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Time-travel

Return to any pressed Seal and let history run again — without erasing what happened the first time.

Every superstep leaves a Seal; seal_id resumes from any of them:

seals = await codex.list("inv-1")
replay = await rite.ainvoke(invocation_id="inv-1",
                            seal_id=seals[1].seal_id)

The semantics (stable since v0.1.0)

  • A Seal restores historic state. Its Aether is what the world looked like at that superstep — not what it became later. Resuming from a Seal written before some fact arrived replays the run without that fact. In particular, resuming from an interrupt Seal will interrupt again unless you inject the awaited data.

  • Combine seal_id with updates to change history deliberately:

    python replay = await rite.ainvoke( invocation_id="inv-1", seal_id=seals[1].seal_id, updates={"approved": True}, # what-if: approve at superstep 1 )

  • Histories are append-only. A replay appends its new Seals after the old ones instead of rewriting them; codex.get() returns the most recently written Seal. The audit trail stays honest — you can see both the original run and every replay.

  • The superstep counter resumes from the Seal, and recursion_limit applies to the Invocation's total — long histories with many replays may need a higher limit at compile().

Typical uses: debugging an agent's wrong turn by replaying from just before it, A/B-ing a prompt change from a mid-run Seal, and recovering a crashed pipeline from the last valid checkpoint (see resilience policies — failed supersteps never write a Seal, so the latest Seal is always consistent).