BTC Skill

Provides Bitcoin L1 operations using mempool.space (free, no auth) and the Unisat API (for inscription/rune/cardinal UTXO classification on both mainnet and testnet). Transfer operations require an unlocked wallet. Balance and fee queries work without a wallet.

Requires UNISAT_API_KEY environment variable for UTXO classification commands.

Usage

bun run btc/btc.ts <subcommand> [options]

Subcommands

balance

Get the BTC balance for a Bitcoin address. Returns total, confirmed, and unconfirmed balances.

bun run btc/btc.ts balance [--address <addr>]

Options:

• --address (optional) — Bitcoin address to check (uses active wallet's btcAddress if omitted)

Output:

{
  "address": "bc1q...",
  "network": "mainnet",
  "balance": { "satoshis": 500000, "btc": "0.005 BTC" },
  "confirmed": { "satoshis": 500000, "btc": "0.005 BTC" },
  "unconfirmed": { "satoshis": 0, "btc": "0 BTC" },
  "utxoCount": 2,
  "explorerUrl": "https://mempool.space/address/bc1q..."
}

fees

Get current Bitcoin fee estimates for different confirmation targets.

bun run btc/btc.ts fees

Output:

{
  "network": "mainnet",
  "fees": {
    "fast": { "satPerVb": 15, "target": "~10 minutes (next block)" },
    "medium": { "satPerVb": 8, "target": "~30 minutes" },
    "slow": { "satPerVb": 3, "target": "~1 hour" }
  },
  "economy": { "satPerVb": 1, "target": "~24 hours" },
  "minimum": { "satPerVb": 1, "target": "minimum relay fee" },
  "unit": "sat/vB"
}

utxos

List all UTXOs (Unspent Transaction Outputs) for a Bitcoin address.

bun run btc/btc.ts utxos [--address <addr>] [--confirmed-only]

Options:

• --address (optional) — Bitcoin address to check (uses active wallet if omitted)
• --confirmed-only (flag) — Only return confirmed UTXOs

transfer

Transfer BTC to a recipient address. Requires an unlocked wallet with BTC balance.

By default only uses cardinal UTXOs (safe to spend — no inscriptions or runes). Set --include-ordinals to allow spending all UTXOs (advanced users only — WARNING: may destroy valuable inscriptions or runes).

bun run btc/btc.ts transfer --recipient <addr> --amount <satoshis> [--fee-rate fast|medium|slow|<number>] [--include-ordinals]

Options:

• --recipient (required) — Bitcoin address to send to
• --amount (required) — Amount in satoshis (1 BTC = 100,000,000 satoshis)
• --fee-rate (optional) — fast, medium, slow, or a number in sat/vB (default: medium)
• --include-ordinals (flag) — Include all UTXOs (WARNING: may destroy inscriptions or runes!)

get-cardinal-utxos

Get cardinal UTXOs (safe to spend — no inscriptions or runes).

bun run btc/btc.ts get-cardinal-utxos [--address <addr>] [--confirmed-only]

Options:

• --address (optional) — Bitcoin address to check (uses active wallet if omitted)
• --confirmed-only (flag) — Only return confirmed UTXOs

get-ordinal-utxos

Get ordinal UTXOs (contain inscriptions — do not spend in regular transfers).

bun run btc/btc.ts get-ordinal-utxos [--address <addr>] [--confirmed-only]

Options:

• --address (optional) — Bitcoin address to check (uses active wallet if omitted)
• --confirmed-only (flag) — Only return confirmed UTXOs

get-rune-utxos

Get rune UTXOs (contain rune balances — do not spend in regular transfers).

bun run btc/btc.ts get-rune-utxos [--address <addr>] [--confirmed-only]

Options:

• --address (optional) — Bitcoin address to check (uses active wallet if omitted)
• --confirmed-only (flag) — Only return confirmed UTXOs

get-inscriptions

Get all inscriptions owned by a Bitcoin address via the Unisat API.

bun run btc/btc.ts get-inscriptions [--address <addr>]

Options:

• --address (optional) — Bitcoin address to check (uses active wallet if omitted)

Output:

{
  "address": "bc1q...",
  "network": "mainnet",
  "inscriptions": [
    {
      "id": "abc123...i0",
      "number": 12345,
      "contentType": "text/plain",
      "contentLength": 42,
      "output": "abc123...:0",
      "location": "abc123...:0:0",
      "offset": 0,
      "outputValue": 546,
      "genesis": {
        "txid": "abc123...",
        "timestamp": "2024-01-01T00:00:00.000Z"
      }
    }
  ],
  "summary": { "count": 1, "contentTypes": ["text/plain"] },
  "explorerUrl": "https://mempool.space/address/bc1q..."
}

Notes

• All fee queries use the public mempool.space API (no authentication required)
• UTXO classification (cardinal/ordinal/rune) uses the Unisat API and works on both mainnet and testnet
• transfer is safe by default — it skips UTXOs that contain inscriptions or runes
• Wallet operations require an unlocked wallet (use bun run wallet/wallet.ts unlock first)
• Set UNISAT_API_KEY environment variable for Unisat API access