Type Safety & Validation
End-to-end TypeScript inference with automatic runtime validation using Zod, Valibot, or ArkType.
temporal-contractType-safe contracts for Temporal.io
End-to-end type safety · Runtime validation · Explicit error handling
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Explicit Error Handling
Result/AsyncResult pattern from unthrown for workflows that need explicit error handling without exceptions.
Contract-First Design
Define your workflow interface once — types and validation flow from contract to client and worker.
Quick Example
Define your contract once — get type safety everywhere:
typescript
import { defineContract } from "@temporal-contract/contract";
import { z } from "zod";
export const orderContract = defineContract({
taskQueue: "orders",
workflows: {
processOrder: {
input: z.object({
orderId: z.string(),
customerId: z.string(),
amount: z.number(),
}),
output: z.object({
status: z.enum(["success", "failed"]),
transactionId: z.string().optional(),
}),
activities: {
processPayment: {
input: z.object({ customerId: z.string(), amount: z.number() }),
output: z.object({ transactionId: z.string() }),
},
sendNotification: {
input: z.object({ customerId: z.string(), message: z.string() }),
output: z.void(),
},
},
},
},
});typescript
import { fromPromise } from "unthrown";
import { declareActivitiesHandler, ApplicationFailure } from "@temporal-contract/worker/activity";
import { orderContract } from "./contract.js";
export const activities = declareActivitiesHandler({
contract: orderContract,
activities: {
processOrder: {
processPayment: ({ customerId, amount }) =>
fromPromise(paymentService.charge(customerId, amount), (e) =>
ApplicationFailure.create({
type: "PAYMENT_FAILED",
message: e instanceof Error ? e.message : "Payment failed",
cause: e instanceof Error ? e : undefined,
}),
).map((tx) => ({ transactionId: tx.id })),
sendNotification: ({ customerId, message }) =>
fromPromise(notificationService.send(customerId, message), (e) =>
ApplicationFailure.create({
type: "NOTIFICATION_FAILED",
message: e instanceof Error ? e.message : "Notification failed",
cause: e instanceof Error ? e : undefined,
}),
),
},
},
});typescript
import { declareWorkflow } from "@temporal-contract/worker/workflow";
import { orderContract } from "./contract.js";
export const processOrder = declareWorkflow({
workflowName: "processOrder",
contract: orderContract,
activityOptions: { startToCloseTimeout: "1 minute" },
implementation: async ({ activities }, { orderId, customerId, amount }) => {
const { transactionId } = await activities.processPayment({ customerId, amount });
await activities.sendNotification({ customerId, message: `Order ${orderId} confirmed!` });
return { status: "success", transactionId };
},
});typescript
import { TypedClient } from "@temporal-contract/client";
import { Connection, Client } from "@temporalio/client";
import { orderContract } from "./contract.js";
const connection = await Connection.connect({ address: "localhost:7233" });
const temporalClient = new Client({ connection });
const client = await TypedClient.create({
contract: orderContract,
client: temporalClient,
}).getOrThrow();
const future = client.executeWorkflow("processOrder", {
workflowId: "order-123",
args: { orderId: "ORD-123", customerId: "CUST-456", amount: 99.99 },
});
const result = await future;
result.match({
ok: (output) => console.log(output.status), // ✅ 'success' | 'failed'
err: (error) => console.error("Failed:", error),
defect: (cause) => console.error("Unexpected:", cause),
});