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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.
​
contract_address
string
Optional filter: one contract address (20-byte hex, no 0x prefix).

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Message Fields

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contract_id
string
Unique contract incarnation ID (26 bytes hex).
​
contract_address
string
ERC-1155 contract address (20-byte hex).
​
block_number
number
Block where the contract was recognized.
​
block_time
string
Block time (ISO-8601).
​
tx_index
number
Transaction index.
​
name
string | null
Contract-level name when present.
​
symbol
string | null
Contract-level symbol when present.
​
decimals
number | null
Decimals when exposed by the contract.
​
uri
string | null
URI from uri(uint256) (optional ERC1155Metadata_URI).
​
supports_metadata_uri
boolean | null
Whether the contract supports the ERC1155Metadata_URI extension; null when detection was via fallback.
​
_tracing_id
string
Lineage id (hex).
​
_parent_tracing_ids
string[]
Parent lineage ids (hex).
​
_created_at
string
Record creation time (ISO-8601).
​
_updated_at
string
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": "0203", "chain_id": 1, "params": {}}'

​
Response Example

{
  "chain_id": 1,
  "dataset_id": "0203",
  "is_reorg": false,
  "data": {
    "contract_id": "0000000000000000000000000000000000000000000000000000",
    "contract_address": "495f947276749ce646f68ac8c248420045cb7b5e",
    "block_number": 11579209,
    "block_time": "2021-10-15T12:00:00Z",
    "tx_index": 42,
    "name": "OpenSea Shared Storefront",
    "symbol": "OPENSTORE",
    "decimals": null,
    "uri": "https://api.opensea.io/api/v1/metadata/{id}",
    "supports_metadata_uri": true,
    "_tracing_id": "0203000000000000000000000000000000000001",
    "_parent_tracing_ids": [
      "0103000000000000000000000000000000000001"
    ],
    "_created_at": "2025-11-11T18:42:15.123Z",
    "_updated_at": "2025-11-11T18:42:15.123Z"
  }
}
Last modified on April 6, 2026