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Apiosk Gateway – On-Chain Reserve Attestation (Base)
x402
Apiosk Gateway – On-Chain Reserve Attestation (Base) is a paid API for AI agents from gateway.apiosk.com, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-16).
Reads the ERC-20 balanceOf for a given token/holder pair on Base at the current block and returns the balance with a JWS-HS256 signed receipt that includes the exact eth_call parameters for independent verification.
Price / call$0.03
Success—
StatusUnknown
How this service works
Read balanceOf for a token/holder pair on Base at the current block and return the balance with a signed JWS-HS256 receipt. The envelope carries the exact eth_call (contract, calldata, block) so anyone can re-run it against any Base node.
Output
A JSON response containing the current ERC-20 token balance for the specified holder, wrapped in a JWS-HS256 signed envelope. The envelope includes the exact eth_call parameters (contract address, calldata, block number) so any third party can independently re-run the query against any Base node to confirm the result.
Example use cases
Proof-of-reserves for a stablecoin issuer
“I need a signed attestation of the USDC balance held by our treasury wallet 0xDEF...789 on Base right now — something an auditor can independently verify against a Base node.”
DeFi collateral verification before a loan
“Before I approve this loan, can you pull a signed on-chain balance receipt for the collateral token at contract 0xAAA...111 held by wallet 0xBBB...222 on Base so I can confirm the position is fully backed?”
Compliance snapshot for a regulated wallet
“I need a tamper-evident record of exactly how many tokens wallet 0x999...FFF holds on Base for our quarterly compliance filing — please get a JWS-signed balance attestation I can archive.”
Technical details
Endpoint
POSThttps://gateway.apiosk.com/attestations/onchain-reserveWhen to prefer
Choose this endpoint when you need a cryptographically signed, independently verifiable proof of an ERC-20 token balance on Base — not just a raw balance read. It is ideal for audit trails, reserve attestations, compliance snapshots, or any scenario where a third party must be able to verify the result without trusting the caller. It is not suitable if you only need an unsigned balance for internal logic, or if you are querying chains other than Base.
Side effects
- Invalid or non-ERC-20 contract address returns an error or zero balance
- Wallet address not checksummed or malformed causes a 400-level error
- Temporary Base RPC unavailability may cause a timeout or 503
- Payment not completed via x402 results in HTTP 402 response
- Block reorg between call and receipt delivery could cause minor inconsistency
Tags
x402
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