diff --git a/README.md b/README.md
index f02aed6..7a206a1 100644
--- a/README.md
+++ b/README.md
@@ -1,10 +1,11 @@
 # ReleaseKit
 
 ReleaseKit is an opinionated Go library and executable for a shared release
-process. The Go module and documented root `releasekit` facade are established;
-the library operations, runtime version package, executable, tests, and release
-automation remain to be implemented. Their selected behavior and sequence are
-described in the [product roadmap](docs/roadmap/releasekit.md) and
+process. The Go module, root `releasekit` facade, `buildinfo` runtime package,
+and `releasekit version` command are established; the library operations beyond
+runtime version access, remaining CLI commands, and release automation remain
+to be implemented. Their selected behavior and sequence are described in the
+[product roadmap](docs/roadmap/releasekit.md) and
 [implementation plan](docs/roadmap/implementation.md).
 
 Run the offline Go test suite from the repository root with:
@@ -13,6 +14,12 @@ Run the offline Go test suite from the repository root with:
 go test ./...
 ```
 
+The current command prints ReleaseKit's version:
+
+```sh
+go run ./cmd/releasekit version
+```
+
 ## Documentation
 
 - [ReleaseKit proposal](docs/roadmap/releasekit.md): proposed publication, builds,
@@ -21,6 +28,8 @@ go test ./...
   policy reading.
 - [Architecture policy](docs/policy/architecture.md): responsibility and dependency
   boundaries for development.
+- [Runtime version guidance](docs/runtime.md): how applications read their
+  embedded version through `buildinfo`.
 - [ADR 0001](docs/adr/0001-public-facade.md): the accepted public facade decision.
 - [Policy adoption roadmap](docs/roadmap/policy.md): completed adoption and pending
   release bootstrap work.
diff --git a/buildinfo/version.go b/buildinfo/version.go
new file mode 100644
index 0000000..8da33c3
--- /dev/null
+++ b/buildinfo/version.go
@@ -0,0 +1,12 @@
+// Package buildinfo provides runtime version information for applications
+// built with ReleaseKit.
+package buildinfo
+
+import "gitea.maximumdirect.net/eric/ReleaseKit/internal/runtimeinfo"
+
+// Version returns the injected release identifier when available. Otherwise,
+// it returns the executable's main module version, or "dev" when that metadata
+// is unavailable or identifies a development build.
+func Version() string {
+	return runtimeinfo.Version()
+}
diff --git a/buildinfo/version_integration_test.go b/buildinfo/version_integration_test.go
new file mode 100644
index 0000000..ff8f1af
--- /dev/null
+++ b/buildinfo/version_integration_test.go
@@ -0,0 +1,81 @@
+package buildinfo_test
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/ReleaseKit/internal/versioncontract"
+)
+
+func TestVersionInConsumerExecutable(t *testing.T) {
+	repo, err := filepath.Abs("..")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	dir := t.TempDir()
+	module := fmt.Sprintf(`module example.com/versionfixture
+
+go 1.25.0
+
+require gitea.maximumdirect.net/eric/ReleaseKit v0.0.0
+
+replace gitea.maximumdirect.net/eric/ReleaseKit => %s
+`, filepath.ToSlash(repo))
+	if err := os.WriteFile(filepath.Join(dir, "go.mod"), []byte(module), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	program := `package main
+
+import (
+	"fmt"
+	"gitea.maximumdirect.net/eric/ReleaseKit/buildinfo"
+)
+
+func main() { fmt.Print(buildinfo.Version()) }
+`
+	if err := os.WriteFile(filepath.Join(dir, "main.go"), []byte(program), 0o600); err != nil {
+		t.Fatal(err)
+	}
+
+	for _, test := range []struct {
+		name       string
+		linkerArgs []string
+		want       string
+	}{
+		{name: "development build", want: "dev"},
+		{
+			name:       "injected release version",
+			linkerArgs: []string{"-X", versioncontract.InjectedVersionLinkerSymbol + "=v1.2.3"},
+			want:       "v1.2.3",
+		},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			binary := filepath.Join(t.TempDir(), "versionfixture")
+			args := []string{"build", "-o", binary}
+			if len(test.linkerArgs) > 0 {
+				args = append(args, "-ldflags", fmt.Sprint(test.linkerArgs[0], " ", test.linkerArgs[1]))
+			}
+			args = append(args, ".")
+
+			build := exec.Command("go", args...)
+			build.Dir = dir
+			build.Env = append(os.Environ(), "GOTOOLCHAIN=local", "GOPROXY=off", "GOSUMDB=off")
+			if output, err := build.CombinedOutput(); err != nil {
+				t.Fatalf("build consumer fixture: %v\n%s", err, output)
+			}
+
+			command := exec.Command(binary)
+			output, err := command.CombinedOutput()
+			if err != nil {
+				t.Fatalf("run consumer fixture: %v\n%s", err, output)
+			}
+			if string(output) != test.want {
+				t.Fatalf("version output = %q, want %q", output, test.want)
+			}
+		})
+	}
+}
diff --git a/cmd/releasekit/main.go b/cmd/releasekit/main.go
new file mode 100644
index 0000000..361bb1a
--- /dev/null
+++ b/cmd/releasekit/main.go
@@ -0,0 +1,23 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"os"
+
+	"gitea.maximumdirect.net/eric/ReleaseKit/buildinfo"
+)
+
+func main() {
+	os.Exit(run(os.Args[1:], os.Stdout, os.Stderr))
+}
+
+func run(args []string, stdout, stderr io.Writer) int {
+	if len(args) == 1 && args[0] == "version" {
+		fmt.Fprintf(stdout, "releasekit %s\n", buildinfo.Version())
+		return 0
+	}
+
+	fmt.Fprintln(stderr, "usage: releasekit version")
+	return 2
+}
diff --git a/cmd/releasekit/main_test.go b/cmd/releasekit/main_test.go
new file mode 100644
index 0000000..82f4abb
--- /dev/null
+++ b/cmd/releasekit/main_test.go
@@ -0,0 +1,35 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/ReleaseKit/buildinfo"
+)
+
+func TestVersionCommand(t *testing.T) {
+	var stdout, stderr bytes.Buffer
+	if status := run([]string{"version"}, &stdout, &stderr); status != 0 {
+		t.Fatalf("run() status = %d, want 0; stderr = %q", status, stderr.String())
+	}
+	if want := fmt.Sprintf("releasekit %s\n", buildinfo.Version()); stdout.String() != want {
+		t.Fatalf("version output = %q, want %q", stdout.String(), want)
+	}
+	if stderr.Len() != 0 {
+		t.Fatalf("version command wrote to stderr: %q", stderr.String())
+	}
+}
+
+func TestUnknownCommand(t *testing.T) {
+	var stdout, stderr bytes.Buffer
+	if status := run([]string{"publish"}, &stdout, &stderr); status != 2 {
+		t.Fatalf("run() status = %d, want 2", status)
+	}
+	if stdout.Len() != 0 {
+		t.Fatalf("unknown command wrote to stdout: %q", stdout.String())
+	}
+	if want := "usage: releasekit version\n"; stderr.String() != want {
+		t.Fatalf("usage output = %q, want %q", stderr.String(), want)
+	}
+}
diff --git a/docs/development.md b/docs/development.md
index 8e88403..5879b69 100644
--- a/docs/development.md
+++ b/docs/development.md
@@ -42,10 +42,10 @@ Run the offline Go test suite from the repository root with:
 go test ./...
 ```
 
