Allows Cactus nodes to connect to a Besu ledger.

Usage no npm install needed!

<script type="module">
  import elenaizaguirreCactusPluginLedgerConnectorBesu from 'https://cdn.skypack.dev/@elenaizaguirre/cactus-plugin-ledger-connector-besu';



This plugin provides Cactus a way to interact with Besu networks. Using this we can perform:

  • Deploy Smart-contracts through bytecode.
  • Build and sign transactions using different keystores.
  • Invoke smart-contract functions that we have deployed on the network.


Getting Started

Clone the git repository on your local machine. Follow these instructions that will get you a copy of the project up and running on your local machine for development and testing purposes.


In the root of the project to install the dependencies execute the command:

npm run comfigure


In the project root folder, run this command to compile the plugin and create the dist directory:

npm run tsc


The sequence diagrams for various endpoints are mentioned below


run-transaction-endpoint sequence diagram The above diagram shows the sequence diagram of run-transaction-endpoint. User A (One of the many Users) interacts with the API Client which in turn, calls the API server. API server then executes transact() method which is explained in detailed in the subsequent diagrams. run-transaction-endpoint transact() method The above diagram shows the sequence diagraom of transact() method of the PluginLedgerConnectorBesu class. The caller to this function, which in reference to the above sequence diagram is API server, sends RunTransactionRequest object as an argument to the transact() method. Based on the type of Web3SigningCredentialType, corresponsing responses are sent back to the caller.
run-transaction-endpoint transactCactusKeychainRef() method The above diagram shows transactCactusKeychainReference() method being called by the transact() method of the PluginLedgerConnector class when the Web3SigningCredentialType is CACTUSKEYCHAINREF. This method inturn calls transactPrivateKey() which calls the signTransaction() method of web3 library. runtransaction-endpoint transactPrivateKey() method The above diagram shows transactPrivateKey() method being called by the transact() method of the PluginLedgerConnector class when the Web3SigningCredentialType is PRIVATEKEYHEX. This method then calls the signTransaction() method of the web3 library. run-transaction-endpoint transactSigned() method The above diagram shows transactSigned() method being called by the transact() method of the PluginLedgerConnector class when the Web3SigningCredentialType is NONE. This method calls the sendSignedTransaction() of the web3 library and then calls pollForTxReceipt() method. run-transaction-endpoint pollForTxReceipt() method The above diagram shows pollForTxReceipt() method which is called by the transactSigned() method as described in the previous sequence diagram. This method waits for the block confirmation in a loop and then sends the corresponding response back to the caller.


To use this import public-api and create new PluginFactoryLedgerConnector. Then use it to create a connector.

const factory = new PluginFactoryLedgerConnector({
    pluginImportType: PluginImportType.LOCAL,
  const connector: PluginLedgerConnectorBesu = await factory.create({
    instanceId: uuidv4(),
    pluginRegistry: new PluginRegistry(),

You can make calls through the connector to the plugin API:

async invokeContract(req: InvokeContractV1Request):Promise<InvokeContractV1Response>;
async transactSigned(rawTransaction: string): Promise<RunTransactionResponse>;
async transactPrivateKey(req: RunTransactionRequest): Promise<RunTransactionResponse>;
async transactCactusKeychainRef(req: RunTransactionRequest):Promise<RunTransactionResponse>;
async deployContract(req: DeployContractSolidityBytecodeV1Request):Promise<RunTransactionResponse>;
async signTransaction(req: SignTransactionRequest):Promise<Optional<SignTransactionResponse>>;

Call example to deploy a contract:

const deployOut = await connector.deployContract({
  web3SigningCredential: {
    ethAccount: firstHighNetWorthAccount,
    secret: besuKeyPair.privateKey,
    type: Web3SigningCredentialType.PrivateKeyHex,
  bytecode: SmartContractJson.bytecode,
  gas: 1000000,

The field "type" can have the following values:

enum Web3SigningCredentialType {
    NONE = 'NONE'

Extensive documentation and examples in the readthedocs (WIP)

Building/running the container image locally

In the Cactus project root say:

DOCKER_BUILDKIT=1 docker build -f ./packages/cactus-plugin-ledger-connector-besu/Dockerfile . -t cplcb

Build with a specific version of the npm package:

DOCKER_BUILDKIT=1 docker build --build-arg NPM_PKG_VERSION=0.4.1 -f ./packages/cactus-plugin-ledger-connector-besu/Dockerfile . -t cplcb

Running the container

Launch container with plugin configuration as an environment variable:

docker run \
  --rm \
  --publish 3000:3000 \
  --publish 4000:4000 \
  --env PLUGINS='[{"packageName": "@hyperledger/cactus-plugin-ledger-connector-besu", "type": "org.hyperledger.cactus.plugin_import_type.LOCAL",  "options": {"rpcApiHttpHost": "http://localhost:8545", "instanceId": "some-unique-besu-connector-instance-id"}}]' \

Launch container with plugin configuration as a CLI argument:

docker run \
  --rm \
  --publish 3000:3000 \
   --publish 4000:4000 \
  cplcb \
    ./node_modules/.bin/cactusapi \
    --plugins='[{"packageName": "@hyperledger/cactus-plugin-ledger-connector-besu", "type": "org.hyperledger.cactus.plugin_import_type.LOCAL",  "options": {"rpcApiHttpHost": "http://localhost:8545", "instanceId": "some-unique-besu-connector-instance-id"}}]'

Launch container with configuration file mounted from host machine:

echo '[{"packageName": "@hyperledger/cactus-plugin-ledger-connector-besu", "type": "org.hyperledger.cactus.plugin_import_type.LOCAL",  "options": {"rpcApiHttpHost": "http://localhost:8545", "instanceId": "some-unique-besu-connector-instance-id"}}]' > cactus.json

docker run \
  --rm \
  --publish 3000:3000 \
  --publish 4000:4000 \
  --mount type=bind,source="$(pwd)"/cactus.json,target=/cactus.json \
  cplcb \
    ./node_modules/.bin/cactusapi \

Testing API calls with the container

Don't have a Besu network on hand to test with? Test or develop against our Besu All-In-One container!

