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Base ERC-20 Approval Exposure Analyzer
x402
Base ERC-20 Approval Exposure Analyzer is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.015/call, status unknown (last checked 2026-09-15).
Analyzes caller-supplied transaction or approval data to identify ERC-20 token approval exposures (owner, spender, token, delta, unlimited flag) on the Base network.
Price / call$0.015
Success—
StatusUnknown
How this service works
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Output
Returns a structured JSON analysis containing: a list of approval records (owner, spender, token address, allowance before/after, delta, unlimited flag), a spender exposure summary (total allowance per spender, unlimited flag), and Base network context (chain IDs, fee model, protocol family). Also includes a warning that live on-chain allowances are not queried or revoked.
Example use cases
Detect unlimited token approvals in DeFi
“I just interacted with a DeFi protocol on Base — can you check this transaction data and flag any spenders that received unlimited ERC-20 token approvals?”
Audit spender exposure before signing
“Before I broadcast this Base transaction, analyze the approval data and tell me exactly which addresses will be able to spend my tokens and for how much.”
Security review of historical approval events
“Here's some approval event data from a Base contract interaction — can you extract the owner, spender, token, and allowance delta for each approval so I can review my exposure?”
Technical details
Endpoint
POSThttps://signalharness.ai/api/agent/services/base_erc20_approval_exposure/invokeWhen to prefer
Use this endpoint when you have raw ERC-20 approval transaction data or event logs from the Base network and need to extract structured approval exposure details (who approved whom, for how much, whether unlimited). Ideal for security audits, pre-signing checks, and DeFi risk summaries. Prefer this over on-chain RPC calls when you already have the data and need fast, structured parsing without live blockchain queries.
Side effects
- Malformed or non-JSON request_json input returns a parse error
- Missing required approval fields in the input data may produce incomplete analysis
- Data describing non-Base networks may be analyzed but flagged or produce unexpected network context
- Overly large input (exceeding 65536 character limit) will be rejected
- The service does not verify on-chain state — analysis is limited to caller-supplied data only
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| request_json | string |
Output
Schema · Response
{
"type": "json",
"example": {
"replay": false,
"result": {
"warnings": [
"Does not query or revoke current allowances."
],
"service_id": "base_erc20_approval_exposure",
"analysis_json": "{\"approvals\":[{\"after\":\"100\",\"before\":\"0\",\"delta\":\"100\",\"owner\":\"0x0000000000000000000000000000000000000001\",\"spender\":\"0x0000000000000000000000000000000000000002\",\"token\":\"0x0000000000000000000000000000000000000001\",\"unlimited\":false}],\"network_context\":{\"accepted_chain_ids\":[\"8453\",\"84532\"],\"deposit_transaction_type\":\"0x7e\",\"fee_model\":\"L2 execution plus caller-supplied L1 data/operator components\",\"protocol_family\":\"OP Stack\"},\"spender_exposure\":[{\"spender\":\"0x0000000000000000000000000000000000000002\",\"total_after\":\"100\",\"unlimited\":false}]}",
"evidence_scope": "caller_supplied_data",
"analyzed_network": "base"
},
"status": "succeeded",
"receipt": {
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"usage": [],
"status": "succeeded",
"network": "eip155:8453",
"artifacts": [],
"endedAtMs": 0,
"latencyMs": 0,
"paymentId": "example-payment",
"receiptId": "example-receipt",
"requestId": "example-request",
"serviceId": "base_erc20_approval_exposure",
"executionId": "example-execution",
"startedAtMs": 0,
"amountAtomic": "15000",
"resultSha256": "b1af0703709aad699dd6c556c7f91457ae948eae262e3f400e491f395b7ee4c3",
"serviceVersion": "1.0.0",
"settlementReference": "0x0000000000000000000000000000000000000000000000000000000000000000"
},
"artifacts": [],
"requestId": "example-request",
"executionId": "example-execution"
}
}Tags
x402
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