Enum Role 

pub enum Role {
    System,
    Developer,
    User,
    Assistant,
}

The author of a message (ADR-0013).

System is the static base identity; Developer is app-author instructions that map 1:1 and losslessly onto a native provider role. On the wire, System maps to Anthropic’s top-level system (or an OpenAI system message), while Developer maps to an Anthropic mid-conversation system message (or an OpenAI developer message). Injected framing/reminders (e.g. AGENTS.md project instructions) are not Developer — they are authored as User <system-reminder> so the conversation ⇄ payload conversion stays reversible (ADR-0013 amendment / ADR-0023).

Variants

System

Immutable base identity and safety/policy — the “constitution”.

Developer

App-author instructions with a native provider role (OpenAI developer / Anthropic beta mid-conversation system). Not the vehicle for reminders — those are User.

User

The human’s turns; also carries ContentBlock::ToolResult blocks.

Assistant

The model’s turns: text, thinking, and tool-use blocks.

Trait Implementations

impl Clone for Role

fn clone(&self) -> Role

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Role

impl Debug for Role

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Role

fn deserialize<__D>( __deserializer: __D, ) -> Result<Role, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for Role

impl PartialEq for Role

fn eq(&self, other: &Role) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for Role

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Role