Orch8 vs Temporal

Temporal: event replay

Temporal stores every event (step started, step completed, timer fired, signal received) in a history log. On recovery, it replays the entire history to reconstruct the workflow state.

Where this excels:

• + Full audit trail with every event preserved
• + Complete Event History supports replay-based diagnosis and state reconstruction
• + Durable workflow state and deterministic recovery semantics

Trade-offs to consider:

• → History grows with every event — long-running workflows (days/weeks) accumulate large histories
• → History growth and replay behavior must be managed with Temporal's continuation and versioning mechanisms
• → Workflow code must be deterministic — no direct API calls, no timestamps, no random values in workflow functions

Orch8: state snapshots

Orch8 persists the full execution state (current position, step outputs, context) as a snapshot after each step. On recovery, it loads the snapshot and resumes from the last completed step.

Where this excels:

• + Recovery resumes from persisted execution state without replaying user workflow code from the beginning
• + No determinism constraints — handlers are plain HTTP endpoints
• + Ideal for workflows that run for days or weeks (campaigns, monitoring, agents)

Trade-offs to consider:

• → Checkpoint-oriented debugging is bounded to retained state and redacted diffs; it is not a replayable history of every workflow event
• → Effect receipts, provenance, audit records, and checkpoint evidence cover engine decisions; handler-internal events still require application telemetry

Temporal — workflow code with determinism constraints

1// Temporal workflow — must be deterministic
2async function onboardingWorkflow(user: User) {
3  // Cannot call APIs directly in workflow code.
4  // Must use activities (separate functions):
5  await activities.sendWelcomeEmail(user);
6
7  // Cannot use Date.now() — must use workflow time:
8  await workflow.sleep('3 days');
9
10  // Cannot use Math.random() — must use deterministic
11  // alternatives for A/B testing
12  await activities.sendFollowUp(user);
13}

Orch8 — JSON definition with plain handlers

1// Orch8 — no determinism constraints
2// Handlers are plain HTTP endpoints:
3app.post('/workers/send_welcome', async (req, res) => {
4  // Call APIs directly. Use Date.now(). Use Math.random().
5  // Use a provider idempotency key: a crash can occur after
6  // the provider accepts the effect but before completion commits.
7  const result = await sendEmail({
8    to: req.body.context.data.email,
9    template: 'welcome',
10  });
11  res.json({ sent: true, id: result.id });
12});