# Btc

> Bitcoin L1 operations — check balances, estimate fees, list UTXOs, transfer BTC, and classify UTXOs as cardinal (safe to spend), ordinal (inscriptions), or rune (rune tokens). Data sourced from mempool.space and the Unisat API.

- Skill: `aibtcdev/btc` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add aibtcdev/btc`
- Raw SKILL.md: https://api.skillmd.com/api/skills/aibtcdev/btc/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Integrations & APIs
- Author: aibtcdev (https://skillmd.com/u/aibtcdev)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/aibtcdev/btc

---


# 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:
```json
{
  "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:
```json
{
  "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:
```json
{
  "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