fastmcp.resources.template

Resource template functionality.

Functions

extract_query_params ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L38" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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

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

build_regex ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L46" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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 ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L83" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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 ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L122" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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 href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L170" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

A template for dynamically creating resources.

Methods:

resolve_security ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L203" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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 ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L220" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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 ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L253" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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

Set default MIME type if not provided.

matches ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L259" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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

Check if URI matches template and extract parameters.

read ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L263" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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

Read the resource content.

convert_result ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L269" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

convert_result(self, raw_value: Any) -> ResourceResult

Convert a raw result to ResourceResult.

This is used in two contexts:

1. In _read() to convert user function return values to ResourceResult
2. 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 ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L296" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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 ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L307" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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

Convert the resource template to an SDKResourceTemplate.

from_mcp_template ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L327" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

from_mcp_template(cls, mcp_template: SDKResourceTemplate) -> ResourceTemplate

Creates a FastMCP ResourceTemplate from a raw MCP ResourceTemplate object.

key ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L340" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

key(self) -> str

The globally unique lookup key for this template.

get_span_attributes ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L345" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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

FunctionResourceTemplate ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L352" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

A template for dynamically creating resources.

Methods:

create_resource ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L367" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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

Create a resource from the template with the given parameters.

read ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L389" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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

Read the resource content.

from_function ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/resources/template.py#L429" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

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.