Independent On-Chain Verification Engine
Free to use. No account required. Free tier: up to 800 transactions, 3 audits per 7 days. TrueBasis deterministically reconstructs transaction structure across Bitcoin, Solana, and 20 EVM chains — classifying swaps, lending, flash loans, staking, NFTs, bridges, wraps, airdrops, governance, and more. Session detection links multi-transaction lending and vault lifecycles. Structured audit pack your CPA can actually use.
NOT TAX SOFTWARE. TrueBasis does not calculate gains, losses, or cost basis. It does not determine tax treatment, provide legal or tax advice, or assist with filing. It provides structural verification and reconciliation support only.
KNOWN LIMITATION. Transactions routed through privacy protocols (zero-knowledge mixers, private L2s, confidential transfer schemes) obscure on-chain state by design. TrueBasis cannot classify what the blockchain does not expose. Such transactions will appear as unclassified or incomplete in your audit output.
What TrueBasis is
Whether you're a DeFi user trying to understand what your tax software actually did with your transactions, or a CPA verifying a client's crypto history — TrueBasis reads on-chain state directly and tells you what the blockchain recorded.
It reconstructs transaction intent from method selectors and logs, and flags structural contradictions when your tax software output doesn't match reality.
Process
01 — Ingest
Provide one or more wallet addresses — EVM, Bitcoin, or Solana. Select EVM chains to scan; Bitcoin and Solana are detected automatically from address format. Set a date range. Optionally upload an owned-addresses file, exchange CSVs, or a tax software export for mismatch detection.
02 — Verify
TrueBasis fetches transactions across up to 20 EVM chains, Bitcoin, and Solana — enriches each with full receipt data, method selectors, event logs, and normalized transfer events — then runs the classification engine. 31+ structural class IDs. Deterministic rules, not ML inference. Protocol name recorded in evidence for every identified interaction.
03 — Deliver
A ZIP archive is generated containing a formatted Excel report, a CPA-readable summary, a flagged review list sorted by risk level, and — when a tax software export was provided — a mismatch report with contradiction explanations.
Classification Engine
TrueBasis assigns every on-chain transaction a structural classification based on deterministic rules — method selectors, known protocol addresses, event logs, and transfer patterns. No machine learning. No guesswork. Each classification includes a confidence level, a risk level, and protocol-level evidence.
Exchanges & Liquidity
Lending
Staking & Wrapping
NFTs
Session Detection
Transfers
Protocol & Utility
Review Required
Protocol name recorded in evidence for all identified DEX, lending, and staking interactions. Session detection links multi-transaction lending and vault lifecycles — open positions flagged for CPA review. Full classification detail available in the audit report.
Supported Networks
Coverage spans Ethereum mainnet, all major L2s, and emerging EVM-compatible networks — plus Bitcoin and Solana. Each chain is validated end-to-end through the full audit pipeline before being listed as stable.
Data sourced directly from
blockchain explorers and
RPC endpoints on each chain.
Fallback coverage on all networks.
Bitcoin + Solana + 20 EVM — in production
Privacy protocol transactions (ZK mixers, private L2s, confidential transfers) cannot be classified — on-chain state is intentionally obscured. These will appear as unclassified in audit output.
Who uses TrueBasis
You've been active on-chain for years. Your tax software spat out a number and you have no idea if it's right. TrueBasis shows you exactly what each transaction was — in plain structural terms — so you can spot misclassifications before they become your problem.
You already have your client's CoinTracker export. TrueBasis verifies it against on-chain state and surfaces every structural contradiction — before you sign off.
Multi-client audit support. Upload exchange CSVs from Binance, Coinbase, Kraken, and others alongside on-chain data. Each source is labeled in every output file.
Deliverables
truebasis_audit_report.xlsx
Formatted Excel report. The primary CPA deliverable.
truebasis_audit_summary.csv
CPA-friendly transaction summary with Source labels.
review.csv
Items requiring human review, sorted by risk level.
mismatch_report.csv
Generated when a tax software CSV is uploaded. Flags every structural contradiction with risk level and explanation.
truebasis_audit_pack.md
Human-readable narrative audit summary.
truebasis_client_summary.pdf
One-page client-facing summary. Classification breakdown, risk summary, and mismatch count — ready to attach to a client deliverable.
flags.json
Machine-readable source of truth. Structured data for every transaction classified.
New to these terms? See the transaction glossary or the results guide.