Moltline TaxLots

Crypto cost-basis lots (FIFO/LIFO/HIFO/specific-ID), Form 8949 rows, 1099-DA diff.

CommunityDegradedNo sign-inGlobalFreeRead-only

What it can do

    What data it sees

    Do you need an account

    No: the server works without sign-in

    Crypto cost-basis lots (FIFO/LIFO/HIFO/specific-ID), Form 8949 rows, 1099-DA diff. 5 of 8 free.

    How to connect

    How to connect Moltline TaxLots to Claude

    The server address to paste into Claude settings:

    https://mcp.moltlinestudio.com/taxlots

    1. Open Claude (claude.ai or the desktop app).
    2. Go to Settings → Connectors.
    3. Click Add custom connector.
    4. Paste the server address copied below into Remote MCP server URL and click Add.
    5. In a chat, click + → Connectors and switch the new connector on.

    Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

    Authorization

    After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

    How to connect Moltline TaxLots to ChatGPT

    The server address to paste into ChatGPT settings:

    https://mcp.moltlinestudio.com/taxlots

    1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
    2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
    3. Open Settings → Connectors and click Create.
    4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
    5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
    6. In a new chat open + → Apps/Connectors and enable the connector.

    OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

    Authorization

    On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

    How to connect Moltline TaxLots to Cursor

    The server address to paste into Cursor settings:

    https://mcp.moltlinestudio.com/taxlots

    Fastest: click Open in Cursor below and confirm the prompt.

    Manually:

    1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
    2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
    3. Save the file. The server appears in the MCP list; authorize it there if asked.

    Authorization

    If the service needs sign-in, an authorize button appears next to the server in the MCP list.

    Server tool list (8)

    Raw names from tools/list. Only developers need these.

