# Open-source crypto tax software

> rotki approaches crypto taxes differently from most tools: it is open source, and it runs on your computer. That combination is deliberate. You are not uploading your transaction history to a service and trusting calculations you cannot see; you can read exactly how rotki turns your trades and on-chain activity into a tax report.

rotki approaches crypto taxes differently from most tools: it is open source, and it runs on your computer. That combination is deliberate. You are not uploading your transaction history to a service and trusting calculations you cannot see; you can read exactly how rotki turns your trades and on-chain activity into a tax report.

## Why open source matters for taxes

Tax calculations involve judgement calls: which cost-basis method to use, how to treat a transfer between your own wallets, how to value a DeFi reward. With closed software you have to take the vendor's word for how those decisions are made. Because rotki is open source, the accounting logic is public and auditable. If a number looks wrong, you can trace why.

## How rotki produces your report

rotki builds your history from the exchanges and wallets you add, decodes on-chain activity into readable events, and then applies your accounting settings to calculate gains and losses. It produces a detailed, exportable report of taxable events for the period you choose. All of that happens locally on your machine.

## Cost-basis methods rotki supports

rotki supports four cost-basis methods: FIFO (first in, first out), LIFO (last in, first out), HIFO (highest in, first out) and ACB (average cost basis). You pick the method and the accounting period in settings, and rotki applies it locally when it builds the report. The profit-and-loss report and its underlying events can be exported as CSV for your records or your accountant.

## What rotki does and does not do

rotki gives you accurate, auditable accounting and a clear report of taxable events. It does not pre-fill your country's specific government forms, and it is not tax advice. If you want to understand and own your crypto accounting while keeping it private, running open-source software locally is a solid basis for that.