Plugin System

agent-skills uses Python entry points for extensibility. Third-party packages can register custom authentication backends, protocol invokers, or binding sources.

Plugin groups

Group	Purpose	Example
agent_skills.auth	Authentication backends	OAuth, LDAP, custom SSO
agent_skills.invoker	Protocol invokers	gRPC, GraphQL, custom protocols
agent_skills.binding_source	Binding/service sources	Community registries, private catalogs

Registering a plugin

In your package's pyproject.toml:

[project.entry-points."agent_skills.invoker"]
grpc = "my_package.grpc_invoker:GRPCInvoker"

Or in setup.cfg:

[options.entry_points]
agent_skills.invoker =
    grpc = my_package.grpc_invoker:GRPCInvoker

Discovery API

from runtime.plugins import discover_plugins, discover_all

# Discover plugins for a specific group
invokers = discover_plugins("agent_skills.invoker")
# → {"grpc": <class GRPCInvoker>}

# Discover all registered plugins
all_plugins = discover_all()
# → {"agent_skills.auth": {...}, "agent_skills.invoker": {...}, ...}

Plugins are discovered at startup by engine_factory.build_runtime_components(). Failed plugin loads are logged as warnings but do not prevent startup.

Creating an invoker plugin

An invoker must implement the protocol invoker interface:

class GRPCInvoker:
    def invoke(self, request):
        """Execute the invocation and return an InvocationResponse."""
        ...

Register it and install your package — it will be discovered automatically on the next engine startup.

Creating an auth plugin

An auth backend must be callable as a token verifier:

def my_verifier(token: str) -> Identity | None:
    """Verify token and return Identity or None."""
    ...

Pass it to AuthMiddleware(token_verifier=my_verifier).