https://github.com/blockdaemon/demo-event-streaming
Blockdaemon Chain Watch - streaming on-chain events in real-time
https://github.com/blockdaemon/demo-event-streaming
Last synced: about 2 months ago
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Blockdaemon Chain Watch - streaming on-chain events in real-time
- Host: GitHub
- URL: https://github.com/blockdaemon/demo-event-streaming
- Owner: Blockdaemon
- License: other
- Created: 2024-04-11T02:01:32.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2024-11-22T17:35:54.000Z (5 months ago)
- Last Synced: 2025-03-03T03:11:43.006Z (about 2 months ago)
- Language: Go
- Size: 4.88 KB
- Stars: 0
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Blockdaemon Chain Watch - streaming on-chain events in real-time
- In this example we'll use the Event Streaming service to monitor any on-chain transfers to the PEPE smart contract
- Requirements:
- Go lang
- Blockdaemon REST API key
- Reverse proxy service
- [HTTPie](https://httpie.io/cli) & [jq](https://jqlang.github.io/jq/download/) CLI tools
- Docs: https://docs.blockdaemon.com/reference/events-introduction
```mermaid
sequenceDiagram
participant Customer
participant webhook as Customer Webhook
Server
participant A as Event Streaming
API
participant B as Blockdaemon
Indexing Stack
participant C as RPC Node
Cluster
Customer->>A: Create webhook target
A->>A: Create target
A->>webhook: Target status connected
Customer->>A: Create matching rule
A->>B: Apply rule
loop
C->>B: Consume blockchain data
B->>A: Adds messages to target topic
end
loop
A->>A: Read messages for rule
A->>webhook: Send formatted message to target
end
```
## Step 1. Run webhook receiver (includes a Challenge Response Check)
- the sample webhook server will respond to CRC token checks with the secret "mysecret123"
- all webhook posts will be printed to the console
- the service will listen on port 8082
```shell
go run webhookserver.go
```
## Step 2. Publish the webhook server socket
- [ngrok reverse proxy](https://ngrok.com/docs/getting-started/) is used as an example to publish the server
- register for ngrok account or publish through your own methods
```shell
# set the Webhook Server FQDN
export WEBHOOKSERVERFQDN=XXXX.ngrok-free.app
# start the reverse proxy
ngrok http --domain=$WEBHOOKSERVERFQDN http://localhost:8082
```
## Step 3.
```shell
# set Blockdaemon API key variable
export XAPIKey=XXXXX
# note Event Streaming protocol capabilities
http GET https://svc.blockdaemon.com/streaming/v2/ \
X-Api-Key:$XAPIKey
# create webhook target - set the ngrok domain and note secret matches webhook server
TARGET_ID=$(http POST https://svc.blockdaemon.com/streaming/v2/targets \
X-Api-Key:$XAPIKey \
name='smartcontract webhook target' \
description='Sample Go Webhookserver target' \
max_buffer_count:=100 \
settings:='{"destination": "https://'"$WEBHOOKSERVERFQDN"'", "method": "POST", "secret": "mysecret123"}' \
type='webhook' \
| jq -r .id)
# get the webhook target status - should be "connected"
http GET https://svc.blockdaemon.com/streaming/v2/targets \
X-Api-Key:$XAPIKey
```
## Step 4.
```shell
# create a smart contract address variable key
VARIABLE_ID=$(http POST https://svc.blockdaemon.com/streaming/v2/variables \
X-Api-Key:$XAPIKey \
name='smart contract addresses' \
description='smart contract addresses' \
type='string' \
| jq -r .id)
# set the variable key value to the PEPE token contract address 0x6982508145454Ce325dDbE47a25d4ec3d2311933
http POST https://svc.blockdaemon.com/streaming/v2/variables/$VARIABLE_ID/values \
X-Api-Key:$XAPIKey \
value='0x6982508145454Ce325dDbE47a25d4ec3d2311933'
