\n\n# Multi-Chain Client\n\n\nMCC or Multi-Chain Client is a Typescript library that:\n* allows querying nodes from any blockchain in a unified manner.\n* Retrieved data is encapsulated in objects that hold all the original information and allow adding static, named properties.\n* Implements a set of common methods used in FDC to calculate accounting information, such as balances, source and destination addresses, etc.\n\nThe main focus of the library is the block and transaction data structures and their associated methods for FDC attestation. The library is designed to be used in the Flare ecosystem but can also be used independently for blockchain data querying and processing.\n\n## Underlying nodes\n\nWe recommend to deploy nodes from our docker [repo](https://github.com/flare-foundation/connected-chains-docker)\n\n## Development notes\n\n[Want to contribute?](./CONTRIBUTING.md)\n\n## Security\n\nIf you have found a possible vulnerability please see [SECURITY.md](./SECURITY.md)\n\n## Installation\n\nThe package is published to the NPM registry as [`@flarenetwork/mcc`](https://www.npmjs.com/package/@flarenetwork/mcc).\n\n### Verification of published package\n\nEach release is published with [NPM provenance](https://docs.npmjs.com/viewing-package-provenance),\nwhich links the published package to the exact source commit and CI pipeline that built it.\n\nTo verify the integrity of the published package, you can use the following command:\n\n```bash\nnpm audit signatures\n```\n\nThis command checks the registry signatures and provenance attestations.\nIf a package has missing or invalid signatures or attestations, it returns an error.\nThis could indicate that a package has been tampered with.\n\n# How to use\n\nThe most basic use of the MCC client is to query blocks and transactions from different blockchains. The code below demonstrates how to query a transaction from the Bitcoin and Algorand networks, showcasing the unification of query methods as well as the unification of responses.\n\nIn the MCC, connections to each blockchain are made through a different [MCC object](./mccClient/mccClient.md).\n\n> **NOTE:**\n> Networks are accessed through RPC endpoints that usually require some type of credentials.\n> To start a connection credentials must be provided through the `MCCCreate` object, which is different depending on the connected chain.\n>\n> [Find more details here](./connectConfig.md).\n\nLet's take a look at the minimal example to query a block and a transaction from the Bitcoin network by their height and transaction id (`txid`) respectively:\n\n```javascript\n// Configuration object\nconst connectConfig = {\n url: \"https://myAwesomeBtcNode.com/\",\n username: \"user\",\n password: \"pass\",\n};\n\n// MCC object used to connect to Bitcoin node\nconst MccClient = new MCC.BTC(connectConfig);\n\n// Query block by its height\nconst block = await MccClient.getBlock(750_000);\n\n// Log some details about the queried block\n// Block height\nconsole.log(block.number); // => 750000\n// Block hash\nconsole.log(block.blockHash); // => ''\n\n// Query transaction\nconst transaction = await MccClient.getTransaction(\"\");\n\n// Log some details about the queried transaction\n// Transaction timestamp\nconsole.log(transaction.unixTimestamp); // => unixTimestamp\n// Source addresses\nconsole.log(transaction.sourceAddresses); // => [, , ...]\n```\n\nNow, to get block and transaction objects from a totally different blockchain such as Ripple, you only need to change the initialization of the MCC client, everything else remains the same.\n\n```javascript\n// Configuration object\nconst connectConfig = {\n url: \"https://myAwesomeXrpNode.com/\",\n};\n\n// MCC object used to connect to Ripple node\nconst MccClient = new MCC.XRP(connectConfig);\n\n// Query block by its height\nconst block = await MccClient.getBlock(750_000);\n\n// Log some details about the queried block\n// Block height\nconsole.log(block.number); // => 750000\n// Block hash\nconsole.log(block.blockHash); // => ''\n\n// Query transaction\nconst transaction = await MccClient.getTransaction(\"\");\n\n// Log some details about the queried transaction\n// Transaction timestamp\nconsole.log(transaction.unixTimestamp); // => unixTimestamp\n// Source addresses\nconsole.log(transaction.sourceAddresses); // => []\n```\n","readmeFilename":"README.md"}
![\"Flare](\"https://content.flare.network/Flare-2.svg\")
\n