Terminal Window 1 (Ledger)

docker run -p  -p  -p  -p  -p hyperledger/cactus-besu-all-in-one:latest

Terminal Window 2 (Cactus API Server)

docker run \
  --network host \
  --rm \
  --publish 3000:3000 \
  --publish 4000:4000 \
  --env PLUGINS='[{"packageName": "@hyperledger/cactus-plugin-ledger-connector-besu", "type": "org.hyperledger.cactus.plugin_import_type.LOCAL",  "options": {"rpcApiHttpHost": "http://localhost:8545", "instanceId": "some-unique-besu-connector-instance-id"}}]' \

Terminal Window 3 (curl - replace eth accounts as needed)

curl --location --request POST '' \
--header 'Content-Type: application/json' \
--data-raw '{
    "web3SigningCredential": {
      "ethAccount": "627306090abaB3A6e1400e9345bC60c78a8BEf57",
      "secret": "c87509a1c067bbde78beb793e6fa76530b6382a4c0241e5e4a9ec0a0f44dc0d3",
      "type": "PRIVATE_KEY_HEX"
    "consistencyStrategy": {
      "blockConfirmations": 0,
      "receiptType": "NODE_TX_POOL_ACK"
    "transactionConfig": {
      "from": "627306090abaB3A6e1400e9345bC60c78a8BEf57",
      "to": "f17f52151EbEF6C7334FAD080c5704D77216b732",
      "value": 1,
      "gas": 10000000

The above should produce a response that looks similar to this:

    "success": true,
    "data": {
        "transactionReceipt": {
            "blockHash": "0x7c97c038a5d3bd84613fe23ed442695276d5d2df97f4e7c4f10ca06765033ffd",
            "blockNumber": 1218,
            "contractAddress": null,
            "cumulativeGasUsed": 21000,
            "from": "0x627306090abab3a6e1400e9345bc60c78a8bef57",
            "gasUsed": 21000,
            "logs": [],
            "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
            "status": true,
            "to": "0xf17f52151ebef6c7334fad080c5704d77216b732",
            "transactionHash": "0xc7fcb46c735bdc696d500bfc70c72595a2b8c31813929e5c61d9a5aec3376d6f",
            "transactionIndex": 0

Prometheus Exporter

This class creates a prometheus exporter, which scrapes the transactions (total transaction count) for the use cases incorporating the use of Besu connector plugin.

Prometheus Exporter Usage

The prometheus exporter object is initialized in the PluginLedgerConnectorBesu class constructor itself, so instantiating the object of the PluginLedgerConnectorBesu class, gives access to the exporter object. You can also initialize the prometheus exporter object seperately and then pass it to the IPluginLedgerConnectorBesuOptions interface for PluginLedgerConnectoBesu constructor.

getPrometheusMetricsV1 function returns the prometheus exporter metrics, currently displaying the total transaction count, which currently increments everytime the transact() method of the PluginLedgerConnectorBesu class is called.

Prometheus Integration

To use Prometheus with this exporter make sure to install Prometheus main component. Once Prometheus is setup, the corresponding scrape_config needs to be added to the prometheus.yml

- job_name: 'besu_ledger_connector_exporter'
  metrics_path: api/v1/plugins/@hyperledger/cactus-plugin-ledger-connector-besu/get-prometheus-exporter-metrics
  scrape_interval: 5s
    - targets: ['{host}:{port}']

Here the host:port is where the prometheus exporter metrics are exposed. The test cases (For example, packages/cactus-plugin-ledger-connector-besu/src/test/typescript/integration/plugin-ledger-connector-besu/deploy-contract/deploy-contract-from-json.test.ts) exposes it over and a random port(). The random port can be found in the running logs of the test case and looks like (42379 in the below mentioned URL) Metrics URL:

Once edited, you can start the prometheus service by referencing the above edited prometheus.yml file. On the prometheus graphical interface (defaulted to http://localhost:9090), choose Graph from the menu bar, then select the Console tab. From the Insert metric at cursor drop down, select cactus_besu_total_tx_count and click execute

Helper code


This file contains the various responses of the metrics.


This file contains functions encasing the logic to process the data points


This file lists all the prometheus metrics and what they are used for.

Running the tests

To check that all has been installed correctly and that the pugin has no errors run the tests:

  • Run this command at the project's root:
npm run test:plugin-ledger-connector-besu


We welcome contributions to Hyperledger Cactus in many forms, and there’s always plenty to do!

Please review CONTIRBUTING.md to get started.


This distribution is published under the Apache License Version 2.0 found in the LICENSE file.