# Token Allowance Lookup

> Token Allowance Lookup is a paid API for AI agents from stablecrypto.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Returns the ERC-20 token allowance (approved spending amount) for a given owner/spender pair on a specified network

## Facts

- Endpoint: POST https://stablecrypto.dev/api/alchemy/token/token-allowance
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/token-allowance-lookup-0a364bc2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3OXbXVK59De5I_OrGxPbg

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 token-allowance-lookup-0a364bc2 -d '<json body>'
```

Example prompt: On Ethereum mainnet, what's the USDC allowance that my wallet 0xAbC...123 has approved for the Uniswap v3 router 0xE592...aB5 — look it up using the USDC contract 0xA0b8...eB48?

## When to prefer this

Use this endpoint when you need to check the current ERC-20 token spending allowance between a specific owner and spender on a supported EVM network via Alchemy. Prefer this over raw RPC calls when you want a simple, cost-effective REST interface without constructing raw eth_call payloads. Ideal for DeFi agents auditing approvals, verifying pre-conditions before swaps, or monitoring unlimited approvals.

## Known failure modes

- Invalid or malformed Ethereum address for owner, spender, or contract returns an error
- Unsupported or misspelled network slug (e.g. 'ethereum' instead of 'eth-mainnet') returns an error
- Non-ERC-20 contract address returns an error or zero allowance
- Network connectivity or Alchemy node issues may cause timeout or 5xx errors
- Zero allowance returned when no approval has been set — not an error, but may be misread as failure

## How this service works

Pay-per-request access to CoinGecko, DefiLlama, Alchemy, and Etherscan APIs. No auth, no subscriptions.

## Output

A string representing the token allowance amount in the token's smallest unit (e.g. wei for ETH-based tokens), indicating how many tokens the spender is approved to transfer on behalf of the owner.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "owner": {
   "type": "string",
   "description": "Owner address"
  },
  "network": {
   "type": "string",
   "description": "Alchemy network slug, e.g. eth-mainnet, base-mainnet"
  },
  "spender": {
   "type": "string",
   "description": "Spender address"
  },
  "contract": {
   "type": "string",
   "description": "Token contract address"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/token-allowance-lookup-0a364bc2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from stablecrypto.dev](https://www.zero.xyz/host/stablecrypto.dev/llms.txt)