Plugin Config

Plugin Configuration (NemoConfig)

Defining Config

Both plugin_name AND plugin_description are required ClassVar[str] fields. Omitting either raises TypeError at class-definition time.

from typing import ClassVar
from pydantic import Field
from nemo_platform_plugin.config import NemoConfig

class MyPluginConfig(NemoConfig):
    plugin_name: ClassVar[str] = "my-plugin"           # kebab-case — matches CLI entry-point key
    plugin_description: ClassVar[str] = "Configuration for my plugin."

    debug: bool = Field(default=False)
    max_workers: int = Field(default=4)
    log_level: str = Field(default="INFO")

Environment Variable Formula

NMP_<SAFE_NAME>_<FIELD> where SAFE_NAME = plugin_name uppercased with non-word chars replaced by _.

Nested fields use _ as delimiter:

NMP_AGENTS_CONTROLLER_INTERVAL_SECONDS=10
NMP_AGENTS_CONTROLLER_PORT_RANGE_START=49152

YAML Config File

Config key in /etc/nmp/config.yaml equals plugin_name:

my_plugin:
  debug: true
  max_workers: 8

# Helm value path: platformConfig.my_plugin.debug

Override config file location: NMP_CONFIG_FILE_PATH=/my/custom/config.yaml

Priority Order

1. Environment variables (NMP_MY_PLUGIN_*) — highest
2. Config file (/etc/nmp/config.yaml)
3. Pydantic field defaults — lowest

Accessing Config

# Option 1: classmethod (preferred in plugin code)
config = MyPluginConfig.get()

# Option 2: standalone function (preferred when importing one name for all config types)
from nemo_platform_plugin.config import get_nemo_config
config = get_nemo_config(MyPluginConfig)

Both return the same cached singleton. Multiple calls in the same process return the same instance.

Example — ExampleConfig from example-plugin (verbatim)

from typing import ClassVar, Literal
from nemo_platform_plugin.config import NemoConfig
from pydantic import Field

class ExampleConfig(NemoConfig):
    plugin_name: ClassVar[str] = "example"
    plugin_description: ClassVar[str] = "Configuration for the NeMo Platform example plugin."

    greeting_style: Literal["formal", "casual"] = Field(
        default="formal",
        description=(
            "Controls the tone of /hello/{name} responses. "
            '"formal" → "Hello, {name}."  "casual" → "Hey, {name}!"'
            "  Set NMP_EXAMPLE_GREETING_STYLE to override."
        ),
    )
    log_requests: bool = Field(
        default=False,
        description=(
            "When True, each request to the items list endpoint emits a "
            "structured INFO log line including the workspace and page number. "
            "Set NMP_EXAMPLE_LOG_REQUESTS=true to enable."
        ),
    )

Usage across multiple components (no wiring needed):

# In service.py AND controller.py — both call get() independently
config = ExampleConfig.get()

Nested Config Models

Use a plain BaseModel (NOT NemoConfig) for nested sections:

from pydantic import BaseModel, Field
from nemo_platform_plugin.config import NemoConfig

class ControllerConfig(BaseModel):           # plain BaseModel — NOT NemoConfig
    interval_seconds: int = Field(default=5)
    health_check_timeout_seconds: int = Field(default=120)

class AgentsConfig(NemoConfig):
    plugin_name: ClassVar[str] = "agents"
    plugin_description: ClassVar[str] = "Configuration for the NeMo Platform agents plugin."

    controller: ControllerConfig = Field(default_factory=ControllerConfig)
    runner_backend: str = Field(default="in_memory")

Access nested fields: AgentsConfig.get().controller.interval_seconds

Set nested via env: NMP_AGENTS_CONTROLLER_INTERVAL_SECONDS=10

Test Override Pattern

from nemo_platform_plugin.config import (
    set_nemo_config_override,
    clear_nemo_config_override,
    clear_nemo_config_overrides,
)

# In a test:
def test_casual_greeting():
    set_nemo_config_override(ExampleConfig(greeting_style="casual"))
    try:
        config = ExampleConfig.get()
        assert config.greeting_style == "casual"
    finally:
        clear_nemo_config_override(ExampleConfig)

# With autouse pytest fixture (recommended):
import pytest

@pytest.fixture(autouse=True)
def reset_config():
    yield
    clear_nemo_config_overrides()   # clears ALL overrides after each test

Gotchas

• plugin_name must be kebab-case: "my-plugin" not "my_plugin". Use the same value as your CLI entry-point key. The env prefix replaces - with _ automatically.
• Both plugin_name AND plugin_description required: TypeError at class-definition time if either is missing or empty.
• Do NOT call MyPluginConfig() directly: This bypasses env/file loading. Always use MyPluginConfig.get() or get_nemo_config(MyPluginConfig).
• Do NOT set model_config manually: The _NemoConfigMeta metaclass sets it before Pydantic builds the schema. Setting it manually will be overridden and may leave the schema inconsistent.
• Config is cached per process: In tests, always clean up with clear_nemo_config_override(cls) or clear_nemo_config_overrides(). Failing to do so pollutes subsequent tests.
• Abstract intermediates: A class that declares neither plugin_name nor plugin_description is treated as an abstract intermediate (exempt from validation). Declaring plugin_description without plugin_name raises TypeError — you cannot partially fill the requirement.