Am I Exposed?

The on-chain privacy scanner you were afraid to run.

Paste a Bitcoin address, transaction ID, xpub/descriptor, or unsigned PSBT. Get a privacy score 0-100. Find out what the blockchain reveals about you - before someone else does.

Because Chainalysis already checked.

Are you an agent? Scan a transaction right now:

npx am-i-exposed scan tx <txid> --json

Full agent docs | skill.md | MCP server

Live Site | Methodology | Privacy Guide | Agents & CLI | Setup Guide | Contributing

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Why this exists

In April 2024, OXT.me and KYCP.org went offline following the arrest of the Samourai Wallet developers. OXT was the gold standard for Boltzmann entropy analysis. KYCP made CoinJoin privacy assessment accessible to ordinary users. Both are gone.

am-i.exposed fills that gap and goes further: 31 heuristics, multi-hop chain tracing, entity matching against 30M+ known addresses, real Boltzmann entropy computed on-device via WebAssembly, interactive graph exploration, wallet-level auditing, and pre-broadcast PSBT analysis. All client-side. No backend. No tracking.

For the full technical deep-dive - every heuristic, scoring weight, academic reference, threat model, and competitor analysis - see privacy-engine.md.

How it works

1. Paste a Bitcoin address, txid, xpub/descriptor, or PSBT
2. Your browser fetches transaction data from the mempool.space API
3. 31 heuristics, 14 chain analysis modules, and entity matching against 364 known services run client-side
4. Boltzmann entropy is computed on-device using a Rust/WASM engine
5. You get a privacy score (0-100), letter grade, detailed findings, and actionable recommendations

Privacy disclosure

Your queries are not fully private. Analysis runs client-side, but your browser makes API requests to mempool.space to fetch blockchain data. Their servers can see your IP address and which addresses/transactions you look up.

For stronger privacy:

• Use Tor Browser - the tool auto-detects Tor and routes API requests through the mempool.space .onion endpoint
• Use a trusted, no-log VPN
• Wait before querying a recent transaction (timing correlation is a real risk)
• Self-host with your own mempool.space instance and Umbrel

There is no am-i.exposed backend. No analytics. No cookies. No tracking. The static site is served from GitHub Pages and has zero visibility into what is analyzed. See the Operational Security Concerns section of the privacy engine docs for the full threat model.

Privacy score

Grade	Score	Meaning
A+	90-100	Excellent - you know what you're doing
B	75-89	Good - minor issues
C	50-74	Fair - notable concerns
D	25-49	Poor - significant exposure
F	0-24	Critical - you might as well use Venmo

Scoring starts at a base of 70. Each heuristic applies a positive or negative modifier. The sum is clamped to 0-100. Only CoinJoin participation, Taproot usage, and high entropy can raise the score. Everything else can only lower it.

What it checks

Transaction analysis (paste a txid)

Core privacy heuristics

Heuristic	What it detects
Round amount detection	Round BTC/sat outputs that reveal payment vs change
Change detection	Address type mismatch, unnecessary inputs, round-amount change, output ordering
Common input ownership (CIOH)	Multi-input txs that link all your addresses to the same entity
Script type mix	Mixed address types across inputs/outputs that distinguish sender from recipient
Fee analysis	Round fee rates and RBF signaling that narrow wallet identification
Unnecessary input	Inputs that weren't needed to cover the output, exposing extra UTXOs

CoinJoin and mixing

Heuristic	What it detects
CoinJoin detection	Whirlpool (5 equal outputs), WabiSabi (20+ I/O), JoinMarket (maker/taker)
Post-mix analysis	Spending behavior after CoinJoin that undoes privacy gains
CoinJoin premix	Tx0 pre-mix transactions and their privacy implications
Anonymity set estimation	How large the set of indistinguishable participants is

Structural patterns

Heuristic	What it detects
Peel chain detection	Sequential self-transfers that slowly drain a wallet
Consolidation	Fan-in transactions merging UTXOs (links all addresses)
Exchange patterns	Deposit/withdrawal patterns typical of centralized exchanges
Entity detection	Matching against 364 known entities (exchanges, mixers, darknet, gambling)
Coin selection	Algorithm fingerprints (largest-first, knapsack, branch-and-bound)

Metadata and fingerprinting

Heuristic	What it detects
OP_RETURN metadata	Permanent embedded data (Omni, OpenTimestamps, Runes, ASCII text)
Wallet fingerprinting	nLockTime, nVersion, nSequence, BIP69 ordering, low-R signatures
Witness analysis	Witness structure patterns that identify wallet software
BIP47 notification	Payment code notification transactions
Multisig/escrow	P2SH and P2WSH multisig patterns
Coinbase detection	Mining reward transactions (structurally different from regular txs)

Entropy

Heuristic	What it detects
Boltzmann entropy (WASM)	Full link probability matrix computed on-device via Rust/WebAssembly - how many valid interpretations of the transaction exist, and the exact probability of each input-output link

