Extension types

OpenBB discovers extensions through Python entry points declared in each package's pyproject.toml. A single distribution can register entry points in any combination of groups. Every V5 data package does this: it registers a provider under openbb_provider_extension and its own command namespace under openbb_core_extension, so installing openbb-famafrench adds both the famafrench provider and obb.famafrench.

Router extensions: openbb_core_extension

A router extension adds a top-level namespace to obb and the same commands as HTTP routes under /api/v1/<name>. Each command is a function decorated with @router.command(...).

The entry point must resolve to an already-constructed openbb_core.app.router.Router, fastapi.FastAPI, or fastapi.APIRouter instance. A FastAPI app contributes its .router, and an APIRouter is wrapped in a Router. Factory functions are not called; an entry point that resolves to anything else is skipped.

[project.entry-points."openbb_core_extension"]
my_router = "my_package.my_router:router"

The entry-point name becomes the namespace: obb.my_router.* and /api/v1/my_router/*.

With the openbb-core[flask] extra installed, an entry point in this group can also resolve to a Flask application. Flask apps are mounted on the REST API at /api/v1/<name> and their routes are merged into the OpenAPI schema; they do not appear in the Python Interface.

Provider extensions: openbb_provider_extension

A provider extension supplies data for one or more models. It declares a Provider whose fetcher_dict maps model names to Fetcher subclasses. A router command declared with model="<ModelName>" offers every installed provider that has that key, and at call time the engine runs the selected provider's fetcher. Streaming providers implement stream_data instead of transform_data; see Streaming responses.

The entry point must resolve to an openbb_core.provider.abstract.provider.Provider instance.

[project.entry-points."openbb_provider_extension"]
my_provider = "my_package:my_provider"

Callers select the provider with provider="<name>", where <name> is the name argument given to Provider(...). Keep the entry-point name the same to avoid confusion; openbb-us-eia is an exception, registering the entry point us_eia for a provider named eia.

OBBject extensions: openbb_obbject_extension

An OBBject extension attaches an accessor to every OBBject, or runs a callback on command output. The entry point must resolve to an openbb_core.app.model.extension.Extension instance; other objects are ignored.

[project.entry-points."openbb_obbject_extension"]
my_accessor = "my_package:ext"

By default an extension registers a pandas-style accessor, so callers write obbject.<extension name>.<method>(...). The accessor object is created on first access and cached on that OBBject. OBBject extensions shows both the class and function forms.

Setting on_command_output=True turns the extension into a callback that runs after matching commands, on both the Python Interface and the REST API. It only loads when allow_on_command_output is enabled in the system settings or OPENBB_ALLOW_ON_COMMAND_OUTPUT is set. command_output_paths limits it to specific routes, results_only=True makes the command return only results, and immutable=False lets it modify the returned OBBject, which additionally requires allow_mutable_extensions or OPENBB_ALLOW_MUTABLE_EXTENSIONS. OBBject plugins covers the details.

Charting extensions: openbb_charting_extension

A charting extension provides chart views for routes registered by router extensions. openbb-charting loads every entry point in this group and matches views to commands by method name; the entry-point name is not used for matching.

The entry point must resolve to a class. Each public static method defined in that class's module is a view, named after the route it charts: the leading / is dropped and the remaining / become _. The IMF provider's view for /imf/portwatch/country_activity is ImfViews.imf_portwatch_country_activity:

class ImfViews:
    """IMF chart views."""

    @staticmethod
    def imf_portwatch_country_activity(**kwargs):
        """Chart port activity for a country."""
        ...

[project.entry-points."openbb_charting_extension"]
imf = "openbb_imf.imf_views:ImfViews"

A view receives keyword arguments that include the command's results as obbject_item, and returns a Chart model, a figure, or a (figure, content) tuple. Installing a view adds a chart parameter to the command after the next build. Charting extensions has the full contract.

openbb-core also resolves two charting groups of its own: openbb_charting_hooks for ChartingHook subclasses that run at stages of chart creation, and openbb_charting_backend for a rendering backend selected by the charting_backend system setting.

Summary

Group	Adds	Entry-point target
openbb_core_extension	Commands and namespaces	Router, FastAPI, or APIRouter instance (or a Flask app, REST only)
openbb_provider_extension	Data sources for models	Provider instance
openbb_obbject_extension	Accessors on OBBject, or command-output callbacks	Extension instance
openbb_charting_extension	Chart views for routes	A class whose static methods are named after routes