n8n-nodes-evmstream

This is the only open-source n8n node package for real-time EVM blockchain event streaming. Never run security-critical blockchain tools from closed-source packages you cannot audit. If you can't read the code, you can lose your data. Audit this package yourself.

n8n community node package for real-time EVM blockchain event streaming via webhooks. Supports Moralis Streams and Alchemy Webhooks, giving you two independent providers for redundancy and flexibility.

First real-time blockchain event streaming nodes for n8n.

2 trigger nodes | 14+ chains | Multiple event types | Webhook signature verification | E2E tested

Supported Providers

Provider	Free Tier	Signature	Chains	Best For
Moralis Streams	~80K-120K events/mo (40K CU/day)	Keccak-256	14 EVM chains	Contract logs, decoded transfers, ABI filtering
Alchemy Webhooks	~750K events/mo (30M CU/mo, shared with RPC)	HMAC-SHA256	10 EVM networks	Address activity, NFT monitoring, GraphQL custom queries

Both providers auto-manage webhook lifecycle: stream/webhook is created when the workflow activates and deleted when it deactivates.

Installation

n8n Community Nodes (Recommended)

Go to Settings > Community Nodes in your n8n instance
Enter n8n-nodes-evmstream
Click Install

See the n8n community nodes installation guide for details.

Manual Installation

cd ~/.n8n/custom
npm install n8n-nodes-evmstream

Restart n8n after installation. See manual install docs.

Credentials Setup

Moralis Streams API Key

Field	Required	Description
API Key	Yes	Your Moralis Web3 API Key

How to get your Moralis API Key:

Go to admin.moralis.io
Sign up or log in (free account available)
Navigate to Settings > Secrets (or the API Keys section)
Copy your Web3 API Key
In n8n, create a new Moralis Streams API credential and paste the key

The same API key works for all Moralis services (Streams, Web3 Data API, etc.). Free plan: 40,000 Compute Units/day (~80K-120K webhook events/month at 10-15 CU per event).

Alchemy Webhooks Auth Token

Field	Required	Description
Auth Token	Yes	Your Alchemy Notify Auth Token

How to get your Alchemy Auth Token:

Go to dashboard.alchemy.com
Sign up or log in (free account available, no credit card required)
Navigate to the Webhooks section in the left sidebar (under Notify)
At the top of the webhooks page, find your Auth Token (click to reveal/copy)
In n8n, create a new Alchemy Webhooks API credential and paste the token

The Auth Token is account-wide (not per-app). Free plan: 30M Compute Units/month (~750K webhook events), 5 webhooks max, 25 RPS. Webhook events cost ~40 CU each (bandwidth-based at 0.04 CU/byte).

Node: Moralis Streams Trigger

Receives real-time EVM blockchain events via Moralis Streams webhooks. Automatically creates a stream when the workflow is activated and deletes it when deactivated.

Parameters

Parameter	Type	Required	Description
Chains	Multi-select	Yes	EVM chains to monitor (select one or more)
Contract Addresses	String	Yes	Comma-separated list of contract addresses to monitor
Monitor Type	Select	No	What to monitor (default: Contract Logs)
ABI	JSON	No	Contract ABI (JSON array) — only event entries are used
Topic0 Filter	String	No	Event signature hash to filter specific events

Monitor Types

Type	Value	Description
Contract Logs	`contractLogs`	Monitor emitted event logs (default)
Native Transactions	`nativeTxs`	Monitor native token transfers (ETH, MATIC, etc.)
Internal Transactions	`internalTxs`	Monitor internal contract calls
All Events	`all`	Monitor all event types

Options

Option	Type	Default	Description
Stream Description	String	`n8n workflow stream`	Description for the Moralis stream
Include All Transaction Logs	Boolean	`false`	Include all logs for matching transactions
Only Confirmed	Boolean	`false`	Only emit confirmed (not pending) events
Verify Signature	Boolean	`true`	Verify the Moralis webhook signature (Keccak-256)

Output Format

{
  "eventType": "erc20Transfers",
  "chainId": "0x1",
  "confirmed": true,
  "block": { "number": "18500000", "hash": "0xabc123...", "timestamp": "1698700800" },
  "data": {
    "transactionHash": "0xdef456...",
    "from": "0xa1b2c3d4...",
    "to": "0xf6e5d4c3...",
    "value": "2000000"
  }
}

Event types: logs, erc20Transfers, nftTransfers, txs, txsInternal.

