> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/bitcoin/bitcoin/llms.txt
> Use this file to discover all available pages before exploring further.

# Partially Signed Bitcoin Transactions (PSBT)

> Understanding and working with PSBTs in Bitcoin Core for collaborative transaction signing

Partially Signed Bitcoin Transactions (PSBT) is an interchange format for Bitcoin transactions that are not fully signed yet, together with relevant metadata to help entities work towards signing it.

PSBT was introduced in [BIP 174](https://github.com/bitcoin/bips/blob/master/bip-0174.mediawiki) and has been supported in Bitcoin Core since version 0.17.

## What is PSBT?

PSBT simplifies workflows where multiple parties need to cooperate to produce a transaction. Common use cases include:

* Hardware wallets
* Multi-signature setups
* Offline signing
* CoinJoin transactions

## PSBT Workflow

The PSBT process involves several distinct roles:

<Steps>
  <Step title="Creator">
    Proposes a transaction by constructing a PSBT with specific inputs and outputs, but no additional metadata.

    ```bash theme={null}
    bitcoin-cli createpsbt \
      '[{"txid":"txid_here","vout":0}]' \
      '{"receiving_address":0.01}'
    ```
  </Step>

  <Step title="Updater">
    Adds information about the UTXOs being spent and scripts/public keys involved:

    ```bash theme={null}
    bitcoin-cli utxoupdatepsbt "psbt_base64"
    ```
  </Step>

  <Step title="Signer">
    Inspects the transaction and produces partial signatures for inputs they control:

    ```bash theme={null}
    bitcoin-cli walletprocesspsbt "psbt_base64"
    ```
  </Step>

  <Step title="Combiner (if needed)">
    Merges metadata from different PSBTs for the same transaction:

    ```bash theme={null}
    bitcoin-cli combinepsbt '["psbt1_base64", "psbt2_base64"]'
    ```
  </Step>

  <Step title="Finalizer">
    Converts partial signatures into final scriptSig and scriptWitness:

    ```bash theme={null}
    bitcoin-cli finalizepsbt "psbt_base64"
    ```
  </Step>

  <Step title="Extractor">
    Produces a valid network-format Bitcoin transaction:

    The `finalizepsbt` command outputs the final transaction hex if all inputs are signed.
  </Step>
</Steps>

## Bitcoin Core PSBT RPCs

### Creating PSBTs

**createpsbt** - Create a PSBT from inputs and outputs:

```bash theme={null}
bitcoin-cli createpsbt \
  '[{"txid":"abc...","vout":0}]' \
  '{"tb1q...": 0.01}'
```

**walletcreatefundedpsbt** - Create and fund a PSBT automatically:

```bash theme={null}
bitcoin-cli walletcreatefundedpsbt \
  '[]' \
  '{"destination_address": 0.01}'
```

This command acts as Creator and Updater, adding inputs, change, and metadata.

**converttopsbt** - Convert unsigned raw transaction to PSBT:

```bash theme={null}
bitcoin-cli converttopsbt "raw_transaction_hex"
```

### Processing PSBTs

**walletprocesspsbt** - Add UTXO/key/script data and sign:

```bash theme={null}
bitcoin-cli -rpcwallet="mywallet" walletprocesspsbt \
  "psbt_base64" \
  true  # sign if possible
```

**descriptorprocesspsbt** - Sign using specific descriptors:

```bash theme={null}
bitcoin-cli descriptorprocesspsbt \
  "psbt_base64" \
  '["wpkh(...)#checksum"]'
```

**utxoupdatepsbt** - Add UTXO information from the UTXO set:

```bash theme={null}
bitcoin-cli utxoupdatepsbt "psbt_base64"
```

<Note>
  `utxoupdatepsbt` only works for SegWit inputs where UTXO data is available.
</Note>

### Analyzing PSBTs

**decodepsbt** - Display PSBT in human-readable JSON format:

```bash theme={null}
bitcoin-cli decodepsbt "psbt_base64"
```

**analyzepsbt** - Examine current status and next steps:

```bash theme={null}
bitcoin-cli analyzepsbt "psbt_base64"
```

Returns information about:

* Missing signatures
* Next required role
* Estimated fee and weight
* Input status

### Combining PSBTs

**combinepsbt** - Merge multiple versions of the same PSBT:

```bash theme={null}
bitcoin-cli combinepsbt '["psbt1", "psbt2"]'
```

Use this when multiple signers independently sign the same PSBT.

**joinpsbts** - Concatenate inputs and outputs from multiple PSBTs:

```bash theme={null}
bitcoin-cli joinpsbts '["psbt1", "psbt2"]'
```

<Warning>
  `joinpsbts` is for CoinJoin-style transactions where PSBTs have different inputs/outputs. For multi-signature workflows, use `combinepsbt` instead.
</Warning>

### Finalizing PSBTs

**finalizepsbt** - Finalize and extract the transaction:

```bash theme={null}
bitcoin-cli finalizepsbt "psbt_base64"
```

Returns:

* `hex` - Final transaction hex (if complete)
* `complete` - Boolean indicating if all inputs are signed

## Complete PSBT Example

Here's a full workflow creating and signing a PSBT:

<Steps>
  <Step title="Create and fund PSBT">
    ```bash theme={null}
    PSBT=$(bitcoin-cli walletcreatefundedpsbt \
      '[]' \
      '{"tb1qxxx...": 0.01}' \
      | jq -r '.psbt')
    ```
  </Step>

  <Step title="Analyze the PSBT">
    ```bash theme={null}
    bitcoin-cli analyzepsbt "$PSBT"
    ```
  </Step>

  <Step title="Sign with wallet">
    ```bash theme={null}
    SIGNED=$(bitcoin-cli walletprocesspsbt "$PSBT" \
      | jq -r '.psbt')
    ```
  </Step>

  <Step title="Finalize and broadcast">
    ```bash theme={null}
    HEX=$(bitcoin-cli finalizepsbt "$SIGNED" | jq -r '.hex')
    bitcoin-cli sendrawtransaction "$HEX"
    ```
  </Step>
</Steps>

## PSBT for Offline Signing

PSBTs are essential for offline signing workflows:

1. **Online wallet** creates unsigned PSBT
2. Transfer PSBT to **offline wallet** (via USB, QR code, etc.)
3. **Offline wallet** signs the PSBT
4. Transfer signed PSBT back to **online wallet**
5. **Online wallet** broadcasts the transaction

See the [Offline Signing guide](/transactions/offline-signing) for detailed instructions.

## Security Considerations

<Warning>
  Always verify PSBT contents before signing:

  * Check all output addresses
  * Verify amounts and fees
  * Ensure inputs belong to your wallet
  * Use `decodepsbt` and `analyzepsbt` to inspect details
</Warning>

## Advanced Features

### Custom Signing

Sign only specific inputs:

```bash theme={null}
bitcoin-cli walletprocesspsbt "$PSBT" true "ALL" 0
```

The last parameter specifies which input to sign.

### Sighash Types

Specify different signature hash types:

```bash theme={null}
bitcoin-cli walletprocesspsbt "$PSBT" true "ALL|ANYONECANPAY"
```

Available sighash types:

* `ALL` (default)
* `NONE`
* `SINGLE`
* `ALL|ANYONECANPAY`

## Next Steps

<CardGroup cols={2}>
  <Card title="Multi-signature" icon="users" href="/transactions/multisig">
    Use PSBTs for multi-signature transactions
  </Card>

  <Card title="Offline Signing" icon="shield" href="/transactions/offline-signing">
    Sign transactions on an air-gapped machine
  </Card>
</CardGroup>