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Chaos Maker

Seeded Reproducibility

Every probability roll inside Chaos Maker flows through a seeded PRNG. With the same seed and the same interaction sequence, Chaos Maker emits the same sequence of ChaosEvent decisions.

await injectChaos(page, {
  seed: 12345,
  network: {
    failures: [{ urlPattern: '/api/orders', statusCode: 503, probability: 0.5 }],
  },
});

Auto-generated seeds

Section titled “Auto-generated seeds”

When seed is omitted, Chaos Maker auto-generates a 32-bit seed during instance creation. Read it from the adapter and print it on failure.

const seed = await getChaosSeed(page);
console.info('Replay with seed:', seed);

Boundaries

Section titled “Boundaries”

Seeds control Chaos Maker decisions. They do not freeze browser scheduling, server timing, wall-clock timestamp fields, or nondeterminism in the application under test. For replay, drive the same user actions in the same order.