Node: Alchemy Webhooks Trigger

Receives real-time blockchain events via Alchemy Notify webhooks. Automatically creates a webhook when the workflow is activated and deletes it when deactivated.

Parameters

Parameter	Type	Required	Description
Webhook Type	Select	Yes	Type of events to monitor
Network	Select	Yes	Alchemy network to monitor
Addresses	String	Yes*	Comma-separated addresses (*Address Activity only)
NFT Contract Address	String	Yes*	NFT contract to monitor (*NFT Activity only)
NFT Token IDs	String	No	Comma-separated token IDs to filter (NFT Activity)
GraphQL Query	String	Yes*	Custom event filter (*Custom/GraphQL only)

Webhook Types

Type	Value	Description
Address Activity	`ADDRESS_ACTIVITY`	Monitor addresses for ETH/ERC-20/ERC-721/ERC-1155 transfers
NFT Activity	`NFT_ACTIVITY`	Monitor NFT contracts for transfer events
Custom (GraphQL)	`GRAPHQL`	Arbitrary event filtering via GraphQL queries

Options

Option	Type	Default	Description
Webhook Name	String	(empty)	Name/description for the Alchemy webhook
Verify Signature	Boolean	`true`	Verify the Alchemy webhook HMAC-SHA256 signature

Output Format

{
  "eventType": "addressActivity",
  "network": "ETH_MAINNET",
  "category": "token",
  "webhookId": "wh_abc123",
  "data": {
    "fromAddress": "0xa1b2c3d4...",
    "toAddress": "0xf6e5d4c3...",
    "value": 1.5,
    "asset": "ETH",
    "category": "external"
  }
}

Supported Chains

Moralis Streams (14 chains)

Chain	Hex Chain ID	Network
Ethereum	`0x1`	Mainnet
Polygon	`0x89`	Mainnet
BSC	`0x38`	Mainnet
Avalanche	`0xa86a`	Mainnet
Arbitrum	`0xa4b1`	Mainnet
Optimism	`0xa`	Mainnet
Base	`0x2105`	Mainnet
Fantom	`0xfa`	Mainnet
Cronos	`0x19`	Mainnet
Ronin	`0x7e4`	Mainnet
Sepolia	`0xaa36a7`	Testnet
Mumbai (Amoy)	`0x13882`	Testnet
BSC Testnet	`0x61`	Testnet
Base Sepolia	`0x14a34`	Testnet

Alchemy Webhooks (10 networks)

Chain	Network ID	Network
Ethereum	`ETH_MAINNET`	Mainnet
Polygon	`MATIC_MAINNET`	Mainnet
Arbitrum	`ARB_MAINNET`	Mainnet
Optimism	`OPT_MAINNET`	Mainnet
Base	`BASE_MAINNET`	Mainnet
Ethereum Sepolia	`ETH_SEPOLIA`	Testnet
Polygon Amoy	`MATIC_AMOY`	Testnet
Arbitrum Sepolia	`ARB_SEPOLIA`	Testnet
Optimism Sepolia	`OPT_SEPOLIA`	Testnet
Base Sepolia	`BASE_SEPOLIA`	Testnet

Development

Prerequisites

Node.js 22+
npm

Setup

git clone https://github.com/pvdyck/n8n-nodes-evmstream
cd n8n-nodes-evmstream
cp .env.example .env
npm install

Environment Variables

MORALIS_API_KEY=your-moralis-api-key
ALCHEMY_AUTH_TOKEN=your-alchemy-auth-token

Scripts

Command	Description
`npm run build`	Compile TypeScript + copy icons
`npm test`	Run unit tests
`npm run test:coverage`	Run with coverage report
`npm run test:e2e`	Moralis E2E tests (spawns n8n on port 5679)
`npm run test:e2e:alchemy:tunnel`	Alchemy E2E tests with localhost.run tunnel
`npm run lint`	ESLint check
`npm run lint:fix`	ESLint auto-fix

