# ERC-20 Allowance Lookup (Polygon) — Saylor Innovations

> ERC-20 Allowance Lookup (Polygon) — Saylor Innovations is a paid API for AI agents from saylorinnovations.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-03).

Returns the current ERC-20 token spending allowance granted by a token owner to a spender on the Polygon network

## Facts

- Endpoint: GET https://saylorinnovations.com/api/evm/polygon/allowance/:address/:address2/:address3?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-03
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/erc-20-allowance-lookup-polygon-saylor-innovations-60f39de4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_y_vVTdJl7fQwgeMexCDPx

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 erc-20-allowance-lookup-polygon-saylor-innovations-60f39de4
```

Example prompt: What is the current ERC-20 allowance that wallet 0xOwnerAddress has granted to spender 0xSpenderAddress for the token contract 0xTokenAddress on Polygon?

## When to prefer this

Use this endpoint when you specifically need to check ERC-20 token allowances on the Polygon (MATIC) network. Prefer this over generic blockchain explorers when you need programmatic, low-latency allowance data suitable for automated DeFi workflows, security audits, or agent-driven on-chain decision making. Choose this over the BSC or Base sibling endpoints when the token and approval are on Polygon.

## Known failure modes

- Invalid or malformed wallet/contract address returns an error
- Non-existent or non-ERC-20 contract address may return zero or an error
- Polygon RPC node unavailability causes timeout or service error
- Zero allowance returned when no approval exists (not necessarily an error)
- Rate limiting if too many requests are made in quick succession

## How this service works

ERC-20 Allowance (polygon). Polygon ERC-20 allowance: how much a spender may move from an owner, human-readable, with an unlimited-approval flag.

## Output

Returns the numeric allowance (token amount) that the owner address has approved the spender address to transfer on their behalf for the specified ERC-20 token contract on the Polygon network. The value is typically in the token's smallest unit (e.g. wei-equivalent).

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/erc-20-allowance-lookup-polygon-saylor-innovations-60f39de4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from saylorinnovations.com](https://www.zero.xyz/host/saylorinnovations.com/llms.txt)