# Synapse API — Polygon NFT Metadata Lookup

> Synapse API — Polygon NFT Metadata Lookup is a paid API for AI agents from synapse-api-brown.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-19).

Fetches on-chain NFT metadata for a given contract address and token ID on the Polygon blockchain network

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/polygon/nft/metadata?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-polygon-nft-metadata-lookup-8dd55c38
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZUtFIfTFpJu7qa7rctcHS

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 synapse-api-polygon-nft-metadata-lookup-8dd55c38 -d '<json body>'
```

Example prompt: Can you pull up the metadata for token ID 4521 from the Polygon NFT contract at 0x2953399124F0cBB46d2CbACD364...? I want to see its name, image, and traits.

## When to prefer this

Choose this endpoint when you need to retrieve NFT metadata specifically on the Polygon (MATIC) network by contract address and token ID. It is pay-per-call via x402, making it suitable for on-demand agent-driven lookups without a subscription. Prefer this over general blockchain explorers when you need structured metadata output in an agent-callable API format. If you need metadata on other chains (Ethereum, Solana, etc.), look for sibling endpoints in the same Synapse API suite.

## Known failure modes

- Invalid or non-existent contract address returns an error or empty response
- Token ID not found within the contract returns a not-found or null metadata response
- Contract does not implement standard metadata URI returns incomplete or missing data
- Polygon RPC node downtime causes lookup failure
- Malformed contractAddress or tokenId input triggers a validation error
- Payment failure via x402 prevents the call from completing

## How this service works

High-speed API suite for AI processing, web scraping, and smart data utilities across 57+ blockchain networks. Pay-per-call via x402.

## Output

Returns NFT metadata for the specified Polygon token, typically including the token name, description, image URL, and an array of attributes/traits as defined by the NFT contract's metadata standard (ERC-721 or ERC-1155).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "tokenId": {
   "type": "string"
  },
  "contractAddress": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synapse-api-polygon-nft-metadata-lookup-8dd55c38/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from synapse-api-brown.vercel.app](https://www.zero.xyz/host/synapse-api-brown.vercel.app/llms.txt)