Configuring

Introduction

As we previously saw, in order to get a hold on a precious session, one would need to call one of the 2 available static-factory methods:

• ApiSession.default(params?, path?)
• ApiSession.buildFrom(StratoContext)

Both of them return a Promise which, when resolved, give back the ApiSession instance to play with. In fact, ApiSession.buildFrom(StratoContext) is wrapped by it's default sibling which, we could argue, will most likely probability end up to being used the most.

This section describes the arguments of ApiSession.default and how they can be used to obtain a session to operate on.

The default session can be procured in one of the 4 following ways:

• ApiSession.default() - run most often with no arguments at all, in which case it will try to load the parameters from the environment file present at HEDERAS_ENV_PATH environment-variable path or, if not specified, default loading the .env from repo-root. This is basically equivalent to calling ApiSession.default({}, path = process.env.HEDERAS_ENV_PATH || '.env')
• ApiSession.default(path) - parse params present at path env-file location. This ends up running ApiSession.default({}, path)
• ApiSession.default(params) - build the desired context unpacking a runtime representation of a json object. This is equivalent to running ApiSession.default(params, path = process.env.HEDERAS_ENV_PATH || '.env')
• ApiSession.default(params, path) - creates a session-execution context (StratoContext) by doing a parameter resolution over the provided arguments

Following is a table detailing all the object-parameters along with their environmental variables counterparts which can be used to bootstrap a Venin session.

Big table o' parameters

Environment Variable	Parameter Property	Required	Type	Default	Description
HEDERAS_WALLET_CONTROLLER_DEFAULT_PRIVATE_KEY	wallet.controller.default.operatorKey	6	-	-	The private-key used by the operators when switching accounts on a Sdk wallet using a DefaultPrivateKeyWalletController
HEDERAS_WALLET_CONTROLLER	wallet.controller.type	-	Hedera, DefaultPrivateKey	Hedera	The type of wallet-controller deployed. It's basically laying out the foundation of wallet-integration since a controller can propagate either an account-change or a network change.
HEDERAS_WALLET_TYPE	wallet.type	No	Sdk	Sdk	The wallet type used for the underlying session interactions (see wallets guide)
HEDERAS_WALLET_WINDOW_PROPERTY_NAME	wallet.window.propName	No	string	hedera	When bundling, the property location of the HIP-338 compliant wallet definition available on the global, window object
HEDERAS_CONTRACTS_INCLUDED_PREFIXES	-	No	5	contracts	The places to search for imported contract paths from within a solidity code. The contract's parent folder is the first one being searched, followed by the project's node_modules and then, if nothing matches, the rest of the included prefixes are looked at in the order in which they are defined
HEDERAS_CONTRACTS_RELATIVE_PATH	-	No	path	contracts	The name of the folder relative to the project root directory where all the solidity contracts are expected to reside. This is used when Venin is doing the contract compiling of a given relative-pathed contract
HEDERAS_DEFAULT_CONTRACT_CREATION_GAS	session.defaults.contractCreationGas	No	number	150000	The default amount spent for creating a contract on the network
HEDERAS_DEFAULT_CONTRACT_REQUESTS_RETURN_ONLY_RECEIPTS	session.defaults.onlyReceiptsFromContractRequests	No	boolean	true	true to return only receipts for all state-mutating/transactions live-contract call, false otherwise. Contract queries (non-mutating calls) are not affected by this param. If desired, can be tweaked by the onlyReceipt contract-call meta-argument at an individual level.
HEDERAS_DEFAULT_CONTRACT_TRANSACTION_GAS	session.defaults.contractTransactionGas	No	number	169000	The default amount given when executing a contract transaction
HEDERAS_DEFAULT_EMIT_CONSTRUCTOR_LOGS	session.defaults.emitConstructorLogs	No	boolean	true	true to emit the constructor logs at contract-creation time, false otherwise
HEDERAS_DEFAULT_EMIT_LIVE_CONTRACT_RECEIPTS	session.defaults.emitLiveContractReceipts	No	boolean	false	true to ask for and emit the receipts originating from live-contract calls, false otherwise
HEDERAS_DEFAULT_PAYMENT_FOR_CONTRACT_QUERY	session.defaults.paymentForContractQuery	No	number	20000000	The default amount of tinybars payed for doing a contract query call. If not specified, relies on an upper limit given by the Hedera's SDK which is, currently, 1ℏ ( might change in the future, see #11 )
HEDERAS_NETWORK	network.name	Yes	previewnet, testnet, mainnet, customnet	-	The network profile to use
HEDERAS_NODES	network.nodes	4	3	-	A condensed address-book representation of the network nodes (see3)
HEDERAS_OPERATOR_ID	wallet.hedera.operatorId	2	-	-	The account-id of the operator running a Sdk wallet
HEDERAS_OPERATOR_KEY	wallet.hedera.operatorKey	2	-	-	The operator private-key of the operator running a Sdk wallet
HEDERAS_LOGGER_LEVEL	logger.level	No	error, warn, info, verbose, debug, silly	info	The logger sensitivity 1
HEDERAS_LOGGER_ENABLED	logger.enabled	No	boolean	false	true to enable the logger, false otherwise
HEDERAS_ENV_PATH	-	No	path	.env	The path of the .env like file used to source the config parameters from

Parameters resolution

The default context parameters are being resolved in the following order:

• First, the runtime object-argument is checked and if a config property is present there, that's the one being used otherwise
• If process.env (nodejs-case) contains that equivalent environment variable, that is the one which will be used else
• If the HEDERAS_ENV_PATH environment file path has been supplied, exists and contains the same keys expected in process.env, it will be used else
• If a .env file exists and it contains the same key expected in process.env, that's one is being used.

If none of the above conditions are true and the parameter is not mandatory, the default value is loaded or an error eventually propagates.

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1. see https://github.com/winstonjs/winston#logging↩
2. required if HEDERAS_WALLET_TYPE/wallet.type is Sdk (the default)↩
3. a comma separated string of node-network addresses having the following format : <ip>:<port>#<account_id> eg 127.0.0.2:52111#3 to make an address-book of one node located at 127.0.0.1, port 52111 having account-id 0.0.3↩
4. required if HEDERAS_NETWORK/network.name is customnet↩
5. a comma separated list of relative folder paths to look at when importing a relative solidity contract-file from within one of the contracts that we wish to compile↩
6. required if HEDERAS_WALLET_CONTROLLER_TYPE is DefaultPrivateKey↩