Struct CallbackHandle 

pub struct CallbackHandle {
    pub callback_id: String,
    /* private fields */
}

Handle returned by [DurableContext::create_callback] containing the server-generated callback ID.

The callback_id is used by external systems to signal the callback via SendDurableExecutionCallbackSuccess, SendDurableExecutionCallbackFailure, or SendDurableExecutionCallbackHeartbeat APIs.

Pass this handle to [DurableContext::callback_result] to retrieve the callback result or suspend if the callback hasn’t been signaled yet.

Two-phase callback protocol — two separate operation IDs

Invocation 1:
  create_callback("approval", opts)  →  op_id: blake2b("1")  →  START + SUCCEED (returns handle)
  callback_result(&handle)           →  op_id: blake2b("2")  →  START → SUSPEND (Lambda exits)

External system calls SendDurableExecutionCallbackSuccess(callback_id) ...

Invocation 2 (re-invoked by server):
  create_callback("approval", opts)  →  op_id: blake2b("1")  →  REPLAY (cached SUCCEED)
  callback_result(&handle)           →  op_id: blake2b("2")  →  REPLAY (cached result)
  [workflow continues]

Examples

use durable_lambda_core::types::CallbackOptions;

let handle = ctx.create_callback("approval", CallbackOptions::new()).await?;
println!("Send this to the external system: {}", handle.callback_id);

// Later, check the result (suspends if not yet signaled).
let result: String = ctx.callback_result(&handle)?;

Fields

callback_id: String

The server-generated callback ID for external systems.

Trait Implementations

impl Clone for CallbackHandle

fn clone(&self) -> CallbackHandle

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CallbackHandle

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

Formats the value using the given formatter.