Enum ContentBlock 

pub enum ContentBlock {
    Text(String),
    Image {
        data: String,
        mime_type: String,
    },
    Audio {
        data: String,
        mime_type: String,
    },
    ResourceLink {
        uri: String,
        name: Option<String>,
        description: Option<String>,
        mime_type: Option<String>,
    },
    Resource {
        uri: String,
        mime_type: Option<String>,
        text: Option<String>,
        blob: Option<String>,
    },
}

A content block in an MCP tool result. Per the 2025-11-25 spec, servers may return text, image, audio, resource_link (URI reference), or embedded resource content. Older servers only emit text/image.

Variants

Text(String)

Image

Fields

data: String

mime_type: String

Audio

Audio content — base64-encoded data + mime type (e.g., audio/wav). Routed to the model’s image attachment channel for now; adapters that don’t support audio will silently drop the bytes but keep the text hint from the tool output.

Fields

data: String

mime_type: String

ResourceLink

URI reference to an external resource. Rendered as text for the model so it can follow up with another tool call if needed.

Fields

uri: String

name: Option<String>

description: Option<String>

mime_type: Option<String>

Resource

Embedded resource — same shape as a read_resource response. Either text or blob (base64) is present depending on the resource’s kind. Rendered as text for the model.

Fields

uri: String

mime_type: Option<String>

text: Option<String>

blob: Option<String>

Trait Implementations

impl Clone for ContentBlock

fn clone(&self) -> ContentBlock

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ContentBlock

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.