Add engine.command field to use custom CLI executable

pkg/parser/schemas/main_workflow_schema.json

@@ -5944,6 +5944,10 @@
               "type": "string",
               "description": "Custom user agent string for GitHub MCP server configuration (codex engine only)"
             },
+            "command": {
+              "type": "string",
+              "description": "Custom executable path for the AI engine CLI. When specified, the workflow will skip the standard installation steps and use this command instead. The command should be the full path to the executable or a command available in PATH."
+            },
             "env": {
               "type": "object",
               "description": "Custom environment variables to pass to the AI engine, including secret overrides (e.g., OPENAI_API_KEY: ${{ secrets.CUSTOM_KEY }})",

pkg/workflow/claude_engine.go

@@ -57,6 +57,12 @@ func (e *ClaudeEngine) GetRequiredSecretNames(workflowData *WorkflowData) []stri
 func (e *ClaudeEngine) GetInstallationSteps(workflowData *WorkflowData) []GitHubActionStep {
 	claudeLog.Printf("Generating installation steps for Claude engine: workflow=%s", workflowData.Name)
 
+	// Skip installation if custom command is specified
+	if workflowData.EngineConfig != nil && workflowData.EngineConfig.Command != "" {
+		claudeLog.Printf("Skipping installation steps: custom command specified (%s)", workflowData.EngineConfig.Command)
+		return []GitHubActionStep{}
+	}
+
 	var steps []GitHubActionStep
 
 	// Define engine configuration for shared validation
@@ -214,8 +220,17 @@ func (e *ClaudeEngine) GetExecutionSteps(workflowData *WorkflowData, logFile str
 	}
 
 	// Build the command string with proper argument formatting
-	// Use claude command directly (available in PATH from hostedtoolcache mount)
-	commandParts := []string{"claude"}
+	// Determine which command to use
+	var commandName string
+	if workflowData.EngineConfig != nil && workflowData.EngineConfig.Command != "" {
+		commandName = workflowData.EngineConfig.Command
+		claudeLog.Printf("Using custom command: %s", commandName)
+	} else {
+		// Use claude command directly (available in PATH from hostedtoolcache mount)
+		commandName = "claude"
+	}
+
+	commandParts := []string{commandName}
 	commandParts = append(commandParts, claudeArgs...)
 	commandParts = append(commandParts, promptCommand)
 

pkg/workflow/claude_engine_test.go

@@ -511,3 +511,17 @@ func TestClaudeEngineNoDoubleEscapePrompt(t *testing.T) {
 		}
 	})
 }
+
+func TestClaudeEngineSkipInstallationWithCommand(t *testing.T) {
+	engine := NewClaudeEngine()
+
+	// Test with custom command - should skip installation
+	workflowData := &WorkflowData{
+		EngineConfig: &EngineConfig{Command: "/usr/local/bin/custom-claude"},
+	}
+	steps := engine.GetInstallationSteps(workflowData)
+
+	if len(steps) != 0 {
+		t.Errorf("Expected 0 installation steps when command is specified, got %d", len(steps))
+	}
+}

pkg/workflow/codex_engine.go

@@ -69,6 +69,12 @@ func (e *CodexEngine) GetRequiredSecretNames(workflowData *WorkflowData) []strin
 func (e *CodexEngine) GetInstallationSteps(workflowData *WorkflowData) []GitHubActionStep {
 	codexEngineLog.Printf("Generating installation steps for Codex engine: workflow=%s", workflowData.Name)
 
+	// Skip installation if custom command is specified
+	if workflowData.EngineConfig != nil && workflowData.EngineConfig.Command != "" {
+		codexEngineLog.Printf("Skipping installation steps: custom command specified (%s)", workflowData.EngineConfig.Command)
+		return []GitHubActionStep{}
+	}
+
 	// Use base installation steps (secret validation + npm install)
 	steps := GetBaseInstallationSteps(EngineInstallConfig{
 		Secrets:    []string{"CODEX_API_KEY", "OPENAI_API_KEY"},
@@ -158,10 +164,19 @@ func (e *CodexEngine) GetExecutionSteps(workflowData *WorkflowData, logFile stri
 	}
 
