diff --git a/program.go b/program.go
index 5160392..7e2f328 100644
--- a/program.go
+++ b/program.go
@@ -14,6 +14,12 @@ import (
 // Callers may use errors.Is to detect this condition.
 var ErrProgramNotFound = coreerr.E("", "program: binary not found in PATH", nil)
 
+// ErrProgramContextRequired is returned when Run or RunDir is called without a context.
+var ErrProgramContextRequired = coreerr.E("", "program: command context is required", nil)
+
+// ErrProgramNameRequired is returned when Run or RunDir is called without a program name.
+var ErrProgramNameRequired = coreerr.E("", "program: program name is empty", nil)
+
 // Program represents a named executable located on the system PATH.
 // Create one with a Name, call Find to resolve its path, then Run or RunDir.
 type Program struct {
@@ -48,11 +54,19 @@ func (p *Program) Run(ctx context.Context, args ...string) (string, error) {
 // Returns trimmed combined stdout+stderr output and any error.
 // If dir is empty, the process inherits the caller's working directory.
 func (p *Program) RunDir(ctx context.Context, dir string, args ...string) (string, error) {
+	if ctx == nil {
+		return "", coreerr.E("Program.RunDir", "program: command context is required", ErrProgramContextRequired)
+	}
+
 	binary := p.Path
 	if binary == "" {
 		binary = p.Name
 	}
 
+	if binary == "" {
+		return "", coreerr.E("Program.RunDir", "program name is empty", ErrProgramNameRequired)
+	}
+
 	var out bytes.Buffer
 	cmd := exec.CommandContext(ctx, binary, args...)
 	cmd.Stdout = &out
diff --git a/program_test.go b/program_test.go
index 970e2de..739e516 100644
--- a/program_test.go
+++ b/program_test.go
@@ -78,3 +78,19 @@ func TestProgram_Run_FailingCommand(t *testing.T) {
 	_, err := p.Run(testCtx(t))
 	require.Error(t, err)
 }
+
+func TestProgram_Run_NilContextRejected(t *testing.T) {
+	p := &process.Program{Name: "echo"}
+
+	_, err := p.Run(nil, "test")
+	require.Error(t, err)
+	assert.ErrorIs(t, err, process.ErrProgramContextRequired)
+}
+
+func TestProgram_RunDir_EmptyNameRejected(t *testing.T) {
+	p := &process.Program{}
+
+	_, err := p.RunDir(testCtx(t), "", "test")
+	require.Error(t, err)
+	assert.ErrorIs(t, err, process.ErrProgramNameRequired)
+}