💰 Crypto Tax MCP — Example Conversations

A walkthrough of common workflows, showing what you say, the tool Claude calls, and the plain-language reply you get back.

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1. 📥 Import your Koinly export

You: (uploads koinly-2025.csv to Claude) "Import this — it's my Koinly export for 2025."

Claude calls:

import_transactions_csv({ source: "koinly", csv_data: "<base64>" })

Claude:

Imported 412 transactions from Koinly. Found 4 duplicates against your existing records (skipped). 3 warnings — Polygon transactions on lines 87, 142, and 301 have no fee specified; assuming $0. Ready to calculate cost basis.

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2. ✍️ Add a single transaction by hand

You: "I earned 0.05 ETH from staking on June 1, 2025. Add it as income."

Claude calls:

add_manual_transaction({ type: "earn", coin_id: "ethereum", quantity: 0.05, date: "2025-06-01" })
// price_usd omitted → auto-fetched from CoinGecko historical

Claude:

Added: 0.05 ETH earned June 1, 2025. CoinGecko historical price for that day: $3,820, so FMV = $191. That becomes ordinary income on your 2025 return, and your cost basis going forward is $3,820/ETH.

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3. 📊 Calculate gains with FIFO

You: "Run FIFO on all my 2025 sells."

Claude calls:

calculate_cost_basis({ transactions: [...all stored txs], method: "fifo", tax_year: 2025 })

Claude:

2025 FIFO results:

• Total realized gain: +$48,200
• Short-term: +$12,400 (taxed as ordinary income — ouch)
• Long-term: +$35,800 (capital gains rates)
• 87 sell transactions matched. Confidence: 96%.

⚠️ 2 missing-basis warnings — you sold 0.3 BTC from an exchange we don't have purchase records for. Want me to flag those for resolution?

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4. 🔄 Should I use LIFO or HIFO instead?

You: "What method saves the most tax?"

Claude calls:

optimize_cost_basis_method({ transactions: [...], include_methods: ["fifo", "lifo", "hifo"] })

Claude:

HIFO saves you the most. Comparison at 37% short-term / 20% long-term rates:

Method	Realized gain	Tax owed
FIFO	$48,200	$11,750
LIFO	$39,100	$9,400
HIFO	$31,800	$8,090

Switching to HIFO saves you $3,660 on this year's return. Note: the IRS allows method choice but you must apply it consistently — talk to your CPA before switching mid-stream.

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5. 🔍 Find tax-impact errors

You: "Are there any issues before I file?"

Claude calls:

detect_errors_and_explain({ transactions: [...all] })

Claude:

Found 1 error:

🚨 NEGATIVE_BALANCE: SOL on April 11, 2025 — you sold 18.4 SOL but the records only show 12.1 SOL in. You likely have a missing transfer-in from another exchange or wallet.

Fix: Import the missing 6.3 SOL purchase/transfer. Common sources: a CEX you forgot, a Phantom wallet, an airdrop, or a swap you didn't catalog. Once added, re-run calculate_cost_basis.

Confidence: 80% — bring this to 100% before filing.

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6. 🧾 Reconcile against your 1099-DA ⭐ (Tax tier)

You: "Coinbase sent me a 1099-DA showing $52,000 proceeds and $0 basis for 2025. I think it's wrong. Can you check?"

Claude calls:

compare_1099da({ exchange: "Coinbase", year: 2025, reported_proceeds_usd: 52000, reported_basis_usd: 0 })

Claude:

Coinbase's 1099-DA reports $52,000 in proceeds with $0 basis — but 38 of your Coinbase sells were assets you originally bought on Kraken ($28,400 cost basis) and moved into Coinbase before selling.

Your real gain on Coinbase 2025 activity:

• Proceeds: $52,000 ✅ (matches 1099-DA)
• Real cost basis: $36,200 (Coinbase can't see the Kraken purchases)
• Real gain: $15,800 (not $52,000)
• Discrepancy: Coinbase will report $52K to the IRS as taxable gain. You owe tax on $15.8K.

Audit risk: Medium. The IRS will see the mismatch. File Form 8949 with Box C checked (basis not reported to IRS) and attach a brief reconciliation note. We can generate that report next.

💡 This is the full Tax-tier value prop in one tool call. Plain language. Defensible numbers. Audit-ready.

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7. 📂 Browse what's stored

You: "Show me all my BTC sells in 2025."

Claude calls:

get_transactions({ year: 2025, type: "sell", coin_id: "bitcoin" })

Claude:

12 BTC sells in 2025 (total of stored: 412 transactions). Most recent first:

• 2025-12-18: −0.1 BTC @ $98,200 on Coinbase ($9,820 proceeds, fee $4.50)
• 2025-11-04: −0.05 BTC @ $76,800 on Kraken ($3,840 proceeds, fee $2.00)
• 2025-09-22: −0.2 BTC @ $58,400 on Coinbase ($11,680 proceeds, fee $5.80)
• … (showing 12 of 12; want to filter further?)

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8. 📅 Year-end summary

You: "Quick 2025 realized gains summary."

Claude calls:

get_realized_gains({ year: 2025, method: "fifo" })

Claude:

2025 realized gains (FIFO):

• Total realized gain: $48,200
• Short-term: $12,400 (87 lots) — taxed at ordinary income rates
• Long-term: $35,800 (43 lots) — taxed at LTCG rates

By coin:

Coin	Gain	Lots
BTC	+$31,200	12
ETH	+$8,400	28
SOL	+$5,100	44
LINK	+$2,800	18
DOGE	+$700	28

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9. 📤 Export Form 8949

You: "Give me a CSV my CPA can plug into TurboTax."

Claude calls:

generate_tax_report({ format: "csv", tax_year: 2025, include_audit_trail: true })

Claude:

Generated. The report has 130 line items (matching 130 sell lots). Top of file:

Coin, Buy Date, Sell Date, Quantity, Proceeds, Cost Basis, Gain/Loss, Holding Period
bitcoin, 2023-09-12, 2025-03-04, 0.08, 5760.00, 2080.00, 3680.00, long-term
bitcoin, 2023-09-12, 2025-04-15, 0.10, 7340.00, 2600.00, 4740.00, long-term
...

Audit trail attached — each line shows which buy lot was matched to which sell, using FIFO. Drop into TurboTax or send to your CPA.

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10. 🔁 Bring-your-own 1099-DA CSV

You: "I have the 1099-DA Kraken sent me as a CSV. Reconcile against my numbers."

Claude calls:

reconcile_with_1099da({ calculated_basis: <prev_result>, form_1099da_csv: "<base64>", tolerance_percent: 5 })

Claude:

Compared 23 reported lines against your calculated basis (5% tolerance):

• ✅ 19 matched within tolerance
• ⚠️ 3 mismatches — Kraken reports $0 basis where you have $1,400 / $3,200 / $890 (these were transferred in from Binance)
• 🚨 1 missing — Kraken reports a SOL sell you don't have. Did you delete a transaction by mistake?

Not ready to file until the missing tx is resolved. Want me to walk you through finding it?