Address analysis (paste an address)

Heuristic	What it detects
Address reuse	The #1 privacy killer - harshest penalty in the model
UTXO set exposure	Dust attack detection (<1000 sats), consolidation risk, UTXO count
Address type	P2TR (Taproot) > P2WPKH (SegWit) > P2SH > P2PKH (Legacy)
Spending patterns	How funds have moved through the address over time
Recurring payments	Repeated payments to the same destination (routine detection)
High activity	Addresses with unusually high transaction counts

Chain analysis (multi-hop tracing)

Module	What it does
Backward tracing	Follows inputs upstream to discover fund origins
Forward tracing	Follows outputs downstream to track where funds went
Entity proximity	Detects known entities (exchanges, mixers, darknet markets) within N hops
Taint analysis	Proportional (haircut) method tracking value flow through the tx graph
UTXO clustering	Groups addresses by common-input-ownership across the tx graph
Peel chain tracing	Follows sequential self-transfers to map wallet drain patterns
Temporal analysis	Time-based patterns across transaction history
Spending patterns	Behavioral patterns in how outputs are spent
CoinJoin quality	Structural analysis of CoinJoin effectiveness
JoinMarket analysis	JoinMarket-specific maker/taker detection
Linkability scoring	Cross-tx linkability assessment
Prospective analysis	Forward-looking risk assessment of unspent outputs

Entity detection

Transactions and addresses are checked against a database of 364 known entities across 8 categories:

Category	Count	Examples
Exchanges	169	Binance, Coinbase, Kraken, Bitfinex, Bitstamp
Payment services	50	BitPay, BTCPay, payment processors
Gambling	43	Known gambling platforms
Scams	29	Identified scam operations
Darknet markets	28	Silk Road, Hydra, and others
Mining pools	24	F2Pool, AntPool, Foundry
Mixers	11	Bitcoin Fog, ChipMixer, and others
P2P exchanges	10	Bisq, Paxful, HodlHodl

The full entity index covers 30M+ addresses using a priority-budgeted binary index. High-priority entities (OFAC-listed, darknet markets) get 100% named coverage. The core index (~0.4 MB) loads instantly; the full index (~92 MB) is available for deep scans.

Wallet analysis (paste an xpub or descriptor)

Full wallet-level privacy audit with BIP44/49/84/86 derivation support. Scans derived addresses across the gap limit and produces an aggregate privacy assessment covering address reuse, UTXO hygiene, spending patterns, fingerprint consistency, and consolidation history.

PSBT analysis (paste an unsigned PSBT)

Pre-broadcast privacy check. Analyze a transaction before signing to catch privacy issues while they can still be fixed - round amounts, script type mismatches, change detection, and wallet fingerprinting.

Cross-heuristic intelligence

The engine doesn't run heuristics in isolation. CoinJoin detection suppresses CIOH and round-amount penalties. Multisig patterns are recognized so that CIOH isn't falsely applied. Findings interact and inform each other.

Visualizations

Chart	Description
Transaction flow (Sankey)	Input-to-output flow diagram with optional Boltzmann linkability overlay
Link probability heatmap	Full Boltzmann matrix showing the probability of each input-output link
Graph explorer	OXT-style interactive transaction DAG - expand, collapse, and trace through the graph
Taint path diagram	Value flow visualization showing how taint propagates through transactions
Cluster timeline	Temporal activity chart for address transaction history
CoinJoin structure	Pool composition breakdown for Whirlpool, WabiSabi, and JoinMarket transactions
Score waterfall	Step-by-step breakdown of how the privacy score was calculated
UTXO bubble chart	Visual clustering of unspent outputs by value and age
Severity ring	Distribution of findings by severity level

Tech

• Next.js 16 static export - no server, hosted on GitHub Pages
• Client-side analysis - all heuristics, chain analysis, and entity matching run in your browser
• Boltzmann WASM - Rust-compiled WebAssembly engine computing real link probability matrices on-device, using all threads, with turbo paths for JoinMarket and more
• IndexedDB cache - confirmed transactions, outspends, and analysis results are cached locally across sessions. Repeat scans are instant, API requests are minimized, and fewer queries leave your browser
• mempool.space API only - no secondary APIs, your queries stay with one provider
• Tor-aware - auto-detects .onion and routes API requests through Tor
• TypeScript strict mode throughout
• Tailwind CSS 4 - dark theme
• visx - interactive SVG visualizations (graph explorer, taint diagrams, timelines)
• @scure/btc-signer - PSBT parsing and raw transaction decoding
• i18next - 6 languages (English, Spanish, Portuguese, German, French, Polish)
• PWA - installable, works offline after first load
• 844+ tests - Vitest unit/integration + Playwright E2E

Self-hosting

Umbrel

am-i.exposed is available as an Umbrel app, connecting directly to your own Bitcoin node and mempool.space instance for maximum privacy - no third-party API requests.

See the setup guide for instructions.

