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SignalHarness ABI Event Topics Decoder
x402
SignalHarness ABI Event Topics Decoder is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-16).
Decodes ABI-encoded Ethereum event topics from smart contract logs into human-readable structured data
Price / call$0.01
Success—
StatusUnknown
How this service works
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Output
Returns a JSON object containing decoded event topics as human-readable data, any warnings about the input data, the service ID, and an evidence scope indicator. Also includes a full execution receipt with payment details, latency, a SHA-256 result hash, and settlement reference for auditability.
Example use cases
Parse ERC20 Transfer Event Logs
“I have raw log topics from an Ethereum transaction receipt that look like hex strings — can you decode these ABI event topics so I can see the sender, receiver, and token amount from the Transfer event?”
Debug Smart Contract Event Emission
“My smart contract emitted an event but I only have the raw topics array from the tx log. Decode these ABI event topics for me so I can verify the correct arguments were emitted during the contract call.”
Extract NFT Mint Event Parameters
“I'm indexing NFT mint events and I have a raw topics array from a contract log. Can you decode these ABI-encoded event topics to extract the token ID and recipient address from the Transfer event?”
Technical details
Endpoint
POSThttps://signalharness.ai/api/agent/services/abi_event_topics/invokeWhen to prefer
Choose this endpoint when you need to decode raw ABI-encoded Ethereum event topics from smart contract transaction logs into structured, human-readable data. It is purpose-built for EVM log decoding, operates per-call at $0.01 USDC via x402, and returns an auditable receipt with a result hash — making it suitable for agent pipelines that require verifiable blockchain data extraction.
Side effects
- Malformed or truncated ABI topic string returns a warning or failed status
- Input that is not valid ABI-encoded data may produce incorrect or empty decoded output
- Exceeding the 65536-character input limit causes a validation error
- Unsupported or unrecognized ABI event signatures may result in partial decoding with warnings
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| abi_event_topics_request | string |
Output
Schema · Response
{
"type": "json",
"example": {
"replay": false,
"result": {
"warnings": [
"Constructed topics do not query any chain."
],
"service_id": "abi_event_topics",
"event_topics": "{\"signature\":\"Changed(address,uint256)\",\"topics\":[\"0xb52dda022b6c1a1f40905a85f257f689aa5d69d850e49cf939d688fbe5af5946\",\"0x0000000000000000000000000000000000000000000000000000000000000001\"]}",
"evidence_scope": "caller_supplied_data"
},
"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": "abi_event_topics",
"executionId": "example-execution",
"startedAtMs": 0,
"amountAtomic": "10000",
"resultSha256": "6858fbc2bffcb1165931364d11fdbcfc05e8571ab284c6513dcb18cce06b38f3",
"serviceVersion": "1.0.0",
"settlementReference": "0x0000000000000000000000000000000000000000000000000000000000000000"
},
"artifacts": [],
"requestId": "example-request",
"executionId": "example-execution"
}
}Tags
x402
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