Remove overly restrictive MIME type validation from Resource (#2585)

jlowin · web-flow · commit 0bcd69cd98a9 · 2025-12-09T20:40:00.000-05:00
diff --git a/src/fastmcp/resources/resource.py b/src/fastmcp/resources/resource.py
@@ -42,7 +42,6 @@ class Resource(FastMCPComponent):
     mime_type: str = Field(
         default="text/plain",
         description="MIME type of the resource content",
-        pattern=r"^[a-zA-Z0-9]+/[a-zA-Z0-9\-+.]+$",
     )
     annotations: Annotated[
         Annotations | None,

Original file line number	Diff line number	Diff line change
`@@ -42,7 +42,6 @@ class Resource(FastMCPComponent):`
`42`	`42`	`mime_type: str = Field(`
`43`	`43`	`default="text/plain",`
`44`	`44`	`description="MIME type of the resource content",`
`45`		`- pattern=r"^[a-zA-Z0-9]+/[a-zA-Z0-9\-+.]+$",`
`46`	`45`	`)`
`47`	`46`	`annotations: Annotated[`
`48`	`47`	`Annotations \| None,`