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

# SignTransaction

> Add cryptographic signatures to a compiled transaction.

Adds one or more Ed25519 signatures to a compiled transaction. Supply either private keys directly or seed+passphrase pairs — never both.

**State transitions:** COMPILED + all required signers → FULLY\_SIGNED. COMPILED + subset of signers → PARTIALLY\_SIGNED. PARTIALLY\_SIGNED + remaining signers → FULLY\_SIGNED. See [Transaction Lifecycle](/concepts/transaction-lifecycle) for the full state machine.

<Warning>
  Private keys are transmitted in plaintext over the gRPC connection. Always use TLS in production.
  Never call this method over an unencrypted connection with real private keys.
</Warning>

## Request

<ResponseField name="transaction" type="Transaction (object)" required>
  Transaction to sign. Must be in COMPILED or PARTIALLY\_SIGNED state.
</ResponseField>

<Note>
  Supply either `private_keys` or `seeds` — never both. These are mutually exclusive signing methods.
</Note>

<ResponseField name="private_keys" type="SignWithPrivateKeys (object) — one of">
  Sign using raw private keys.

  <Expandable title="SignWithPrivateKeys fields">
    <ResponseField name="private_keys" type="string[]">
      List of Base58-encoded Ed25519 private keys.
    </ResponseField>
  </Expandable>
</ResponseField>

<ResponseField name="seeds" type="SignWithSeeds (object) — one of">
  Sign using seed+passphrase pairs for key derivation.

  <Expandable title="SignWithSeeds fields">
    <ResponseField name="seeds" type="KeySeed[]">
      List of seed+passphrase pairs.

      <Expandable title="KeySeed fields">
        <ResponseField name="seed" type="string">
          Hex-encoded seed.
        </ResponseField>

        <ResponseField name="passphrase" type="string">
          Optional passphrase for key derivation.
        </ResponseField>
      </Expandable>
    </ResponseField>
  </Expandable>
</ResponseField>

## Response

<ResponseField name="transaction" type="Transaction (object)">
  Transaction with added signatures. State is PARTIALLY\_SIGNED or FULLY\_SIGNED depending on how many required signers have signed.

  <Expandable title="Transaction fields">
    <ResponseField name="state" type="TransactionState enum">
      TRANSACTION\_STATE\_PARTIALLY\_SIGNED (3) or TRANSACTION\_STATE\_FULLY\_SIGNED (4).
    </ResponseField>

    <ResponseField name="signatures" type="string[]">
      All signatures collected so far, as Base58-encoded strings.
    </ResponseField>
  </Expandable>
</ResponseField>

## Code Examples

<CodeGroup>
  ```go Go theme={null}
  // Sign with private keys
  resp, err := client.SignTransaction(ctx, &transaction_v1.SignTransactionRequest{
      Transaction: compiledTxn,
      SigningMethod: &transaction_v1.SignTransactionRequest_PrivateKeys{
          PrivateKeys: &transaction_v1.SignWithPrivateKeys{
              PrivateKeys: []string{"YourBase58PrivateKey111111111111111111111111111"},
          },
      },
  })
  if err != nil {
      log.Fatal(err)
  }
  fmt.Printf("State: %v\n", resp.Transaction.State)
  ```

  ```rust Rust theme={null}
  use transaction_v1::sign_transaction_request::SigningMethod;

  let response = client.sign_transaction(tonic::Request::new(SignTransactionRequest {
      transaction: Some(compiled_txn),
      signing_method: Some(SigningMethod::PrivateKeys(SignWithPrivateKeys {
          private_keys: vec!["YourBase58PrivateKey111111111111111111111111111".to_string()],
      })),
  })).await?;
  let signed = response.into_inner().transaction.unwrap();
  println!("State: {:?}", signed.state);
  ```

  ```typescript TypeScript theme={null}
  const req = new SignTransactionRequest();
  req.setTransaction(compiledTxn);
  const privateKeys = new SignWithPrivateKeys();
  privateKeys.setPrivateKeysList(["YourBase58PrivateKey111111111111111111111111111"]);
  req.setPrivateKeys(privateKeys);
  client.signTransaction(req, (err, response) => {
    const signed = response.getTransaction();
    console.log("State:", signed.getState());
  });
  ```
</CodeGroup>