-The implemented package inventory currently contains only the root
-`releasekit` facade package. Its public operations are added as their behavior is
-implemented; see the [implementation plan](roadmap/implementation.md) for
-current progress.
+The implemented package inventory currently contains the root `releasekit`
+facade and `buildinfo` runtime facade, plus the `cmd/releasekit` executable.
+Orchestration operations are added as their behavior is implemented; see the
+[implementation plan](roadmap/implementation.md) for current progress.
 
 For prose changes, review the diff and check local links, fragment destinations,
 provenance, template residue, and consistency with current repository contents.
diff --git a/docs/roadmap/implementation.md b/docs/roadmap/implementation.md
index 9fd1560..e56596a 100644
--- a/docs/roadmap/implementation.md
+++ b/docs/roadmap/implementation.md
@@ -456,7 +456,7 @@ LGPL licensing and attribution notices remain consistent.
 
 ## Stage 2: Implement the runtime version facade
 
-Status: Pending. Depends on Stage 1.
+Status: Complete. Depends on Stage 1.
 
 1. Implement `buildinfo.Version` and its internal injected-string and main-module
    fallback logic. Keep runtime state private and the public accessor small.
@@ -470,6 +470,15 @@ Acceptance: a source-built fixture reports `dev`; a fixture linked with a stable
 version reports that version. Fallback metadata uses the executable main module.
 CLI version output is correct and no runtime orchestration initialization occurs.
 
