---
title: "Browser handoff leases"
description: "Give one authenticated person temporary control on the exact merchant origin."
image: "https://help.agent.mq/og.svg"
---

> Documentation Index
> Fetch the complete documentation index at: https://help.agent.mq/llms.txt
> Use this file to discover all available pages before exploring further.

# Browser handoff leases

A handoff is an exclusive lease on human control, not a credential handoff. One row per purchase records the holder, allowed merchant origin, expiry, and revision.

1. **Claim the lease**

   `POST /v1/applications/{appId}/purchases/{purchaseId}/handoffs` accepts an empty JSON object. A claim is refused while another holder's lease is live.
2. **Read the allowed origin and expiry**

   `GET /v1/applications/{appId}/purchases/{purchaseId}/handoffs/{handoffId}` returns the redacted lease.
3. **Release it**

   The holder calls `/complete` after finishing the human step, or `/cancel` to return control without completing it. Both writes echo `expectedRevision`.

## Verify

A non-holder cannot release the lease. Claims are blocked after the payment commit boundary, and an active lease is revoked when the purchase is cancelled or begins its single payment attempt.

## Next steps

- [Purchase state model](/agentic-purchases/state-model)
- [Security and contact](/help/security)

Source: https://help.agent.mq/agentic-purchases/handoffs/index.mdx