# Vaults.fyi Idle Assets Balance Lookup

> Vaults.fyi Idle Assets Balance Lookup is a paid API for AI agents from api.vaults.fyi, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-11).

Returns the balances of idle (uninvested) assets for a specific user wallet address across supported DeFi vaults.

## Facts

- Endpoint: HEAD https://api.vaults.fyi/v2/portfolio/idle-assets/:userAddress?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vaults-fyi-idle-assets-balance-lookup-aeb3e6c8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0xjLrI7EBB_9yffzIm3r-

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability vaults-fyi-idle-assets-balance-lookup-aeb3e6c8 -d '<json body>'
```

Example prompt: Can you check what idle assets I have sitting uninvested for my wallet address 0x1234abcd...? I want to see which tokens aren't currently earning yield in any vault.

## When to prefer this

Use this endpoint when you need to identify uninvested or idle assets for a specific wallet address — particularly useful before recommending vault deposits or performing portfolio yield-gap analysis. Prefer this over general portfolio endpoints when the specific goal is to surface undeployed capital rather than active vault positions or returns.

## Known failure modes

- Invalid or malformed wallet address returns an error
- Unsupported blockchain address format
- Address with no activity or zero balances may return empty results
- Rate limiting or payment failure if x402 payment header is missing or insufficient
- Network timeouts for addresses with large transaction histories

## How this service works

Get balances of idle assets for a specific user address.

## Output

A breakdown of the user's idle (uninvested) asset balances for the given wallet address, including token types and amounts that are currently not deposited in any yield-generating vault.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vaults-fyi-idle-assets-balance-lookup-aeb3e6c8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vaults.fyi](https://www.zero.xyz/host/api.vaults.fyi/llms.txt)