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SALT19 Base Token Allowance Lookup
x402
SALT19 Base Token Allowance Lookup is a paid API for AI agents from api.salt19.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).
Returns the current ERC-20 token allowance granted by an owner address to a spender address on the Base network
Price / call$0.01
Success—
StatusUnknown
How this service works
SALT19 is an independent applied AI systems lab behind EvoMind governed cognition, the MCP-native Agent Utility Grid, the ARCS research community, AeroClear UAS flight intelligence, and practical software for real-world work.
Output
Returns a JSON object containing the network identifier (eip155:8453 for Base), the block number at which the allowance was read, and the allowance amount in atomic (smallest) units as a string. A value of '0' means no approval has been granted.
Example use cases
Pre-swap allowance verification
“Before I execute this swap, can you check whether my wallet 0xAbC1234567890AbC1234567890AbC1234567890Ab has already approved the Uniswap router 0x2626664c2603336E57B271c5C0b26F421741e481 to spend my USDC token at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base, and tell me what the current allowance is?”
DeFi protocol approval audit
“I want to audit how much of my token at 0xd9aAEc86B65D86f6A7B5B1b0c42FFA531710b6CA I've approved the Aave lending pool at 0x18CD499e3d7ed42fEBFa1C6a547a4D5516D4760e to spend — can you pull the current allowance from Base for owner 0xAbC1234567890AbC1234567890AbC1234567890Ab?”
Agent spending limit check
“My AI agent wallet is 0xDeF0987654321DeF0987654321DeF0987654321De and the treasury contract is 0xAbC1234567890AbC1234567890AbC1234567890Ab — check what allowance the treasury has granted the agent for the token 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base so I know if it can execute the next payment.”
Technical details
Endpoint
POSThttps://api.salt19.com/v1/base-token-allowanceWhen to prefer
Choose this endpoint when you need on-chain ERC-20 allowance data specifically on the Base network (eip155:8453) and want a simple pay-per-call REST interface without managing your own RPC infrastructure. Particularly useful for AI agents in the SALT19/EvoMind ecosystem that need to verify approval state before executing DeFi actions, or for pre-flight checks before token transfers.
Side effects
- Invalid Ethereum address format (must be 0x-prefixed 40 hex chars) returns a validation error
- Token address not found or not an ERC-20 contract may return zero or an error
- Network congestion or RPC node unavailability may cause timeouts
- Payment of $0.01 USDC not received results in 402 Payment Required response
- Malformed JSON body returns a 400 Bad Request
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| owner | string | |
| spender | string | |
| token_address | string |
Output
Schema · Response
{
"type": "json",
"example": {
"network": "eip155:8453",
"block_number": 12345678,
"allowance_atomic": "0"
}
}Tags
x402
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