Module agent 

agent

Agent loop domain types.

These types define the core abstractions for the backend agentic loop. They are pure domain primitives: no LLM backend references, no MCP types, no infrastructure concerns.

Modules

Module	Contents
config	AgentConfig — loop control parameters
tool_types	ToolDefinition, ToolCall, ToolResult
messages	AgentMessage — closed conversation-turn enum
messages_serde	Custom Serialize/Deserialize impls for AssistantContent
events	AgentEvent (SSE units), LlmStreamEvent (stream protocol)

Design Principles

• AgentMessage is a closed enum so the type system prevents invalid states (e.g. a User message carrying tool_calls).
• ToolDefinition is a dedicated type — adapter layers convert McpTool → ToolDefinition; the agent domain must not depend on MCP domain types.
• ToolResult with success: false is context for the LLM, not an error; tool failures are fed back into the conversation so the model can reason about them and retry or adjust its approach.
• AgentEvent is the unit of SSE emission; every observable state change in the loop corresponds to exactly one variant.

Modules

Module	LOC	Complexity	Coverage
config.rs
events.rs
messages.rs
messages_serde.rs
tool_display.rs
tool_types.rs

Re-exports

pub use config::AgentConfig;

pub use config::AgentConfigError;

pub use config::DEFAULT_MAX_ITERATIONS;

pub use config::DEFAULT_MAX_PARALLEL_TOOLS;

pub use config::DEFAULT_MAX_STAGNATION_STEPS;

pub use config::MAX_ITERATIONS_CEILING;

pub use config::MAX_PARALLEL_TOOLS_CEILING;

pub use config::MAX_TOOL_TIMEOUT_MS_CEILING;

pub use config::MIN_CONTEXT_BUDGET_CHARS;

pub use config::MIN_TOOL_TIMEOUT_MS;

pub use events::AGENT_EVENT_CHANNEL_CAPACITY;

pub use events::AgentEvent;

pub use events::LlmStreamEvent;

pub use messages::AgentMessage;

pub use messages::AssistantContent;

pub use tool_types::ToolCall;

pub use tool_types::ToolDefinition;

pub use tool_types::ToolResult;

Modules

config

AgentConfig — configuration for a single agentic loop run.

events

AgentEvent and LlmStreamEvent — observable events in the agentic loop.

messages

AgentMessage — A single message in the agent conversation.

messages_serde 🔒

Custom Serialize / Deserialize implementations for agent message types.

tool_display

Shared tool display formatting — single source of truth for all surfaces.

tool_types

Tool-schema and tool-call/result types.