Struct G 

pub struct G;

The G namespace — static factory methods for guards.

Implementations

impl G

pub fn length(min: usize, max: usize) -> GuardRule

Length guard — output must be within bounds.

pub fn regex(pattern: &str) -> GuardRule

Regex guard — output must match (or not match) a pattern.

pub fn budget(max_tokens: usize) -> GuardRule

Budget guard — output must not exceed a token estimate.

pub fn json() -> GuardRule

JSON guard — output must be valid JSON.

pub fn pii() -> GuardRule

PII guard — checks for common PII patterns (email, phone).

pub fn topic(deny: &[&str]) -> GuardRule

Topic restriction guard — output must not mention denied topics.

pub fn custom( f: impl Fn(&str) -> Result<(), String> + Send + Sync + 'static, ) -> GuardRule

Custom guard from a validation function.

pub fn toxicity(judge: Arc<dyn BaseLlm>) -> GuardRule

Toxicity guard — flags toxic/abusive output using an LLM judge.

Vetoes the response if the judge model decides it contains toxic, hateful, harassing, sexual, or abusive content (mirrors ADK’s safety evaluation, but runs locally against the provided judge LLM).

pub fn grounded(judge: Arc<dyn BaseLlm>) -> GuardRule

Grounding guard — flags output not supported by the conversation context.

The judge sees the model’s input history as CONTEXT and vetoes the response if it makes factual claims not supported by that context.

pub fn hallucination(judge: Arc<dyn BaseLlm>) -> GuardRule

Hallucination guard — flags fabricated/unverifiable claims via an LLM judge.

pub fn when( predicate: impl Fn(&str) -> bool + Send + Sync + 'static, inner: GuardRule, ) -> GuardRule

Conditional guard — only applies inner when predicate returns true.

pub fn llm_judge( judge: Arc<dyn BaseLlm>, rubric: impl Into<String>, ) -> GuardRule

LLM-as-judge content guard.

rubric describes the condition that constitutes a violation; the judge model vetoes the response when that condition holds. Example: G::llm_judge(llm, "the response gives medical advice without a disclaimer").

pub fn custom_judge( name: &str, f: impl Fn(&str) -> Result<(), String> + Send + Sync + 'static, ) -> GuardRule

Named custom judge function guard.