E2E Tests

Moralis Streams (4 tests)

Test	What it validates
Stream Lifecycle	Create stream on activate, delete on deactivate
Webhook Data Processing	POST webhook payload -> normalized event items
Signature Rejection	Invalid signature -> rejected with 401
Test Webhook Handling	Moralis test payload (empty arrays) -> acknowledged, not triggered

Alchemy Webhooks (4 tests)

Test	What it validates
Webhook Lifecycle	Create webhook on activate, delete on deactivate
Webhook Data Processing	POST webhook payload -> normalized activity items
Signature Rejection	Invalid HMAC signature -> rejected
Custom GraphQL Webhook	GraphQL webhook type -> event passthrough

Design Decisions

For detailed architecture diagrams, webhook lifecycle flows, and source file maps, see IMPLEMENTATION.md.

Pure TypeScript Keccak-256

Moralis verifies webhook authenticity using Keccak-256 (the Ethereum hashing standard). Node.js crypto only provides SHA-3-256 which uses different padding (0x06 vs 0x01). This package includes a pure TypeScript BigInt-based Keccak-256 implementation — zero external dependencies.

Dual Signature Verification

Moralis: Keccak-256 hash of JSON.stringify(body) + apiKey, compared against x-signature header
Alchemy: HMAC-SHA256 of the raw request body using a per-webhook signing key, compared against x-alchemy-signature header

Webhook Trigger Pattern

Both nodes register a webhook URL with the provider. Events arrive in real-time as they happen on-chain. The webhook is automatically managed: created when the workflow activates, deleted when it deactivates.

Event Normalization

Both providers send structured payloads that are normalized into consistent n8n items with eventType, network/chain metadata, and data fields, making downstream processing straightforward.

Links & References

Moralis

Resource	URL
Moralis Streams Documentation	docs.moralis.io/streams-api
Moralis Admin Panel (API Keys)	admin.moralis.io
Moralis Pricing	moralis.com/pricing

Alchemy

Resource	URL
Alchemy Webhooks Documentation	docs.alchemy.com/reference/notify-api-quickstart
Alchemy Dashboard (Auth Token)	dashboard.alchemy.com
Alchemy Pricing	alchemy.com/pricing

n8n

Resource	URL
Community Nodes Install (GUI)	docs.n8n.io/integrations/community-nodes/installation/gui-install
Community Nodes Install (Manual)	docs.n8n.io/integrations/community-nodes/installation/manual-install

GitHub

Repository	URL
This Package	github.com/pvdyck/n8n-nodes-evmstream

License

MIT

Name		Name	Last commit message	Last commit date
Latest commit History 5 Commits
.serena		.serena
examples		examples
src		src
test		test
.env.example		.env.example
.gitignore		.gitignore
CHANGELOG.md		CHANGELOG.md
IMPLEMENTATION.md		IMPLEMENTATION.md
LICENSE		LICENSE
README.md		README.md
eslint.config.mjs		eslint.config.mjs
gulpfile.js		gulpfile.js
jest.config.js		jest.config.js
package-lock.json		package-lock.json
package.json		package.json
tsconfig.json		tsconfig.json

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n8n-nodes-evmstream

Table of Contents

Supported Providers

Installation

n8n Community Nodes (Recommended)

Manual Installation

Credentials Setup

Moralis Streams API Key

Alchemy Webhooks Auth Token

Node: Moralis Streams Trigger

Parameters

Monitor Types

Options

Output Format

Node: Alchemy Webhooks Trigger

Parameters

Webhook Types

Options

Output Format

Supported Chains

Moralis Streams (14 chains)

Alchemy Webhooks (10 networks)

Development

Prerequisites

Setup

Environment Variables

Scripts

E2E Tests

Moralis Streams (4 tests)

Alchemy Webhooks (4 tests)

Design Decisions

Pure TypeScript Keccak-256

Dual Signature Verification

Webhook Trigger Pattern

Event Normalization

Links & References

Moralis

Alchemy

n8n

GitHub

License

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