Overview
Subscription Parameters
Target EVM network. See the Chain enumeration for supported values. Filter by emitting contract address (hex string, 20 bytes, no 0x prefix).
Filter by the primary event topic (e.g., Transfer, Swap signature hashes).
Message Fields
Payload mirrors blockdb_evm.b0103_logs_v1 (binary fields as hex strings without 0x in JSON).
Address of the emitting contract.
Primary topic hash identifying the event (32 bytes). null for anonymous events.
Subsequent event topics (indexed parameters).
Raw event data payload (hex string (no 0x prefix)).
Block height containing the log.
Tracing identifier for lineage correlation.
Record creation time (ISO-8601).
Record last update time (ISO-8601).
Subscription Example
# Use wscat to connect and subscribe
wscat -c wss://api.blockdb.io/v1/evm/ \
-H "Authorization: Bearer $BLOCKDB_API_KEY" \
-x '{"action": "subscribe", "dataset_id": "0103", "chain_id": 1, "params": {"topic_zeros": ["ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"]}}'
Response Example
{
"chain_id": 1,
"dataset_id": "0103",
"is_reorg": false,
"data": {
"block_number": 12345678,
"block_time": "2025-11-11T18:42:15.123Z",
"tx_index": 4,
"log_index": 0,
"contract_address": "0000000000000000000000000000000000000000",
"topic_zero": "ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
"data_topics": [
"0000000000000000000000000000000000000000000000000000000000000000",
"0000000000000000000000000000000000000000000000000000000000000001"
],
"data": "00000000000000000000000000000000000000000000000000000000000003e8",
"_tracing_id": "0103000000000000000000000000000000000000",
"_created_at": "2025-11-11T18:42:15.123Z",
"_updated_at": "2025-11-11T18:42:15.123Z"
}
}