 	// Build the Codex command
-	// Use regular codex command regardless of firewall status
-	// PATH will be set to find codex in hostedtoolcache when firewall is enabled
-	codexCommand := fmt.Sprintf("codex %sexec%s%s%s\"$INSTRUCTION\"",
-		modelParam, webSearchParam, fullAutoParam, customArgsParam)
+	// Determine which command to use
+	var commandName string
+	if workflowData.EngineConfig != nil && workflowData.EngineConfig.Command != "" {
+		commandName = workflowData.EngineConfig.Command
+		codexEngineLog.Printf("Using custom command: %s", commandName)
+	} else {
+		// Use regular codex command regardless of firewall status
+		// PATH will be set to find codex in hostedtoolcache when firewall is enabled
+		commandName = "codex"
+	}
+
+	codexCommand := fmt.Sprintf("%s %sexec%s%s%s\"$INSTRUCTION\"",
+		commandName, modelParam, webSearchParam, fullAutoParam, customArgsParam)
 
 	// Build the full command with agent file handling and AWF wrapping if enabled
 	var command string
@@ -289,18 +304,27 @@ mkdir -p "$CODEX_HOME/logs"
 		}
 	} else {
 		// Build the command without AWF wrapping
+		// Determine which command to use
+		var commandName string
+		if workflowData.EngineConfig != nil && workflowData.EngineConfig.Command != "" {
+			commandName = workflowData.EngineConfig.Command
+			codexEngineLog.Printf("Using custom command: %s", commandName)
+		} else {
+			commandName = "codex"
+		}
+
 		if workflowData.AgentFile != "" {
 			agentPath := ResolveAgentFilePath(workflowData.AgentFile)
 			command = fmt.Sprintf(`set -o pipefail
 AGENT_CONTENT="$(awk 'BEGIN{skip=1} /^---$/{if(skip){skip=0;next}else{skip=1;next}} !skip' %s)"
 INSTRUCTION="$(printf "%%s\n\n%%s" "$AGENT_CONTENT" "$(cat "$GH_AW_PROMPT")")"
 mkdir -p "$CODEX_HOME/logs"
-codex %sexec%s%s%s"$INSTRUCTION" 2>&1 | tee %s`, agentPath, modelParam, webSearchParam, fullAutoParam, customArgsParam, logFile)
+%s %sexec%s%s%s"$INSTRUCTION" 2>&1 | tee %s`, agentPath, commandName, modelParam, webSearchParam, fullAutoParam, customArgsParam, logFile)
 		} else {
 			command = fmt.Sprintf(`set -o pipefail
 INSTRUCTION="$(cat "$GH_AW_PROMPT")"
 mkdir -p "$CODEX_HOME/logs"
-codex %sexec%s%s%s"$INSTRUCTION" 2>&1 | tee %s`, modelParam, webSearchParam, fullAutoParam, customArgsParam, logFile)
+%s %sexec%s%s%s"$INSTRUCTION" 2>&1 | tee %s`, commandName, modelParam, webSearchParam, fullAutoParam, customArgsParam, logFile)
 		}
 	}
 

pkg/workflow/codex_engine_test.go

@@ -732,3 +732,17 @@ func TestCodexEngineHttpMCPServerRendered(t *testing.T) {
 		})
 	}
 }
+
+func TestCodexEngineSkipInstallationWithCommand(t *testing.T) {
+	engine := NewCodexEngine()
+
+	// Test with custom command - should skip installation
+	workflowData := &WorkflowData{
+		EngineConfig: &EngineConfig{Command: "/usr/local/bin/custom-codex"},
+	}
+	steps := engine.GetInstallationSteps(workflowData)
+
+	if len(steps) != 0 {
+		t.Errorf("Expected 0 installation steps when command is specified, got %d", len(steps))
+	}
+}