Expense Approval

1import { LoopBuilder } from "@loop-engine/sdk"
2 
3const approval = LoopBuilder
4  .create("expense.approval", "finance")
5  .description("Expense report approval")
6  .state("SUBMITTED")
7  .state("UNDER_REVIEW")
8  .state("APPROVED", { isTerminal: true })
9  .state("REJECTED", { isTerminal: true })
10  .initialState("SUBMITTED")
11  .transition({ id: "start_review", from: "SUBMITTED", to: "UNDER_REVIEW", actors: ["automation"] })
12  .transition({
13    id: "approve",
14    from: "UNDER_REVIEW",
15    to: "APPROVED",
16    actors: ["human"],
17    guards: [
18      {
19        id: "approval_obtained" as never,
20        description: "Manager approval required",
21        failureMessage: "Approval missing",
22        severity: "hard",
23        evaluatedBy: "runtime"
24      }
25    ]
26  })
27  .transition({ id: "reject", from: "UNDER_REVIEW", to: "REJECTED", actors: ["human"] })
28  .outcome({ id: "expense_approved", description: "Expense approved", valueUnit: "expense_approved" })
29  .build()

1import { aggregateId, transitionId } from "@loop-engine/core"
2import { createLoopSystem } from "@loop-engine/sdk"
3 
4const aggregate = aggregateId("EXP-2026-001")
5const { engine } = await createLoopSystem({ loops: [approval] })
6 
7await engine.start({
8  loopId: "expense.approval",
9  aggregateId: aggregate,
10  orgId: "acme",
11  actor: { type: "system", id: "system:intake" }
12})
13 
14await engine.transition({
15  aggregateId: aggregate,
16  transitionId: transitionId("start_review"),
17  actor: { type: "automation", id: "system:router" }
18})

1const passed = await engine.transition({
2  aggregateId: aggregate,
3  transitionId: transitionId("approve"),
4  actor: { type: "human", id: "manager@acme.com" },
5  evidence: { approved: true }
6})
7"cmt">// passed.status === "executed"
8 
9const failed = await engine.transition({
10  aggregateId: aggregate,
11  transitionId: transitionId("approve"),
12  actor: { type: "human", id: "manager@acme.com" },
13  evidence: { approved: false }
14})
15"cmt">// failed.status === "guard_failed"