    parse_transactionsNormalise an exchange CSV export into the canonical ledger rows. FREE. Supports the Coinbase transaction-history export (Transaction Type / Asset / Quantity Transacted columns), the Kraken ledgers export (txid / refid / type / asset / amount / fee) and a generic CSV with the canonical columns ts, type, asset, qty, fiat_value, fee_qty, fee_asset, fee_fiat, counter_asset, counter_qty, account, id. Typical input {"csv_text": "...", "source_hint": "coinbase"} returns {"rows": [...], "detected": "coinbase", "unrecognised": [...], "warnings": [...]}. Rows it cannot read are returned under unrecognised with the reason, never dropped silently. In every row qty is the whole amount that entered or left the account; when a fee was paid in the same asset, fee_qty is the part of qty that was the fee. Use before ledger_lint and build_lots. Not for other exchanges: convert those to the generic columns first. Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"} (for example {"error": "csv_text must be the CSV file contents"}). Every call is read-only and idempotent, so after correcting the input it is always safe to retry.
    ledger_lintFind the problems that break a lot build: missing values, duplicates, negative balances. FREE. Typical input {"ledger": <rows from parse_transactions>} returns {"issues": [{"severity": "error", "row": "cb12", "issue": "sell of 0.5 BTC exceeds balance 0.2 in account coinbase"}], "balances": {"coinbase": {"BTC": "0.2"}}, "counts": {...}}. Balances are running quantities per account and asset in time order, ignoring transfers' fiat values. Use after parse_transactions and before build_lots. Not a tax check: it checks the ledger's arithmetic consistency only. Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"}. Every call is read-only and idempotent, so after correcting the input it is always safe to retry.
    match_transfersPair withdrawals with the deposits that received them between your own accounts. FREE. Typical input {"ledger": <rows>, "window_minutes": 1440} returns {"pairs": [{"out": "kr91", "in": "cb14", "asset": "BTC", "from": "kraken", "to": "coinbase", "network_fee": "0.0001", "minutes": 42.0}], "unmatched": {"transfer_out": [...], "transfer_in": [...]}}. A pair needs the same asset, a different account, the deposit inside the window after the withdrawal, and a quantity within tolerance_pct of the amount sent net of the fee. Use before build_lots so basis and holding period move with the coins instead of being treated as a sale. Not for transfers to third parties: those stay unmatched and should be typed gift_out or sell. Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"}. Every call is read-only and idempotent, so after correcting the input it is always safe to retry.
    build_lotsBuild the lot inventory per account and every disposal with basis, gain and holding period. PREMIUM (license). Methods: fifo (the default rule when no specific identification is made, Treas. Reg. 1.1012-1(j)), lifo, hifo, or specific_id via a row's specific_lots {lot_id: qty}. Typical input {"ledger": <rows>, "method": "hifo", "transfers": <pairs from match_transfers>} returns {"disposals": [{"row": "cb9", "asset": "BTC", "qty": "0.5", "proceeds": "31000.00", "basis": "20000.00", "gain": "11000.00", "term": "long", ...}], "open_lots": [...], "summary": {"short_term": {...}, "long_term": {...}}}. Fees: a cash purchase's fee joins basis; a sale's or exchange's fee reduces the amount realized (1.1001-7); a network fee paid in the transferred asset is a disposal of those units (transfer_fee_policy dispose) unless you choose ignore. Transfers between your own accounts move lots with their basis and acquisition date. Use once ledger_lint reports no errors. Not tax advice: it applies the stated rules to your rows and shows its work. Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"} (for example {"error": "method must be fifo, lifo, hifo or specific_id"}). Every call is read-only and idempotent, so after correcting the input it is always safe to retry.
    form_8949_rowsLay the disposals out as Form 8949 rows with box categories and totals. PREMIUM (license). Typical input {"disposals": <from build_lots>, "tax_year": 2026, "default_reporting": "proceeds_only"} returns {"part_i": {"B": [rows]}, "part_ii": {"E": [rows]}, "totals": {...}}. Columns follow the form: description (a), date acquired (b), date sold (c), proceeds (d), cost or other basis (e), code (f), adjustment (g), gain or loss (h). Box: A/D when the broker reported proceeds and basis, B/E when proceeds only, C/F when no broker form - set per row in reporting {row_id: value} or for all rows with default_reporting. Use to draft the schedule from computed disposals. Not a filing: check the current form instructions. Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"} (for example {"error": "disposals must be a non-empty list from build_lots"}). Every call is read-only and idempotent, so after correcting the input it is always safe to retry.
    reconcile_1099daDiff the broker's 1099-DA lines against the computed disposals. PREMIUM (license). Typical input {"disposals": <from build_lots>, "form_rows": [{"asset": "BTC", "date_sold": "2026-03-04", "qty": "0.5", "proceeds": "31000", "basis": "", "account": "coinbase"}]} returns {"matched": [...], "broker_missing_basis": [...], "basis_mismatch": [...], "proceeds_mismatch": [...], "unmatched_form_rows": [...], "unmatched_disposals": [...]}. A line matches a disposal on the same account (when given), asset and sale date with quantity and proceeds inside the tolerances; several lots sold in one order are summed first. Use when the form arrives and the basis column is blank for coins that came from your own wallet. Not a substitute for the broker's statement. Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"} (for example {"error": "disposals must be a non-empty list from build_lots"}). Every call is read-only and idempotent, so after correcting the input it is always safe to retry.
    wash_window_checkFlag loss disposals with a repurchase of the same asset inside the window. FREE. Typical input {"disposals": <from build_lots>, "acquisitions": [{"asset": "ETH", "ts": "2026-02-10T10:00:00Z", "qty": "2"}]} returns {"flags": [{"row": "cb7", "asset": "ETH", "loss": "-410.00", "repurchases": [...]}], "rule_status": "..."}. The 30-day window before and after the sale is the one IRC 1091 uses for stock or securities; as checked on the verification date that statute had not been extended to digital assets that are not securities, so the output is a heads-up for planning, not an adjustment. Use when reviewing loss harvesting. Not a determination that any rule applies. Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"} (for example {"error": "disposals and acquisitions must be lists"}). Every call is read-only and idempotent, so after correcting the input it is always safe to retry.
    lp_position_mathImpermanent loss, hold-vs-pool value and basis split for a two-asset constant-product pool. FREE. Typical input {"deposit": {"asset_a": "ETH", "qty_a": "1", "price_a": "2000", "asset_b": "USDC", "qty_b": "2000", "price_b": "1"}, "current_prices": {"ETH": "3000", "USDC": "1"}} returns {"il_pct": "-2.02", "hold_value": "5000.00", "pool_value": "4898.98", "deposit_value": "4000.00", "basis_split": {...}}. The pool value assumes x*y=k with no fees; add fees_earned_fiat to see the net. The basis split is the deposit's fiat value at deposit, allocated by each side's share, which is the arithmetic a lot engine needs if the LP position is treated as one asset. Use for DeFi position reviews. Not a determination of whether the deposit is a taxable exchange. Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"} (for example {"error": "deposit and current_prices must be objects"}). Every call is read-only and idempotent, so after correcting the input it is always safe to retry.