v0.12.1

Restate Rust SDK v0.12.1 Release Notes

Highlights

• Scoped ingress clients — bind a generated ingress client to a Restate Cloud scope once, instead of threading a .scope(...) call through every request
• Workflow handle lookup — re-attach to a running workflow by key alone with the new handle() method on generated workflow ingress clients, no need to persist the invocation ID

Table of Contents

• New Features
  • Scoped ingress clients and workflow handle lookup

New Features

Scoped ingress clients and workflow handle lookup

Generated ingress clients gain two additions:

• scoped_client(...) — an alternative constructor (alongside from_client) that binds the
  client to a Restate Cloud scope. Every request issued by a scoped client (and its workflow
  handle() lookup) is routed through the /restate/scope/{scope}/... prefix.
• Workflow handle() — generated workflow ingress clients expose an async handle() method
  that resolves the InvocationHandle for the workflow invocation keyed by the client's key. The
  handle is typed to the workflow's run handler output, so attach()/output() decode that
  result. If a workflow declares a handler literally named handle, its generated method is renamed
  to _handle so the injected lookup keeps the plain handle name (the on-the-wire handler name is
  unchanged).

At the transport level, Client::lookup_workflow(workflow_name, workflow_key, scope) is now public.
It resolves a workflow invocation to a typed InvocationHandle through the /restate/lookup route.

Why this matters:

• Restate Cloud users can target a specific scope from a single Client without threading a
  .scope(...) call through every request.
• Workflows can be re-attached from outside a Restate service by key alone, without having to
  persist the invocation ID returned at submission time.

Impact on users:

• No breaking changes; these are purely additive APIs.
• handle() and lookup_workflow require Restate >= 1.7 (the /restate/lookup route).
• Scoped routing requires Restate Cloud.

Example:

use restate_sdk::ingress::ReqwestClient;

let client = ReqwestClient::connect("http://localhost:8080".parse()?)?;

// Submit a workflow, then re-attach to it later by key.
let workflow = MyWorkflowIngressClient::from_client(client.clone(), "order-42");
workflow.run("input".to_owned()).send().await?;

let handle = workflow.handle().await?;
let result = handle.attach().await?.into_body();

// Scoped client: every request runs in the given Restate Cloud scope.
let scoped = MyWorkflowIngressClient::scoped_client(client, "order-42", "prod");

Related Issues:

• PR #129