metabuilder/workflow/plugins/STRUCTURE.md

Plugin Structure - Multi-Language Support

Directory Organization

Plugins are organized by language first, then by category:

workflow/
├── executor/                # Language-specific runtimes
│   ├── ts/                  # TypeScript runtime + core engine
│   │   ├── executor/        # DAG executor
│   │   ├── registry/        # Plugin registry
│   │   ├── utils/           # Priority queue, template engine
│   │   ├── types.ts         # Type definitions
│   │   └── index.ts         # Main exports
│   ├── python/              # Python executor (child process)
│   └── cpp/                 # C++ executor (native FFI)
│
├── plugins/                 # All plugins by language
│   ├── ts/                  # TypeScript plugins
│   │   ├── dbal/
│   │   │   ├── dbal-read/
│   │   │   └── dbal-write/
│   │   ├── integration/
│   │   │   ├── http-request/
│   │   │   ├── email-send/
│   │   │   └── webhook-response/
│   │   ├── control-flow/
│   │   │   └── condition/
│   │   └── utility/
│   │       ├── transform/
│   │       ├── wait/
│   │       └── set-variable/
│   │
│   └── python/              # Python plugins (from AutoMetabuilder)
│       ├── control/         # Bot control, switch logic
│       ├── convert/         # Type conversions
│       ├── core/            # AI requests, message handling
│       ├── dict/            # Dictionary operations
│       ├── list/            # List operations
│       ├── logic/           # Boolean logic
│       ├── math/            # Mathematical operations
│       ├── notifications/   # Slack, Discord
│       ├── string/          # String manipulation
│       ├── test/            # Unit testing assertions
│       ├── tools/           # External tool integration
│       ├── utils/           # Utility functions
│       ├── var/             # Variable management
│       └── web/             # Flask server, API endpoints
│
├── package.json
└── tsconfig.json

Plugin Categories

TypeScript Plugins (plugins/ts/)

Category	Plugins	Purpose
dbal	dbal-read, dbal-write	Database operations
integration	http-request, email-send, webhook-response	External services
control-flow	condition	Workflow control
utility	transform, wait, set-variable	Data manipulation

Python Plugins (plugins/python/)

Category	Plugins	Purpose
control	control_switch, control_start_bot, control_get_bot_status	Bot control
convert	convert_to_*, convert_parse_json	Type conversion
core	core_ai_request, core_load_context, core_run_tool_calls	AI operations
dict	dict_get, dict_set, dict_keys, dict_values, dict_merge	Dictionary ops
list	list_concat, list_find, list_sort, list_slice	List operations
logic	logic_and, logic_or, logic_equals, logic_gt, logic_lt	Comparisons
math	math_add, math_subtract, math_multiply, math_divide	Arithmetic
notifications	notifications_slack, notifications_discord	Notifications
string	string_concat, string_split, string_replace, string_format	String ops
test	test_assert_equals, test_assert_true, test_run_suite	Testing
tools	tools_read_file, tools_run_tests, tools_run_docker	External tools
utils	utils_filter_list, utils_map_list, utils_check_mvp	Utilities
var	var_get, var_set, var_delete, var_exists	Variables
web	web_create_flask_app, web_start_server, web_get_env_vars	Web/Flask

Plugin Interface

TypeScript Plugin

// plugins/ts/dbal/dbal-read/src/index.ts
export class DBALReadExecutor implements INodeExecutor {
  nodeType = 'dbal-read';

  async execute(
    node: WorkflowNode,
    context: WorkflowContext,
    state: ExecutionState
  ): Promise<NodeResult> {
    // Implementation
  }
}

Python Plugin

# plugins/python/math/math_add.py
def run(_runtime, inputs):
    """Add two or more numbers."""
    numbers = inputs.get("numbers", [])
    return {"result": sum(numbers)}

Execution Flow

┌─────────────────────────────────────────┐
│  DAGExecutor (executor/ts/executor/)    │
│  - Resolves node dependencies           │
│  - Schedules execution                  │
└─────────────────┬───────────────────────┘
                  │
                  ↓
┌─────────────────────────────────────────┐
│  NodeExecutorRegistry (executor/ts/)    │
│  - Looks up plugin by nodeType          │
│  - Determines language from metadata    │
└─────────────────┬───────────────────────┘
                  │
        ┌─────────┼─────────┐
        │         │         │
        ↓         ↓         ↓
    ┌────────┬────────┬────────┐
    │   TS   │ Python │  C++   │
    │Executor│Executor│Executor│
    └────────┴────────┴────────┘
        │         │         │
        ↓         ↓         ↓
    ┌────────┬────────┬────────┐
    │plugins/│plugins/│plugins/│
    │  ts/   │python/ │  cpp/  │
    └────────┴────────┴────────┘

Performance Characteristics

Language	Execution Speed	Memory	Startup	Best For
TypeScript	1x baseline	High	Fast	Orchestration, logic
Python	0.1-1x	Medium	Medium	AI/ML, data science
C++	100-1000x	Low	Slow	Bulk ops, aggregations

Best Practices

Choose Language Based On:

TypeScript

• REST APIs and webhooks
• JSON transformations
• Simple orchestration
• Rapid development

Python

• Machine learning tasks
• Natural language processing
• Data science operations
• AI model integration

C++

• Large dataset processing (1M+ rows)
• Complex aggregations
• Performance-critical operations
• Memory-intensive operations