Struct SystemPrompt 

pub struct SystemPrompt {
    pub cacheable: String,
    pub dynamic: String,
}

Structured system prompt split into cacheable and dynamic sections.

Anthropic automatically caches the longest matching prefix of the system prompt across turns. By placing stable content first (cacheable) and per-turn content after (dynamic), we get ~75% token savings on cache hits.

Fields

cacheable: String

Stable across turns — gets Anthropic prompt cache hits.

dynamic: String

Changes per turn — always re-sent fresh.

Implementations

impl SystemPrompt

pub fn combined(&self) -> String

Combine both sections into a single prompt string (backward compatible).

Trait Implementations

impl Clone for SystemPrompt

fn clone(&self) -> SystemPrompt

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SystemPrompt

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

Formats the value using the given formatter.