Struct Backend 

pub struct Backend<C: LLMClient> {
    pub client: C,
    pub cost_per_1m: Option<(f64, f64)>,
    pub priority: usize,
    /* private fields */
}

A single backend in a RouterClient chain.

cost_per_1m is the (input, output) price per 1,000,000 tokens in USD, used by RoutingStrategy::LowestCost to order backends. priority (ascending) is used by RoutingStrategy::Fallback. Ties in either keep insertion order (stable sort).

Fields

client: C

The underlying client.

cost_per_1m: Option<(f64, f64)>

(input_per_1m, output_per_1m) in USD. None = unknown → sorts last.

priority: usize

Lower = tried first. Defaults to 0.

Implementations

impl<C: LLMClient> Backend<C>

pub fn new(client: C, cost_per_1m: Option<(f64, f64)>) -> Self

Create a backend with no cost metadata and default priority.

pub fn with_priority(self, priority: usize) -> Self

Set the fallback priority (lower = tried first).

pub fn with_label(self, label: impl Into<String>) -> Self

Override the label used for this backend (otherwise the underlying client’s LLMClient::model_name is used).