md
@@ -19,6 +19,8 @@ title: Environment
 * `LETS_COMMAND_WORK_DIR` - absolute path to `work_dir` specified in command.
 * `LETS_CONFIG` - absolute path to lets config file.
 * `LETS_CONFIG_DIR` - absolute path to lets config file firectory.
+* `LETS_OS` - current operating system name from Go runtime, for example `linux`, `darwin`, `windows`
+* `LETS_ARCH` - current architecture name from Go runtime, for example `amd64`, `arm64`, `386`
 * `LETS_SHELL` - shell from config or command.
 * `LETSOPT_<>` - options parsed from command `options` (docopt string). E.g `lets run --env=prod --reload` will be `LETSOPT_ENV=prod` and `LETSOPT_RELOAD=true`
 * `LETSCLI_<>` - options which values is a options usage. E.g `lets run --env=prod --reload` will be `LETSCLI_ENV=--env=prod` and `LETSCLI_RELOAD=--reload`
diff --git a/internal/executor/executor.go b/internal/executor/executor.go
index 277f5fe7..9823fc33 100644
--- a/internal/executor/executor.go
+++ b/internal/executor/executor.go
@@ -8,6 +8,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"runtime"
 	"strings"
 
 	"github.com/lets-cli/lets/internal/checksum"
@@ -210,6 +211,8 @@ func (e *Executor) setupEnv(osCmd *exec.Cmd, command *config.Command, shell stri
 		"LETS_COMMAND_WORK_DIR": osCmd.Dir,
 		"LETS_CONFIG":           filepath.Base(e.cfg.FilePath),
 		"LETS_CONFIG_DIR":       filepath.Dir(e.cfg.FilePath),
+		"LETS_OS":               runtime.GOOS,
+		"LETS_ARCH":             runtime.GOARCH,
 		"LETS_SHELL":            shell,
 	}
 
diff --git a/tests/default_env.bats b/tests/default_env.bats
index b257e636..f2497f91 100644
--- a/tests/default_env.bats
+++ b/tests/default_env.bats
@@ -62,4 +62,12 @@ setup() {
 
     assert_failure
     assert_line --index 0 "failed to run command 'print-workdir': chdir ${TEST_DIR}/b: no such file or directory"
-}
\ No newline at end of file
+}
+
+@test "LETS_OS and LETS_ARCH: contain Go runtime platform values" {
+    run lets print-os-arch
+
+    assert_success
+    assert_line --index 0 "LETS_OS=$(go env GOOS)"
+    assert_line --index 1 "LETS_ARCH=$(go env GOARCH)"
+}
diff --git a/tests/default_env/lets.yaml b/tests/default_env/lets.yaml
index 849814b0..39592f04 100644
--- a/tests/default_env/lets.yaml
+++ b/tests/default_env/lets.yaml
@@ -13,4 +13,9 @@ commands:
   print-env:
     options: |
       Usage: lets print-env <env>
-    cmd: echo ${LETSOPT_ENV}=`printenv ${LETSOPT_ENV}`
\ No newline at end of file
+    cmd: echo ${LETSOPT_ENV}=`printenv ${LETSOPT_ENV}`
+
+  print-os-arch:
+    cmd: |
+      echo LETS_OS=${LETS_OS}
+      echo LETS_ARCH=${LETS_ARCH}