Learn-skills.dev psbt

PSBT (Partially Signed Bitcoin Transaction) construction and signing — build PSBTs for ordinals purchases, estimate fees, sign with the active wallet, and broadcast finalized PSBTs.

install

source · Clone the upstream repo

git clone https://github.com/NeverSight/learn-skills.dev

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/NeverSight/learn-skills.dev "$T" && mkdir -p ~/.claude/skills && cp -r "$T/data/skills-md/aibtcdev/skills/psbt" ~/.claude/skills/neversight-learn-skills-dev-psbt && rm -rf "$T"

manifest: data/skills-md/aibtcdev/skills/psbt/SKILL.md

source content

PSBT Skill

Provides PSBT (Partially Signed Bitcoin Transaction) construction and signing operations on the Bitcoin L1. PSBTs enable multi-party signing workflows such as ordinals marketplace purchases where both buyer and seller must sign before broadcast.

estimate-fee — Read-only fee estimation for a PSBT given its structure.
sign — Sign one or more PSBT inputs with the active unlocked wallet (P2WPKH or Taproot keys).
broadcast — Finalize a fully signed PSBT and broadcast it to the Bitcoin network via mempool.space.

Usage

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

Subcommands

estimate-fee

Estimate the network fee in satoshis for a given PSBT. Parses the transaction structure and computes vsize-based fee estimate for fast, medium, and slow fee tiers.

bun run psbt/psbt.ts estimate-fee --psbt <base64>

Options:

```
--psbt <base64>
```
(required) — PSBT in base64 format

Output:

{
  "network": "mainnet",
  "vsize": 253,
  "inputsLength": 2,
  "outputsLength": 3,
  "feeEstimates": {
    "fast": { "satPerVb": 12, "totalSats": 3036 },
    "medium": { "satPerVb": 6, "totalSats": 1518 },
    "slow": { "satPerVb": 2, "totalSats": 506 }
  },
  "currentFeeSats": "1200"
}

sign

Sign PSBT inputs with the active wallet's BTC private keys (P2WPKH and/or Taproot). The wallet must be unlocked before calling this subcommand.

bun run psbt/psbt.ts sign --psbt <base64>

Options:

```
--psbt <base64>
```
(required) — PSBT in base64 format to sign
```
--inputs <indexes>
```
(optional) — Comma-separated input indexes to sign (signs all signable inputs if omitted)
```
--finalize
```
(optional) — Finalize signed inputs immediately (default: false)

Output:

{
  "success": true,
  "network": "mainnet",
  "signedInputs": [1, 2],
  "finalizedInputs": [],
  "skippedInputs": [{ "index": 0, "reason": "no matching key for this input" }],
  "psbtBase64": "<updated-base64>"
}

broadcast

Finalize a fully signed PSBT and broadcast it to the Bitcoin network via mempool.space.

bun run psbt/psbt.ts broadcast --psbt <base64>

Options:

```
--psbt <base64>
```
(required) — Fully signed PSBT in base64 format

Output:

{
  "success": true,
  "network": "mainnet",
  "txid": "abc123...",
  "explorerUrl": "https://mempool.space/tx/abc123...",
  "txHex": "0200..."
}

Notes

Wallet must be unlocked with
```
bun run wallet/wallet.ts unlock
```
before calling
```
sign
```
.
For ordinals purchase PSBTs (built by the MCP tool
```
psbt_create_ordinal_buy
```
): input index 0 is the seller's inscription UTXO; buyer inputs start at index 1. Sign only buyer inputs (index 1+) unless you are the seller.
```
broadcast
```
calls
```
tx.finalize()
```
— all inputs must be fully signed or it will throw.
Fee estimates in
```
estimate-fee
```
are based on the PSBT's current vsize; they reflect the signed transaction size, not the unsigned size.