Stellar Tx signers inspector

Discover required signers, weights, and build optimal signature schema for Stellar transactions and accounts.

Usage

npm i @stellar-expert/tx-signers-inspector

Analyze transaction signers

To analyze transaction signature requirements, we need to build signers schema first:

import {inspectTransactionSigners} from '@stellar-expert/tx-signers-inspector'
//build signatures schema
const schema = await inspectTransactionSigners(tx)

Discovering all signers that can potentially sign a transaction

Method getAllPotentialSigners() returns all signers for all accounts used as source in either the transaction itself or any of its operations.

schema.getAllPotentialSigners()
//returns something like ['GA7...K0M', 'GCF...DLP', 'GA0...MMR']

Discovering optimal transaction signers

Method discoverSigners() returns the list of the optimal signers to use. It automatically detects weights and performs an advanced lookup to find the best signing schema in terms of the minimum signers count. This is especially useful for complex transactions containing multiple operations with different sources.

schema.discoverSigners()
//returns something like ['GA7...K0M']

Discovering optimal transaction signers with a restricted list of available signers

Calling discoverSigners(availableSigners) with availableSigners argument returns the optimal signature schema (just like calling it without arguments) respecting the restrictions list. Only explicitly provided signers will be used for a schema lookup.

schema.discoverSigners(['GCF...DLP', 'GA0...MMR', 'GBP...D71'])
//returns something like ['GCF...DLP', 'GA0...MMR']

Checking signing feasibility for a transaction

Method checkFeasibility(availableSigners) verifies that the transaction can be fully signed using a given set of available signers. It returns true if the total weight of the provided signers is sufficient to fully sign the transaction and false otherwise.

schema.checkFeasibility(['GCF...DLP', 'GA0...MMR', 'GBP...D71'])
//returns true
schema.checkFeasibility(['GA0...MMR', 'GBP...D71'])
//returns false

Avoiding TX_BAD_AUTH_EXTRA errors

Stellar protocol forbids transactions signed with excessive number of signers. Adding more signatures than needed for a transaction results in a TX_BAD_AUTH_EXTRA error. In complex cases it's not easy to detect such situations automatically and avoid excessive signatures. Method checkAuthExtra(availableSigners) returns a list of signers that can cause the TX_BAD_AUTH_EXTRA error.

schema.checkAuthExtra(['GCF...DLP', 'GA0...MMR'])
//returns []
schema.checkAuthExtra(['GA7...K0M', 'GCF...DLP', 'GA0...MMR'])
//returns ['GCF...DLP', 'GA0...MMR']

Analyze account signers

Accounts signing requirements can be analyzed similar to transactions.

import {inspectAccountSigners} from '@stellar-expert/tx-signers-inspector'
//build signatures schema for an account
const schema = await inspectAccountSigners('GDF...ER2')

Discovering all account signers

Method getAllPotentialSigners() returns all account signers.

schema.getAllPotentialSigners()
//returns something like ['GA7...K0M', 'GCF...DLP', 'GA0...MMR']

Discovering optimal account signers for a given threshold

Method discoverSigners(weight) returns the list of the optimal signers to match the required signatures weight.

schema.discoverSigners('low')
//returns something like ['GA7...K0M']

Discovering optimal account signers for a given threshold with a restricted list of available signers

Calling discoverSigners(weight, availableSigners) with availableSigners argument returns the optimal signature schema to match the required signatures weight (just like calling it without arguments) respecting the restrictions list. Only explicitly provided signers will be used for a schema lookup.

schema.discoverSigners('med', ['GCF...DLP', 'GA0...MMR', 'GBP...D71'])
//returns something like ['GCF...DLP', 'GA0...MMR']

Checking account signing feasibility for a given threshold

Method checkFeasibility(weight, availableSigners) verifies that the transaction with a given threshold can be fully signed using a given set of available signers. It returns true if the total weight of the provided signers is sufficient to meet the threshold requirements and false otherwise.

schema.checkFeasibility('med', ['GCF...DLP', 'GA0...MMR'])
//returns true
schema.checkFeasibility('high', ['GCF...DLP', 'GA0...MMR'])
//returns false

Avoiding TX_BAD_AUTH_EXTRA errors for a given account threshold

Method checkAuthExtra(weight, availableSigners) returns a list of signers that can cause the TX_BAD_AUTH_EXTRA error when signing a transaction the requires a given account threshold.

schema.checkAuthExtra('med', ['GCF...DLP', 'GA0...MMR'])
//returns []
schema.checkAuthExtra('med', ['GA7...K0M', 'GCF...DLP', 'GA0...MMR'])
//returns ['GCF...DLP', 'GA0...MMR']

Options

The analyzers automatically fetch the required accounts information from Horizon. By default, https://horizon.stellar.org is used. To use testnet Horizon address or you own server, provide horizon options parameter in the inspectTransactionSigners() or inspectAccountSigners() method call:

//use testnet Horizon server instead of the default address
const schema = await inspectTransactionSigners(tx, 
    {horizon: 'https://horizon-testnet.stellar.org'})

To deal with cases where some account doesn't exist yet, it's possible to provide accounts information directly:

//provide account information directly
const schema = await inspectTransactionSigners(tx, {accountsInfo: [
    {
      account_id: 'GAU...DOE',
      id: 'GAU...DOE',
      sequence: '2',
      subentry_count: 0,
      signers: [
        {
          type: 'ed25519_public_key',
          key: 'GAU...DOE',
          weight: 1
        }
      ],
      thresholds: {
        low_threshold: 0,
        med_threshold: 0,
        high_threshold: 0
      }
    }
]})

Tests

npm run test