```
## Step 5.
```shell
# create rule combining the webhook target, the blockchain (Ethereum Mainnet), and the target address
# review the different output template options here: https://docs.blockdaemon.com/docs/advanced-templating#using-predefined-templates
RULE_ID=$(http POST https://svc.blockdaemon.com/streaming/v2/rules \
X-Api-Key:$XAPIKey \
name='Ethereum mainnet rule' \
description='Ethereum mainnet rule' \
network='mainnet' \
protocol='ethereum' \
condition:='[{"variable_type": "address", "variable_id": "'"$VARIABLE_ID"'"}]' \
target="$TARGET_ID" \
condition_type='match_var' \
is_active:=true \
template='UNIFIED_V1' \
| jq -r .id)
# validate the rule
http GET https://svc.blockdaemon.com/streaming/v2/rules \
X-Api-Key:$XAPIKey
```
## Step 6.
Observe the different webhook events in the webhookserver output. Example below of confirmed_tx event:
```json
{
"data": {
"accessList": [],
"additionalFields": {
"yParity": "0x0"
},
"blockHash": "0xfc57c0ce8f94d133863f21dda0943b553e792e5fd1b9e687c680aa1b286bfd1f",
"blockNumber": "0x12b845b",
"chainId": "0x1",
"contractAddress": null,
"creates": null,
"cumulativeGasUsed": "0x1bfc64d",
"effectiveGasPrice": "0x2bad348ab",
"from": "0xcAFb5420CE411476ef43CCeEa50e71A95b6Ad5B0",
"gas": "0x163ed",
"gasPrice": "0x2bad348ab",
"gasUsed": "0xd986",
"hash": "0x06424f8c03c746ea1ccf3167d454a4ca54351bb4b179c9b3803455872cc31248",
"input": "0xa9059cbb00000000000000000000000031da1b45d2570b5722618b8b43b0c805114048ee00000000000000000000000000000000000000000031c7ea725f3bca431e6000",
"logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000080000000000000008000000000000000000000000000000000000000000000000000000000000000000000000004000000000000000000010000004000000000000000000000000000000000000000000000000000000000200000000000040000000000000000000000000000000002000000000000000000000000000000002000000000400000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000008000",
"maxFeePerGas": "0x40c933ae2",
"maxPriorityFeePerGas": "0xecd10",
"nonce": "0x3d6",
"publicKey": null,
"r": "0x2b12ee7984f96db6cf16a190e257caa0392fa8961243488ff07caa4931adaffe",
"raw": null,
"root": null,
"s": "0x6ed8f306cdfa24c4aea4f30ec5cfb853dfe90adc6d32db37d60195e36e3b1422",
"status": "0x1",
"timestamp": 1712799383,
"to": "0x6982508145454Ce325dDbE47a25d4ec3d2311933",
"transactionIndex": "0xd0",
"type": "0x2",
"uuid": "8e695b82-7ed3-4ab0-894d-bce7a91077a6",
"v": "0x0",
"value": "0x0"
},
"event_type": "confirmed_tx",
"network": "mainnet",
"protocol": "ethereum",
"rule_id": "34b775e7-4425-4487-9181-0436022588fc",
"target_id": "9c6b6a09-dd23-40b7-bb57-7aa0673f2a20"
}
```
where:
```json
data.input: 0xa9059cbb00000000000000000000000031da1b45d2570b5722618b8b43b0c805114048ee00000000000000000000000000000000000000000031c7ea725f3bca431e6000
```
ABI decodes to:
```json
"definition": "transfer(address,uint256)",
"decodedInputs": [
"0x31DA1B45d2570B5722618B8b43b0C805114048EE",
"60181440870692720000000000"
]
```
meaning `60181440870692720000000000` PEPE was transferred from `0xcAFb5420CE411476ef43CCeEa50e71A95b6Ad5B0` to `0x31DA1B45d2570B5722618B8b43b0C805114048EE`
## Step 7.
```shell
# terminate the reverse proxy to simulate real-world failure and observe the current_buffer_count increase
http GET https://svc.blockdaemon.com/streaming/v2/targets \
X-Api-Key:$XAPIKey
[
...
"current_buffer_count": 35,
"description": "Sample Go Webhookserver target",
...
]
```
## Step 8.
```shell
# delete the rule to halt further notifitions
http DELETE https://svc.blockdaemon.com/streaming/v2/rules/$RULE_ID \
X-Api-Key:$XAPIKey
```