Custom mempool.space instance

Point the tool at any mempool.space-compatible API by configuring the API URL in settings. Supports self-hosted instances, eliminating all third-party data exposure.

Internationalization

Available in 5 languages:

• English (default)
• Spanish (Castilian)
• Portuguese
• German
• French
• Polish

Translations live in public/locales/. Contributions for additional languages are welcome.

CLI & Agent Integration

The analysis engine is available as a CLI tool and MCP server for terminal use and AI agent integration.

Install

npm install -g am-i-exposed

Commands

# Scan a transaction (25 heuristics + entity detection)
am-i-exposed scan tx <txid> --json

# Scan an address (reuse, UTXO hygiene, spending patterns)
am-i-exposed scan address <addr> --json

# Audit a wallet via xpub/zpub/descriptor
am-i-exposed scan xpub <zpub> --json --gap-limit 30

# Analyze a PSBT before broadcasting (no network access needed)
am-i-exposed scan psbt <file> --json

# Boltzmann entropy and link probability matrix
am-i-exposed boltzmann <txid> --json

# Multi-hop chain tracing (entity proximity, taint analysis)
am-i-exposed chain-trace <txid> --depth 3 --json

Flags

Flag	Description
--json	Structured JSON output for programmatic consumption
--fast	Skip parent tx context fetching (~6s instead of ~10s)
--network	mainnet (default), testnet4, signet
--api <url>	Custom mempool API URL (self-hosted, Umbrel)
--no-cache	Disable SQLite response caching
--no-entities	Skip entity filter loading

MCP Server (AI agents)

For structured tool calls via Model Context Protocol:

am-i-exposed mcp

Claude Desktop configuration:

{
  "mcpServers": {
    "bitcoin-privacy": {
      "command": "npx",
      "args": ["-y", "am-i-exposed", "mcp"]
    }
  }
}

Exposes 5 tools: scan_transaction, scan_address, scan_psbt, scan_wallet, compute_boltzmann. See cli/skill.md for full documentation.

Standalone binary

Build a zero-dependency binary (requires Bun):

bash scripts/build-standalone.sh
./cli/dist/am-i-exposed-linux-x64 scan tx <txid> --json

Development

pnpm install
pnpm dev          # Dev server on :3000
pnpm build        # Static export to out/
pnpm lint         # ESLint (must be 0 errors)
pnpm test         # 844+ tests (Vitest)
pnpm build:wasm   # Rebuild Boltzmann WASM from Rust source

See docs/development-guide.md for architecture, component tree, and state management details. See docs/testing-reference.md for example transactions and expected scores.

Research & Acknowledgments

The privacy engine is built on foundational research by the Bitcoin privacy community:

• LaurentMT - Creator of the Boltzmann entropy framework for Bitcoin transactions. His research series "Bitcoin Transactions & Privacy" (Parts 1-3, ~2015) defined transaction entropy E = log2(N), link probability matrices, and the mathematical tools that underpin all modern transaction privacy analysis. His Boltzmann tool was the first implementation to compute these metrics. The entropy heuristic (H5) and WASM link probability engine are direct implementations of his work.

• Greg Maxwell - Inventor of CoinJoin (2013). The original CoinJoin proposal inspired the entire ecosystem of collaborative transactions and directly motivated the entropy framework. The CIOH (H3), CoinJoin detection (H4), and entropy (H5) heuristics all trace back to concepts he introduced.

• OXT Research / ErgoBTC - "Understanding Bitcoin Privacy with OXT" 4-part series (2021). Comprehensive educational guide covering change detection, transaction graphs, wallet clustering, CIOH, and defensive measures. Directly informed heuristic implementations and user-facing explanations. Archived at: Part 1, Part 2, Part 3, Part 4.

• Kristov Atlas - CoinJoin Sudoku research, referenced by LaurentMT as foundational for deterministic link detection.

• Spiral BTC - "The Scroll #3: A Brief History of Wallet Clustering" - historical survey of chain analysis from 2011-2024, covering the evolution from naive CIOH to wallet fingerprinting with ML.

• Academic researchers: Meiklejohn et al. ("A Fistful of Bitcoins"), Moser & Narayanan ("Resurrecting Address Clustering"), Kappos et al. ("How to Peel a Million"), Reid & Harriman (2011), Ron & Shamir (2012).

• privacidadbitcoin.com - Spanish-language Bitcoin privacy education. Community entropy calculation reference that helped identify a counting error in the original implementation.

See research-boltzmann-entropy.md for the full research reference and privacy-engine.md for the technical documentation.

Support

am-i.exposed is free, open-source, and funded entirely by voluntary contributions. No ads, no subscriptions, no token.

Tip (Bitcoin, Lightning, Liquid): https://coinos.io/pay/exposed

Lightning address: exposed@coinos.io

Authors

• Copexit - Development & Architecture
• Arkad (@multicripto) - Co-author (Research & UX)

License

MIT