Readback

Readback is an agent for long, multi-step jobs that cross systems and people it does not control. It never marks a step done until a second source confirms it. Every step is a document in MongoDB Atlas whose validator rejects “verified” without evidence. After a crash the worker checks the outside system by its own reference before it resends, so nothing is done twice. A LangGraph planner (observe, plan, guard) proposes each move and can hold an irreversible step when something a person says raises a risk; it can never mark anything verified. Past failures live in Atlas Vector Search with automated embedding and become preconditions on the next job. When a step depends on a phone call, an ElevenLabs voice agent makes it, repeats back what it heard, and code checks the answer against the original request. The demo applies this to one job: a supplier wire payment. Killed mid-submission, the agent restarts and leaves one wire at the bank, not two. On the call, a wrong digit read back by the bank is caught before release. A person approves the release, and the supplier’s receipt, picked up by a change stream, closes the case. The same core fits any work where “done” is something a person or another system told you: insurance claims, vendor onboarding, permit applications, refunds, purchase orders. The bank portal and all data in the demo are a test rig built today.