> ## Documentation Index > Fetch the complete documentation index at: https://docs.darwin.so/llms.txt > Use this file to discover all available pages before exploring further. # Top Up > Return a linked user to Darwin to fund the Agent Wallet securely. A Connect application cannot retrieve or reuse a linked user's saved Darwin payment method. When goal approval returns `funding_required`, open the Darwin-hosted owner flow for the affected agent and authorization. After the user completes or exits the flow, read the authoritative goal and wallet state. Retry the blocked approval idempotently only after Darwin confirms sufficient available funds. Do not ask the user for card details in your interface on Darwin's behalf, copy a payment token from another processor, or optimistically increase the displayed balance. App-funded ephemeral work uses the application's operational balance instead of this linked-user flow. Understand manual funding, auto top-up, and failure states.