Silo

Interface: AgentContentBlock ​

Defined in: packages/sdk/src/agents-service.ts:590

Beta

One piece of agent-authored content — the Agent Client Protocol content block, which appears both in a streamed message chunk (AgentSessionUpdate.content) and inside a tool call's output (AgentToolCallContent.content).

type is deliberately a string, not a union. The protocol names "text", "image", "audio", "resource_link" and "resource", and a vendor may add its own; the same tolerance rule the rest of this surface follows applies — render the types you know and name, rather than drop, one you do not, so a transcript never silently loses a block.

Every field but type is optional because which ones arrive depends on the type and the agent: only "text" blocks were seen from Cursor (2026.09.02) and claude-agent-acp (0.75.1) in the 2026-09-08 probe, so treat the rest as modelled-but-unverified and check before you read.

Properties ​

type ​

ts
readonly type: string;

Defined in: packages/sdk/src/agents-service.ts:593

Beta

The protocol's block type — "text", "image", "audio", "resource_link", "resource", or a vendor's own.

text? ​

ts
readonly optional text?: string;

Defined in: packages/sdk/src/agents-service.ts:595

Beta

The text, for a "text" block.

mimeType? ​

ts
readonly optional mimeType?: string;

Defined in: packages/sdk/src/agents-service.ts:597

Beta

MIME type, for an "image" / "audio" / "resource_link" block.

uri? ​

ts
readonly optional uri?: string;

Defined in: packages/sdk/src/agents-service.ts:600

Beta

Where the content lives, for a "resource_link" (or an image given by reference rather than inline). Typically a file:// URI.

name? ​

ts
readonly optional name?: string;

Defined in: packages/sdk/src/agents-service.ts:602

Beta

A short display name, for a "resource_link".