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WSS
wss://stream.blockdb.io/v1/evm/
Messages
subscribe
type:object
unsubscribe
type:object
subscribe_response
type:object
unsubscribe_response
type:object
update
type:object

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Description

The Spot OHLC stream delivers real-time open-high-low-close (OHLC) candle updates for ERC-20 token pairs. Candles are updated as new trades and quote changes occur on-chain.

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Subscription Parameters

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chain_id
number
required
Target EVM network.
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base_token_address
string
required
ERC-20 contract address for the base asset.
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quote_token_address
string
required
ERC-20 contract address for the quote asset.
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aggregation_interval
string
default:"1m"
Candle width (e.g., 1m, 5m, 1h).

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Message Fields

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open
string
Opening price for the current bucket.
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high
string
Highest price within the bucket so far.
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low
string
Lowest price within the bucket so far.
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close
string
Current closing (latest) price for the bucket.
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volume_base
string
Aggregated executed volume in base units.
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bucket
string
Bucket anchor timestamp.
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_tracing_id
string
Row-level lineage hash for correlation.

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Subscription Example

# Use wscat to connect and subscribe
wscat -c wss://stream.blockdb.io/v1/evm/ \
  -H "Authorization: Bearer $BLOCKDB_API_KEY" \
  -x '{"action": "subscribe", "dataset_id": "0403", "chain_id": 1, "params": {"base_token_address": "c02aaa39b223fe8d0a0e5c4f27ead9083c756cc2", "quote_token_address": "a0b86991c6218b36c1d19d4a2e9eb0ce3606eb48", "aggregation_interval": "1m"}}'

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Response Example

{
  "chain_id": 1,
  "dataset_id": "0403",
  "is_reorg": false,
  "data": {
    "base_token_address": "c02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
    "quote_token_address": "a0b86991c6218b36c1d19d4a2e9eb0ce3606eb48",
    "open": "3010.112233445566778899",
    "high": "3033.998877665544332211",
    "low": "3008.001122334455667788",
    "close": "3025.219821481234567890",
    "volume_base": "420.000000000000000000",
    "bucket": "2025-11-11T00:00:00Z",
    "_tracing_id": "0403000000000000000000000000000000000000",
    "_created_at": "2025-11-11T01:00:05.000Z"
  }
}