Struct RunnableConfigurable 

pub struct RunnableConfigurable<I: Send + Sync + 'static, O: Send + Sync + 'static> { /* private fields */ }

Routes between a default runnable and named alternatives at invoke time.

The selector key (which) is read from config.configurable; the value must be a string naming either the default_key (→ default) or one of the alternatives. An unknown value falls back to the default.

Example

let chain = llm.configurable_alternatives(
    "provider", "default",
    vec![("anthropic", anthropic_llm), ("ollama", ollama_llm)],
);
// config = RunnableConfig::new().with_configurable("provider", json!("anthropic"))

Implementations

impl<I: Send + Sync + 'static, O: Send + Sync + 'static> RunnableConfigurable<I, O>

pub fn new<R>( default: R, which: impl Into<String>, default_key: impl Into<String>, ) -> Self

where R: Runnable<I, O> + 'static, R::Error: Into<LcelError>,

Build a configurable router.

• default — runnable used when the selector is absent, equals default_key, or names an unknown alternative.
• which — key read from config.configurable.
• default_key — config value that routes to default.
• alternatives — (option name, runnable) pairs; the config value must match one of these names to be selected.

pub fn with_alternative<R>(self, name: impl Into<String>, runnable: R) -> Self

where R: Runnable<I, O> + 'static, R::Error: Into<LcelError>,

Add an alternative branch reachable via config.configurable[which] == name.

Trait Implementations

impl<I: Send + Sync + 'static, O: Send + Sync + 'static> Debug for RunnableConfigurable<I, O>

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

Formats the value using the given formatter.

impl<I: Send + Sync + 'static, O: Send + Sync + 'static> Runnable<I, O> for RunnableConfigurable<I, O>

type Error = LcelError

Error type.

fn invoke<'life0, 'async_trait>( &'life0 self, input: I, config: Option<RunnableConfig>, ) -> Pin<Box<dyn Future<Output = Result<O, LcelError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Transforms single input to output.

fn batch<'life0, 'async_trait>( &'life0 self, inputs: Vec<I>, config: Option<RunnableConfig>, ) -> Pin<Box<dyn Future<Output = Result<Vec<O>, LcelError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Batch processing - transforms multiple inputs to outputs.

fn stream<'life0, 'async_trait>( &'life0 self, input: I, config: Option<RunnableConfig>, ) -> Pin<Box<dyn Future<Output = Result<Pin<Box<dyn Stream<Item = Result<O, LcelError>> + Send>>, LcelError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Streaming output - for real-time responses (LLM, etc).

fn transform<'life0, 'async_trait>( &'life0 self, input: Pin<Box<dyn Stream<Item = Result<I, LcelError>> + Send>>, config: Option<RunnableConfig>, ) -> Pin<Box<dyn Future<Output = Result<Pin<Box<dyn Stream<Item = Result<O, LcelError>> + Send>>, LcelError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Stream-to-stream transformation - the core of LCEL streaming.

fn batch_as_completed<'life0, 'async_trait>( &'life0 self, inputs: Vec<Input>, config: Option<RunnableConfig>, ) -> Pin<Box<dyn Future<Output = Result<Vec<(usize, Output)>, Self::Error>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Batch processing that returns results in completion order.