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WSS
Messages
subscribe
type:object
unsubscribe
type:object
subscribe_response
type:object
unsubscribe_response
type:object
update
type:object

​
Overview

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Subscription Parameters

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chain_id
number
required
Target EVM network. See the Chain enumeration for supported values.

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Message Fields

Each message in the stream follows the standard block schema:
​
block_number
number
Sequential block height.
​
block_hash
string
Keccak-256 hash of the block header (32 bytes, hex string, no 0x prefix).
​
parent_block_hash
string
Keccak-256 hash of the parent block.
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miner
string
Fee recipient / coinbase address.
​
timestamp_utc
string
Timestamp when the block was mined.
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_tracing_id
string
Tracing identifier for the canonical block record.
​
is_reorg
boolean
If true, this message is a reorg correction and should be treated as an overwrite of previously emitted state at the same natural key (for blocks: block_number).

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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": "0101", "chain_id": 1, "params": {}}'

​
Response Example

{
  "chain_id": 1,
  "dataset_id": "0101",
  "is_reorg": false,
  "data": {
    "block_number": 12345678,
    "block_hash": "7b5c0972efb6a0b5be4a4d4a0de5d1abd922478a53f32b2c717a800c862ba9e0",
    "parent_block_hash": "f78e26c5959a94d6a62ed3837f5dcecf0d3761bf0a502e12a08fd7bc44c8568d",
    "receipt_root": "b4d8cfe4b87590afe7ed95fbf7798142e8fb1ce86307ff0eb6580b8bc23de92f",
    "miner": "0000000000000000000000000000000000000000",
    "gas_limit": 30000000,
    "extra_data": "636c61737369635f657468657265756d",
    "size": 124836,
    "timestamp_utc": "2025-11-11T18:42:15.123Z",
    "_tracing_id": "010200000000000000000000000000000000",
    "_computed_receipt_root": "b4d8cfe4b87590afe7ed95fbf7798142e8fb1ce86307ff0eb6580b8bc23de92f",
    "_computed_receipt_timestamp_utc": "2025-11-11T18:43:00.000Z",
    "_created_at": "2025-11-11T18:42:15.123Z",
    "_updated_at": "2025-11-11T18:42:15.123Z"
  }
}
Last modified on April 6, 2026