{"uid":"cap_aFnp3U1unVFEdyK4Gdr-z","slug":"defi-shield-hazel-vercel-app-4105a385","name":"EVM Event Log Decoder","description":"Decodes on-chain event data into structured fields. Submit raw event logs to receive human-readable decoded output.","url":"https://defi-shield-hazel.vercel.app/api/data/event-decode","method":"POST","headers":{},"bodySchema":null,"responseSchema":null,"example":{"request":{"log_data":"0x0000000000000000000000000000000000000000000000000000000000001000","log_topics":["0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef","0x0000000000000000000000001111111111111111111111111111111111111111","0x0000000000000000000000002222222222222222222222222222222222222222"]},"response":{"success":true,"raw_data":"0x0000000000000000000000000000000000000000000000000000000000001000","event_name":"Transfer","raw_topics":["0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef","0x0000000000000000000000001111111111111111111111111111111111111111","0x0000000000000000000000002222222222222222222222222222222222222222"],"topic_count":3,"decoded_args":{"to":"0x2222222222222222222222222222222222222222","from":"0x1111111111111111111111111111111111111111","value":"4096"},"match_source":"known_events","event_signature":"Transfer(address,address,uint256)","response_time_ms":1,"event_signature_hash":"0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"}},"exampleRequest":{"log_data":"0x0000000000000000000000000000000000000000000000000000000000001000","log_topics":["0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef","0x0000000000000000000000001111111111111111111111111111111111111111","0x0000000000000000000000002222222222222222222222222222222222222222"]},"tags":["x402"],"displayCostAmount":"0.1","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.1/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_ZPlrDczE-AZmgGJmFSCe9","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.1","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Decodes raw EVM event log data (topics and data fields) into human-readable event names and typed parameters","exampleAgentPrompt":"Can you decode this raw EVM event log for me — the log data is 0x0000000000000000000000000000000000000000000000000000000000001000 and the topics are [0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000001111111111111111111111111111111111111111, 0x0000000000000000000000002222222222222222222222222222222222222222] — I want to know the event name and the decoded parameter values.","exampleUseCases":[{"title":"Monitor DeFi token transfers in real-time","prompt":"I'm watching a blockchain for token movements. I just got a raw event log with data 0x0000000000000000000000000000000000000000000000000000000000000064 and topics [0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x000000000000000000000000aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa, 0x000000000000000000000000bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb]. Can you decode this and tell me what event it is, who sent tokens to whom, and how many?"},{"title":"Analyze Uniswap swap events from transaction logs","prompt":"I'm tracking Uniswap trades on Base chain. I have a raw log from a swap transaction with data 0x00000000000000000000000000000000000000000000000000000000000003e8 and topics [0xc42079f94a6350d7e6235f29174924f928cc2ac818eb64fed8004e115fbcca67, 0x0000000000000000000000003333333333333333333333333333333333333333, 0x0000000000000000000000004444444444444444444444444444444444444444]. Decode this for me so I can understand which tokens were swapped and the amounts involved."},{"title":"Parse unknown smart contract event emissions","prompt":"I just intercepted a transaction log from a smart contract I'm not familiar with. The raw data is 0x0000000000000000000000000000000000000000000000008ac7230489e80000 and the topics are [0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925, 0x0000000000000000000000005555555555555555555555555555555555555555, 0x0000000000000000000000006666666666666666666666666666666666666666]. What event was emitted here and what are the parameter values?"}],"resultDescription":"Returns the event name (e.g. 'Transfer'), the full event signature (e.g. 'Transfer(address,address,uint256)'), the event signature hash, decoded argument key-value pairs (e.g. from/to/value), raw topics, topic count, match source (e.g. 'known_events'), raw data, and response time in milliseconds.","failureModes":["Unknown event signature hash — returns no match if the topic0 hash is not in the known events registry","Malformed hex data — invalid or truncated log_data or log_topics cause parsing errors","Missing required fields — omitting log_topics or log_data results in a 400-style error","Ambiguous ABI — logs from unverified contracts with non-standard events may not decode correctly","Payment failure — x402 payment of 0.1 USDC not provided or rejected"],"whenToPreferThis":"Use this endpoint when you have raw EVM transaction receipt log data (hex-encoded data and topics arrays) and need to convert them into human-readable event names and typed parameter values. Ideal for DeFi analytics pipelines, transaction monitoring agents, or any workflow that processes on-chain events from Ethereum, Base, or other EVM-compatible chains and needs structured, interpretable output without running a full node or maintaining a local ABI registry.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T12:51:33.622Z","isFirstParty":false}