`fastmcp.resources.template`

Resource template functionality.

Functions

`extract_query_params`

extract_query_params(uri_template: str) -> set[str]

Extract query parameter names from RFC 6570 {?param1,param2} syntax.

`build_regex`

build_regex(template: str) -> re.Pattern[str] | None

Build regex pattern for URI template, handling RFC 6570 syntax. Supports:

{var} - simple path parameter
{var*} - wildcard path parameter (captures multiple segments)
{?var1,var2} - query parameters (ignored in path matching)

Hyphens in parameter names are normalized to underscores in regex group names so that matched groups are valid Python identifiers. Returns None if the template produces an invalid regex (e.g. parameter names with leading digits or duplicates from a remote server).

`match_uri_template`

match_uri_template(uri: str, uri_template: str) -> dict[str, str] | None

Match URI against template and extract both path and query parameters. Supports RFC 6570 URI templates:

Path params: {var}, {var*}
Query params: {?var1,var2}

`expand_uri_template`

expand_uri_template(uri_template: str, params: dict[str, Any]) -> str

Expand a URI template with parameters — inverse of match_uri_template. Supports the same RFC 6570 subset:

Path params: {var}, {var*}
Query params: {?var1,var2}

Classes

`ResourceTemplate`

A template for dynamically creating resources. Methods:

`resolve_security`

resolve_security(self, server_default: ResourceSecurity | None) -> ResourceSecurity | None

Resolve the effective security policy for this template. A per-component security overrides the server default. INHERIT_SECURITY (the field default) inherits server_default; an explicit None disables screening for this template.

`from_function`

from_function(fn: Callable[..., Any], uri_template: str, name: str | None = None, version: str | int | None = None, title: str | None = None, description: str | None = None, icons: list[Icon] | None = None, mime_type: str | None = None, tags: set[str] | None = None, annotations: Annotations | None = None, meta: dict[str, Any] | None = None, auth: AuthCheck | list[AuthCheck] | None = None, security: ResourceSecurity | None | InheritSecurity = INHERIT_SECURITY) -> FunctionResourceTemplate

`set_default_mime_type`

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

Set default MIME type if not provided.

`matches`

matches(self, uri: str) -> dict[str, Any] | None

Check if URI matches template and extract parameters.

`read`

read(self, arguments: dict[str, Any]) -> str | bytes | ResourceResult

Read the resource content.

`convert_result`

convert_result(self, raw_value: Any) -> ResourceResult

Convert a raw result to ResourceResult. This is used in two contexts:

In _read() to convert user function return values to ResourceResult
In tasks_result_handler() to convert Docket task results to ResourceResult

Handles ResourceResult passthrough and converts raw values using ResourceResult’s normalization. The template’s own mime_type is forwarded so that reads match the MIME type the template advertises in resources/templates/list.

`create_resource`

create_resource(self, uri: str, params: dict[str, Any]) -> Resource

Create a resource from the template with the given parameters. The base implementation does not support background tasks. Use FunctionResourceTemplate for task support.

`to_mcp_template`

to_mcp_template(self, **overrides: Any) -> SDKResourceTemplate

Convert the resource template to an SDKResourceTemplate.

`from_mcp_template`

from_mcp_template(cls, mcp_template: SDKResourceTemplate) -> ResourceTemplate

Creates a FastMCP ResourceTemplate from a raw MCP ResourceTemplate object.

`key`

key(self) -> str

The globally unique lookup key for this template.

`get_span_attributes`

get_span_attributes(self) -> dict[str, Any]

`FunctionResourceTemplate`

A template for dynamically creating resources. Methods:

`create_resource`

create_resource(self, uri: str, params: dict[str, Any]) -> Resource

Create a resource from the template with the given parameters.

`read`

read(self, arguments: dict[str, Any]) -> str | bytes | ResourceResult

Read the resource content.

`from_function`

from_function(cls, fn: Callable[..., Any], uri_template: str, name: str | None = None, version: str | int | None = None, title: str | None = None, description: str | None = None, icons: list[Icon] | None = None, mime_type: str | None = None, tags: set[str] | None = None, annotations: Annotations | None = None, meta: dict[str, Any] | None = None, auth: AuthCheck | list[AuthCheck] | None = None, security: ResourceSecurity | None | InheritSecurity = INHERIT_SECURITY) -> FunctionResourceTemplate

Create a template from a function.

fastmcp.apps

fastmcp.experimental