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SignalHarness Base Event Sequence Analyzer
x402
SignalHarness Base Event Sequence Analyzer is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.015/call, status unknown (last checked 2026-09-14).
Analyzes and orders a sequence of Base blockchain events, resolving ambiguities in event ordering and returning structured analysis with chain context.
Price / call$0.015
Success—
StatusUnknown
How this service works
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Output
Returns a JSON analysis including whether event ordering is ambiguous, the count of events, an ordered list of events with their source index, address, block number, chain ID, log index, and transaction index, plus network context for Base (accepted chain IDs, deposit transaction type, fee model, and OP Stack protocol family). Also returns evidence scope and analyzed network identifier.
Example use cases
Verify DeFi transaction event order
“I have a series of events from a Base mainnet DeFi transaction — transfer and swap logs with their block numbers and log indexes. Can you analyze them and tell me if their ordering is unambiguous and what the canonical sequence is?”
Debug smart contract log sequencing
“I'm debugging a smart contract on Base and I have about 5 event logs with different transaction indexes. Can you run them through the Base event sequence analyzer and tell me if there's any ordering ambiguity?”
Audit cross-contract event timeline
“I need to audit the event timeline for a series of interactions across two Base contracts — here are the raw events with block numbers and log indexes. Can you analyze the sequence and flag any ordering issues?”
Technical details
Endpoint
POSThttps://signalharness.ai/api/agent/services/base_event_sequence_analyze/invokeWhen to prefer
Use this endpoint when you have a set of raw Base blockchain event logs and need to determine their canonical ordering or detect ordering ambiguity. It is purpose-built for Base (chain ID 8453) and Base Sepolia (84532) with OP Stack-aware context, making it more appropriate than generic EVM log parsers when working specifically on Base. Ideal for agents auditing DeFi transactions, debugging smart contract interactions, or building reliable event-driven pipelines on Base.
Side effects
- Missing or malformed request_json causes validation error
- Events without required block/transaction/log indexes may produce unreliable ordering
- Supplying events from unsupported chain IDs (not 8453 or 84532) may return an error or unrecognized network
- Empty event list may return empty analysis
- Extremely large event arrays may exceed maxLength constraint on request_json
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| request_json | string |
Output
Schema · Response
{
"type": "json",
"example": {
"replay": false,
"result": {
"warnings": [
"Ordering relies on supplied block/transaction/log indexes."
],
"service_id": "base_event_sequence_analyze",
"analysis_json": "{\"ambiguous_order\":false,\"count\":1,\"events\":[{\"_source_index\":0,\"address\":\"0x0000000000000000000000000000000000000001\",\"block_number\":1,\"chain\":\"8453\",\"log_index\":0,\"transaction_index\":0}],\"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\"}}",
"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_event_sequence_analyze",
"executionId": "example-execution",
"startedAtMs": 0,
"amountAtomic": "15000",
"resultSha256": "63250bafa752cc7ac2e6c3887baf92a5b318588976e94347d0fc1baba966c87f",
"serviceVersion": "1.0.0",
"settlementReference": "0x0000000000000000000000000000000000000000000000000000000000000000"
},
"artifacts": [],
"requestId": "example-request",
"executionId": "example-execution"
}
}Tags
x402
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