2.4 Extension Types

Header file:

• src/service/extension/include/extension_types.h

Implementation reference:

• src/service/extension/service/extension_service.cpp
• src/api/c99/src/c_arm_extension.cpp

Overview

The ExtensionClient module uses a three-layer structure to represent plugin data: base info, running state, and complete details.

GetList() returns std::vector<ExtensionInfo> , Get(const std::string& name) returns a single ExtensionInfo , C99 Arm_Extension_GetList / Arm_Extension_Get serialize the same structure into compact JSON text.

2.4.1 JSON Shape

Single plugin details:

{
  "extension": {
    "name": "demo",
    "author": "agilebot",
    "type": "easyservice",
    "scriptLang": "python",
    "description": "demo extension",
    "version": "1.0.0",
    "contact": "",
    "copyright": "",
    "license": "",
    "entry": "main.py",
    "url": "http://127.0.0.1:9000"
  },
  "state": {
    "enabled": true,
    "isRunning": true,
    "port": 9000
  }
}

Plugin list:

[
  {
    "extension": {},
    "state": {}
  }
]

Field names maintain server-side camelCase convention: scriptLang , isRunning are not converted to snake_case.

2.4.2 ExtensionBaseInfo

Field	Type	Description
name	std::string	Plugin name
author	std::string	Author
type	std::string	Plugin type
scriptLang	std::string	Script language, uses camelCase to align with Python
description	std::string	Description
version	std::string	Version
contact	std::string	Contact
copyright	std::string	Copyright
license	std::string	License
entry	std::string	Entry file
url	std::string	Web plugin access URL

These fields all come from the extensionClient node in the returned JSON.

2.4.3 ExtensionState

Field	Type	Description
enabled	bool	Whether enabled
isRunning	bool	Whether running, uses camelCase to align with Python
port	int32_t	Service port; defaults to 0 when missing

These fields all come from the state node in the returned JSON.

2.4.4 ExtensionInfo

Field	Type	Description
extensionClient	ExtensionBaseInfo	Base info
state	ExtensionState	Running state

ExtensionInfo is the unified return structure of the ExtensionClient module:

• GetList() returns std::vector<ExtensionInfo>
• Get() returns a single ExtensionInfo
• C99 Arm_Extension_GetList / Arm_Extension_Get return JSON with the same field names

2.4.5 Default Value Conventions

• When the server returns with missing fields, string fields are filled with empty strings.
• When enabled / isRunning are missing, they default to false .
• When port is missing or has invalid type, it defaults to 0 .

If top-level extensionClient / state nodes are missing, the SDK treats them as empty objects, then fills in default values field by field.

2.4.6 C99 Mapping Interface

C99 Interface	Output Content
Arm_Extension_GetList	Compact JSON text of ExtensionInfo[]
Arm_Extension_Get	Compact JSON text of single ExtensionInfo

Additional conventions:

• C99 output uses UTF-8 compact JSON without extra indentation.
• Field names are consistent with C++ structs, no case conversion.
• Arm_Extension_CallService returns the JSON text of the service result result , not part of the ExtensionInfo structure family.

2.4.7 Related Method Pages

• 3.12 ExtensionClient
• 4.12 C99 Extension