agent_core

Crate: agent_core · Path: crates/agent_core
Description (Cargo.toml): Protocol-agnostic agent domain types — the universal vocabulary for messages, tasks, and artifacts independent of A2A, MCP, or any wire protocol

Role

Defines the universal vocabulary for agent interactions — messages, content parts, task phases, and conversation context — without any dependency on A2A, MCP, or any specific wire protocol. Consumers that only need to describe agent interactions (studio, coordination, tests) depend on agent_core alone. The agent_sdk crate provides bidirectional conversions between these types and protocol-specific types.

Feature flags

This crate has no feature flags. It depends only on serde and serde_json.

Public API (from `src/lib.rs`)

From src/message.rs (re-exported via pub use message::*):

Role — enum: User, Agent, System
ContentPart — enum: Text(String), File { uri, mime, data }, Data(serde_json::Value)
AgentMessage — struct with role and parts; convenience constructors user_text(), agent_text(), system_text(); helpers text_content(), is_text_only(), has_data()

From src/task.rs (re-exported via pub use task::*):

TaskPhase — enum: Pending, Working, Completed, Failed, Cancelled
ConversationContext — struct with history: Vec<AgentMessage>, task_phase, metadata; constructors new(), from_text_turns()

Example sketch

use agent_core::{AgentMessage, Role, ContentPart, ConversationContext};

// Simple text message
let msg = AgentMessage::user_text("What's the weather?");
assert_eq!(msg.role, Role::User);

// Structured content
let msg = AgentMessage::new(Role::User, vec![
    ContentPart::Text("Analyze this data".into()),
    ContentPart::Data(serde_json::json!({"rows": 42})),
]);

// Conversation context from text turns
let ctx = ConversationContext::from_text_turns(&[
    ("user", "hello"),
    ("assistant", "hi there"),
]);
assert!(ctx.has_history());

Full API reference: cargo doc -p agent_core --no-deps