+Completion evidence: implemented `buildinfo.Version`, its private injected
+string and main-module fallback, and the internal linker-symbol contract. Unit
+tests cover injection precedence and missing, development, and stable main
+module metadata. Built and ran a separate consumer executable from source and
+with an injected stable version using network-disabled Go commands; both
+reported the selected value. CLI tests cover its version line, and the CLI's
+dependency closure contains no orchestration package. Added runtime consumer
+guidance and documented the command contract.
+
 ## Stage 3: Protect public contracts and dependency direction
 
 Status: Pending. Depends on Stage 2.
diff --git a/docs/runtime.md b/docs/runtime.md
new file mode 100644
index 0000000..f608fc8
--- /dev/null
+++ b/docs/runtime.md
@@ -0,0 +1,24 @@
+# Runtime version
+
+Applications can read their embedded version through the public `buildinfo`
+package:
+
+```go
+import "gitea.maximumdirect.net/eric/ReleaseKit/buildinfo"
+
+version := buildinfo.Version()
+```
+
+`Version` returns the identifier injected into the executable when present.
+Otherwise it returns the executable's main module version when that metadata is
+available and is not `(devel)`. It returns `dev` when neither source provides a
+release identifier. Applications should use this accessor for version output;
+the runtime implementation and ReleaseKit's builder own the injection detail.
+
+ReleaseKit's current command prints its own runtime version:
+
+```sh
+go run ./cmd/releasekit version
+```
+
+The output has the form `releasekit <version>`.
diff --git a/internal/runtimeinfo/version.go b/internal/runtimeinfo/version.go
new file mode 100644
index 0000000..a4e4702
--- /dev/null
+++ b/internal/runtimeinfo/version.go
@@ -0,0 +1,26 @@
+// Package runtimeinfo implements the private runtime version state used by the
+// public buildinfo facade.
+package runtimeinfo
+
+import "runtime/debug"
+
+var injectedVersion string
+
+// Version returns the injected version or the running executable's main module
+// version, falling back to "dev" when neither provides a release identifier.
+func Version() string {
+	return version(injectedVersion, debug.ReadBuildInfo)
+}
+
+func version(injected string, readBuildInfo func() (*debug.BuildInfo, bool)) string {
+	if injected != "" {
+		return injected
+	}
+
+	info, ok := readBuildInfo()
+	if ok && info != nil && info.Main.Version != "" && info.Main.Version != "(devel)" {
+		return info.Main.Version
+	}
+
+	return "dev"
+}
diff --git a/internal/runtimeinfo/version_test.go b/internal/runtimeinfo/version_test.go
new file mode 100644
index 0000000..9d53891
--- /dev/null
+++ b/internal/runtimeinfo/version_test.go
@@ -0,0 +1,57 @@
+package runtimeinfo
+
+import (
+	"runtime/debug"
+	"testing"
+)
+
+func TestVersion(t *testing.T) {
+	tests := []struct {
+		name     string
+		injected string
+		info     *debug.BuildInfo
+		ok       bool
+		want     string
+	}{
+		{
+			name:     "injected version takes precedence",
+			injected: "v1.2.3",
+			info:     &debug.BuildInfo{Main: debug.Module{Version: "v4.5.6"}},
+			ok:       true,
+			want:     "v1.2.3",
+		},
+		{
+			name: "main module version",
+			info: &debug.BuildInfo{Main: debug.Module{Version: "v4.5.6"}},
+			ok:   true,
+			want: "v4.5.6",
+		},
+		{
+			name: "missing build information",
+			want: "dev",
+		},
+		{
+			name: "development main module",
+			info: &debug.BuildInfo{Main: debug.Module{Version: "(devel)"}},
+			ok:   true,
+			want: "dev",
+		},
+		{
+			name: "empty main module version",
+			info: &debug.BuildInfo{Main: debug.Module{}},
+			ok:   true,
+			want: "dev",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			got := version(test.injected, func() (*debug.BuildInfo, bool) {
+				return test.info, test.ok
+			})
+			if got != test.want {
+				t.Fatalf("version() = %q, want %q", got, test.want)
+			}
+		})
+	}
+}
diff --git a/internal/versioncontract/injection.go b/internal/versioncontract/injection.go
new file mode 100644
index 0000000..9a52e6b
--- /dev/null
+++ b/internal/versioncontract/injection.go
@@ -0,0 +1,7 @@
+// Package versioncontract holds the internal contract shared by runtime
+// version reporting and the release builder.
+package versioncontract
+
+// InjectedVersionLinkerSymbol is the -X linker target used to set the runtime
+// version. Keep it in sync with runtimeinfo.injectedVersion.
+const InjectedVersionLinkerSymbol = "gitea.maximumdirect.net/eric/ReleaseKit/internal/runtimeinfo.injectedVersion"