saveVar / Workspace

Instructions in a transaction execute as a batch. saveVar captures an instruction’s output so later instructions can reference it.

saveVar

builder
  .callMethod(
    { componentAddress: accountAddress, methodName: "withdraw" },
    [{ Literal: resourceAddress }, { Literal: "10" }],
  )
  .saveVar("bucket");

This saves the result of the withdraw call to a workspace variable named "bucket".

Referencing workspace variables

Use { Workspace: "name" } in any argument position to reference a saved variable:

builder.callMethod(
  { componentAddress: accountAddress, methodName: "deposit" },
  [{ Workspace: "bucket" }],
);

The builder resolves string workspace names to numeric IDs internally.

Accessing tuple fields

Some methods return multiple values. You can address individual fields using .0, .1, etc.:

builder
  .callMethod(
    { componentAddress: poolComponent, methodName: "remove_liquidity" },
    [{ Workspace: "tokens_lp" }],
  )
  .saveVar("buckets")
  .callMethod(
    { componentAddress: accountAddress, methodName: "deposit" },
    [{ Workspace: "buckets.0" }],
  )
  .callMethod(
    { componentAddress: accountAddress, methodName: "deposit" },
    [{ Workspace: "buckets.1" }],
  );

Workspace references in callMethod

You can also call methods on workspace-stored components:

builder
  .callFunction({ templateAddress, functionName: "new" }, [])
  .saveVar("component")
  .callMethod(
    { fromWorkspace: "component", methodName: "init" },
    [{ Literal: "arg" }],
  );