resource

fastmcp.resources.resource

Base classes and interfaces for FastMCP resources.

Classes

Resource

Base class for all resources.

Methods:

enable

enable(self) -> None

disable

disable(self) -> None

from_function

from_function(fn: Callable[..., Any], uri: str | AnyUrl, name: str | None = None, title: str | None = None, description: str | None = None, mime_type: str | None = None, tags: set[str] | None = None, enabled: bool | None = None, annotations: Annotations | None = None, meta: dict[str, Any] | None = None) -> FunctionResource

set_default_mime_type

set_default_mime_type(cls, mime_type: str | None) -> str

Set default MIME type if not provided.

set_default_name

set_default_name(self) -> Self

Set default name from URI if not provided.

read

read(self) -> str | bytes

Read the resource content.

to_mcp_resource

to_mcp_resource(self, **overrides: Any) -> MCPResource

Convert the resource to an MCPResource.

key

key(self) -> str

The key of the component. This is used for internal bookkeeping and may reflect e.g. prefixes or other identifiers. You should not depend on keys having a certain value, as the same tool loaded from different hierarchies of servers may have different keys.

FunctionResource

A resource that defers data loading by wrapping a function.

The function is only called when the resource is read, allowing for lazy loading of potentially expensive data. This is particularly useful when listing resources, as the function won’t be called until the resource is actually accessed.

The function can return:

• str for text content (default)
• bytes for binary content
• other types will be converted to JSON

Methods:

from_function

from_function(cls, fn: Callable[..., Any], uri: str | AnyUrl, name: str | None = None, title: str | None = None, description: str | None = None, mime_type: str | None = None, tags: set[str] | None = None, enabled: bool | None = None, annotations: Annotations | None = None, meta: dict[str, Any] | None = None) -> FunctionResource

Create a FunctionResource from a function.

read

read(self) -> str | bytes

Read the resource by calling the wrapped function.