# Alchemy Portfolio API — Multi-Chain NFT Holdings by Wallet Address

> Alchemy Portfolio API — Multi-Chain NFT Holdings by Wallet Address is a paid API for AI agents from x402.alchemy.com, paid per call via x402, $0.001000/call, status unknown (last checked 2026-10-11).

Returns all NFT holdings across multiple blockchains for one or more wallet addresses in a single call.

## Facts

- Endpoint: POST https://x402.alchemy.com/data/v1/assets/nfts/by-address?utm_source=zero.xyz
- Price: $0.001000/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/alchemy-0a0be618
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_EWnrmSQ4HBvBH3y0f2ixg

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 alchemy-0a0be618 -d '<json body>'
```

Example prompt: Show me all the NFTs held by wallet 0x71C7656EC7ab88b098defB751B7401B5f6d8976F across every supported chain — Ethereum, Polygon, and any others Alchemy tracks.

## When to prefer this

Use this endpoint when you need a unified, multi-chain view of NFT holdings for one or more wallet addresses without having to query each blockchain separately. It is ideal for portfolio dashboards, wallet analytics, cross-chain asset discovery, and any use case where the user's NFTs may be spread across Ethereum, Polygon, and other supported networks. Prefer this over chain-specific NFT APIs when the target chain is unknown or when comprehensive coverage matters.

## Known failure modes

- Invalid or malformed wallet address returns a 400 error
- Unsupported chain identifier results in partial or empty results
- Payment not included or insufficient USDC triggers a 402 Payment Required response
- Rate limiting or quota exceeded returns a 429 error
- Wallet with no NFT holdings returns an empty result set
- Network timeout on heavily loaded chains may cause partial responses

## How this service works

Portfolio API — multi-chain NFT holdings for one or more wallet addresses (not chain-specific).

## Output

A structured list of all NFTs owned by the specified wallet address(es), including token IDs, contract addresses, collection names, NFT metadata, and which blockchain each NFT lives on — aggregated across all supported chains in a single response.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/alchemy-0a0be618/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.alchemy.com](https://www.zero.xyz/host/x402.alchemy.com/llms.txt)