Messages
No examples found{
"action": "<string>",
"chain_id": 123,
"dataset_id": "<string>"
}{
"action": "<string>",
"chain_id": 123,
"dataset_id": "<string>",
"status": "<string>",
"error": {
"code": "<string>",
"message": "<string>",
"severity": "<string>",
"retryable": true
}
}{
"action": "<string>",
"chain_id": 123,
"dataset_id": "<string>",
"status": "<string>",
"error": {
"code": "<string>",
"message": "<string>",
"severity": "<string>",
"retryable": true
}
}{
"chain_id": 123,
"dataset_id": "<string>",
"is_reorg": true,
"data": {
"block_number": 123,
"tx_index": 123,
"from_address": "<string>",
"to_address": "<string>",
"token_address": "<string>",
"transfer_type": "<string>",
"amount_raw": "<string>",
"_tracing_id": "<string>"
}
}Transfers
Token Transfers
Subscribe to real-time token transfer events.
WSS
/
Overview
- Dataset ID:
0304 - Token Transfers - Description: Token transfer events (native ETH, ERC-20, ERC-721, ERC-1155) produced by TokenTransfersEngine from transactions, internal transactions, and transfer logs.
- Sample: Hugging Face Sample
Subscription Parameters
Optional filter: sender addresses (hex, no
0x).Optional filter: recipient addresses (hex, no
0x).Optional filter: token contract addresses (hex, no
0x); omit for native transfers where applicable.Optional filter: transfer kinds (e.g.
native, erc20, erc721, erc1155).Message Fields
Block containing the transfer.
Block time (ISO-8601).
Transaction index within the block.
Log index when sourced from a log; null when not applicable.
Trace address for internal tx transfers (e.g.
"0", "0.1"); null for other types.Sender address (hex).
Recipient address (hex).
Token contract; null for native ETH transfers.
Raw amount (integer string in token/native units).
Decimal-adjusted amount; null if decimals unknown or NFT.
NFT / ERC-1155 id when applicable.
Transfer mechanism as integer enum (see Transfer Type).
Row lineage id (hex).
Parent lineage ids (hex).
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": "0304", "chain_id": 1, "params": {}}'
#include <libwebsockets.h>
#include <string.h>
#include <stdio.h>
static int callback_blockdb(struct lws *wsi, enum lws_callback_reasons reason,
void *user, void *in, size_t len) {
switch (reason) {
case LWS_CALLBACK_CLIENT_ESTABLISHED:
lws_callback_on_writable(wsi);
break;
case LWS_CALLBACK_CLIENT_RECEIVE:
printf("Received: %s\n", (char *)in);
break;
case LWS_CALLBACK_CLIENT_WRITEABLE: {
unsigned char buf[LWS_PRE + 1024];
unsigned char *p = &buf[LWS_PRE];
size_t n = sprintf((char *)p, "{\"action\": \"subscribe\", \"dataset_id\": \"0304\", \"chain_id\": 1, \"params\": {}}");
lws_write(wsi, p, n, LWS_WRITE_TEXT);
break;
}
}
return 0;
}
using System;
using System.Net.WebSockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
class Program {
static async Task Main() {
using var ws = new ClientWebSocket();
ws.Options.SetRequestHeader("Authorization", $"Bearer {Environment.GetEnvironmentVariable("BLOCKDB_API_KEY")}");
await ws.ConnectAsync(new Uri("wss://api.blockdb.io/v1/evm/"), CancellationToken.None);
var subMsg = "{\"action\": \"subscribe\", \"dataset_id\": \"0304\", \"chain_id\": 1, \"params\": {}}";
await ws.SendAsync(new ArraySegment<byte>(Encoding.UTF8.GetBytes(subMsg)), WebSocketMessageType.Text, true, CancellationToken.None);
var buffer = new byte[1024 * 4];
while (ws.State == WebSocketState.Open) {
var result = await ws.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);
Console.WriteLine(Encoding.UTF8.GetString(buffer, 0, result.Count));
}
}
}
import websocket
import json
import os
def on_message(ws, message):
print(f"Received: {message}")
def on_open(ws):
msg = {
"action": "subscribe",
"dataset_id": "0304",
"chain_id": 1,
"params": {}
}
ws.send(json.dumps(msg))
ws = websocket.WebSocketApp(
"wss://api.blockdb.io/v1/evm/",
header={"Authorization": f"Bearer {os.getenv('BLOCKDB_API_KEY')}"},
on_message=on_message,
on_open=on_open
)
ws.run_forever()
const WebSocket = require('ws');
const ws = new WebSocket('wss://api.blockdb.io/v1/evm/', {
headers: { 'Authorization': `Bearer ${process.env.BLOCKDB_API_KEY}` }
});
ws.on('open', () => {
ws.send(JSON.stringify({
action: 'subscribe',
dataset_id: '0304',
chain_id: 1,
params: {}
}));
});
ws.on('message', (data) => {
console.log('Received:', JSON.parse(data));
});
package main
import (
"fmt"
"log"
"net/http"
"os"
"github.com/gorilla/websocket"
)
func main() {
header := http.Header{"Authorization": []string{"Bearer " + os.Getenv("BLOCKDB_API_KEY")}}
c, _, err := websocket.DefaultDialer.Dial("wss://api.blockdb.io/v1/evm/", header)
if err != nil {
log.Fatal("dial:", err)
}
defer c.Close()
sub := `{"action": "subscribe", "dataset_id": "0304", "chain_id": 1, "params": {}}`
err = c.WriteMessage(websocket.TextMessage, []byte(sub))
if err != nil {
log.Fatal("write:", err)
}
for {
_, message, err := c.ReadMessage()
if err != nil {
log.Fatal("read:", err)
}
fmt.Printf("Received: %s\n", message)
}
}
Response Example
{
"chain_id": 1,
"dataset_id": "0304",
"is_reorg": false,
"data": {
"block_number": 12345680,
"block_time": "2025-10-29T00:01:23Z",
"tx_index": 5,
"log_index": 2,
"trace_address": null,
"from_address": "0000000000000000000000000000000000000000",
"to_address": "0000000000000000000000000000000000000001",
"token_address": "c02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
"amount_raw": "1000000000000000000",
"amount_adj": "1.0",
"token_id": null,
"transfer_type": 2,
"_tracing_id": "0304000000000000000000000000000000000001",
"_parent_tracing_ids": [
"0102000000000000000000000000000000000001",
"0201000000000000000000000000000000000001"
],
"_created_at": "2025-11-11T18:42:15.123Z",
"_updated_at": "2025-11-11T18:42:15.123Z"
}
}
Messages
No examples found{
"action": "<string>",
"chain_id": 123,
"dataset_id": "<string>"
}{
"action": "<string>",
"chain_id": 123,
"dataset_id": "<string>",
"status": "<string>",
"error": {
"code": "<string>",
"message": "<string>",
"severity": "<string>",
"retryable": true
}
}{
"action": "<string>",
"chain_id": 123,
"dataset_id": "<string>",
"status": "<string>",
"error": {
"code": "<string>",
"message": "<string>",
"severity": "<string>",
"retryable": true
}
}{
"chain_id": 123,
"dataset_id": "<string>",
"is_reorg": true,
"data": {
"block_number": 123,
"tx_index": 123,
"from_address": "<string>",
"to_address": "<string>",
"token_address": "<string>",
"transfer_type": "<string>",
"amount_raw": "<string>",
"_tracing_id": "<string>"
}
}subscribe
type:object
unsubscribe
type:object
subscribe_response
type:object
unsubscribe_response
type:object
update
type:object
Last modified on April 6, 2026
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