Tutorial: Your First Gate

Goal: Prove one tiny thing.

Outcome: The run only passes when the live claim holds.

---

Do this: create one tiny proof file.

import { Effect } from "effect";
import {
  Act,
  Assert,
  Gate,
  Plan,
  createHttpObserveResource,
  type ScopeFile,
} from "../../src/index";
import { HELLO_WORLD_PORT } from "./server";

const baseUrl = `http://127.0.0.1:${HELLO_WORLD_PORT}`;

const scope = {
  spec: {
    title: "Hello World",
    tutorial: {
      goal: "Prove one tiny thing.",
      outcome: "The run only passes when the live response says hello world.",
    },
    howTo: {
      task: "Run one complete gate from one file.",
      done: "The endpoint returns 200 and the body contains hello world.",
    },
    explanation: {
      summary: "Even the smallest run is still a real proof loop.",
    },
  },
  plan: Plan.define({
    goals: [
      {
        id: "hello-world",
        title: "GET / returns hello world",
        gate: Gate.define({
          observe: createHttpObserveResource({
            url: `${baseUrl}/`,
          }),
          act: [Act.exec(`curl -sf ${baseUrl}/`)],
          assert: [
            Assert.httpResponse({ status: 200 }),
            Assert.responseBodyIncludes("hello world"),
            Assert.noErrors(),
          ],
        }),
      },
    ],
    loop: {
      maxIterations: 1,
      stopOnFailure: true,
    },
  }),
} satisfies ScopeFile;

export default scope;

if (import.meta.main) {
  const result = await Effect.runPromise(Plan.runLoop(scope.plan));
  console.log(JSON.stringify(result, null, 2));

  if (result.status !== "pass") {
    process.exitCode = 1;
  }
}

Run it:

bun run example:hello-world

The loop passes only when the live response matches the claim. One file, one gate, one pass.