> ## Documentation Index
> Fetch the complete documentation index at: https://turnkey-0e7c1f5b-omkar-spark-phase2-docs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Spark prepare transfer

> Atomically compute key tweaks, Feldman-split them for Spark Operators, encrypt the receiver's new leaf key, and sign the transfer payload — all inside the Turnkey enclave.

export const EndpointPath = ({type, path}) => {
  return <div class="flex w-full flex-col bg-background-light dark:bg-background-dark border-standard rounded-2xl p-1.5">
      <div class="flex items-center space-x-1.5">
        <div class="relative flex-1 flex gap-2 min-w-0 rounded-xl items-center cursor-pointer p-1.5 border-standard">
          <div class="rounded-lg font-bold px-1.5 py-0.5 text-sm leading-5 bg-blue-400/20 dark:bg-blue-400/20 text-blue-700 dark:text-blue-400">
            POST
          </div>
          <div class="flex items-center space-x-2 overflow-x-auto flex-1 no-scrollbar">
            <div class="group flex items-center flex-1 gap-0.5 font-mono">
              <div class="absolute right-0 p-2 bg-background-light dark:bg-background-dark rounded-lg hidden group-hover:block">
                <svg class="w-4 h-4 bg-gray-400 dark:bg-white/30"></svg>
              </div>
              <div class="text-sm text-gray-400">/</div>
              <div class="text-sm font-medium text-gray-800 dark:text-white min-w-max">
                public
              </div>
              <div class="text-sm text-gray-400">/</div>
              <div class="text-sm font-medium text-gray-800 dark:text-white min-w-max">
                v1
              </div>
              <div class="text-sm text-gray-400">/</div>
              <div class="text-sm font-medium text-gray-800 dark:text-white min-w-max">
                {type}
              </div>
              <div class="text-sm text-gray-400">/</div>
              <div class="text-sm font-medium text-gray-800 dark:text-white min-w-max">
                {path}
              </div>
            </div>
          </div>
        </div>
      </div>
    </div>;
};

export const NestedParam = ({parentKey, childKey, type, required, description, children}) => {
  const fullKey = `${parentKey}.${childKey}`;
  const anchorId = `body-${fullKey.replace(/\./g, '-')}`;
  return <div className="py-6 border-gray-100 dark:border-gray-800 border-b last:border-b-0">
  <div className="flex font-mono text-sm group/param-head param-head break-all relative" id={anchorId}>
    <div className="flex-1 flex content-start py-0.5 mr-5">
      <div className="flex items-center flex-wrap gap-2">
        <div className="absolute -top-1.5">
          <a href={`#${anchorId}`} className="-ml-[2.1rem] flex items-center opacity-0 border-0 group-hover/param-head:opacity-100 py-2 [.expandable-content_&]:-ml-[2.1rem]" aria-label="Navigate to header">
            <div className="w-6 h-6 text-gray-400 rounded-md flex items-center justify-center zinc-box bg-white ring-1 ring-gray-400/30 dark:ring-gray-700/25 hover:ring-gray-400/60 dark:hover:ring-white/20">
              <svg xmlns="http://www.w3.org/2000/svg" fill="gray" height="12px" viewBox="0 0 576 512">
                <path d="M0 256C0 167.6 71.6 96 160 96h72c13.3 0 24 10.7 24 24s-10.7 24-24 24H160C98.1 144 48 194.1 48 256s50.1 112 112 112h72c13.3 0 24 10.7 24 24s-10.7 24-24 24H160C71.6 416 0 344.4 0 256zm576 0c0 88.4-71.6 160-160 160H344c-13.3 0-24-10.7-24-24s10.7-24 24-24h72c61.9 0 112-50.1 112-112s-50.1-112-112-112H344c-13.3 0-24-10.7-24-24s10.7-24 24-24h72c88.4 0 160 71.6 160 160zM184 232H392c13.3 0 24 10.7 24 24s-10.7 24-24 24H184c-13.3 0-24-10.7-24-24s10.7-24 24-24z"></path>
              </svg>
            </div>
          </a>
        </div>
        <div className="font-semibold text-primary dark:text-primary-light cursor-pointer overflow-wrap-anywhere">
          <span className="text-gray-500 dark:text-gray-400">{parentKey}.</span>
          {childKey}
        </div>
        <div className="inline items-center gap-2 text-xs font-medium [&_div]:inline [&_div]:mr-2 [&_div]:leading-5">
          <div className="flex items-center px-2 py-0.5 rounded-md bg-gray-100/50 dark:bg-white/5 text-gray-600 dark:text-gray-200 font-medium break-all">
            <span>{type}</span>
          </div>
          {required && <span className="px-2 py-0.5 rounded-md bg-red-100/50 dark:bg-red-400/10 text-red-600 dark:text-red-300 font-medium whitespace-nowrap">
              required
            </span>}
        </div>
      </div>
    </div>
  </div>
  {children && <div className="mt-4">
      <div className="prose prose-sm prose-gray dark:prose-invert">
        {children}
      </div>
    </div>}
</div>;
};

export const H3Bordered = ({text}) => <h3 id={text.toLowerCase()} className="border-b pb-2.5 border-gray-100 dark:border-gray-800">
    {text}
  </h3>;

export const Authorizations = () => {
  return <div>
      <H3Bordered text="Authorizations" />

      <Tabs>
        <Tab title="API Key">
          <div className="flex text-sm group/param-head param-head break-all relative" id="authorization-x-stamp">
            <ParamField header="X-Stamp" type="string" required={true}>
              Cryptographically signed (stamped) request to be passed in as a header. For more info, see <a href="https://docs.turnkey.com/developer-reference/api-overview/stamps">here</a>.
            </ParamField>
          </div>
        </Tab>

        <Tab title="WebAuthn (Passkey)">
         <div className="flex text-sm group/param-head param-head break-all relative" id="authorization-x-stamp-webauthn">
            <ParamField body="X-Stamp-WebAuthn" type="string" required={true}>
              Cryptographically signed (stamped) request to be passed in as a header. For more info, see <a href="https://docs.turnkey.com/developer-reference/api-overview/stamps">here</a>.
            </ParamField>
          </div>
        </Tab>
      </Tabs>
    </div>;
};

<EndpointPath type="submit" path="spark_prepare_transfer" />

<Authorizations />

<H3Bordered text="Body" />

<ParamField body="type" type="enum<string>" required={true}>
  Enum options: `ACTIVITY_TYPE_SPARK_PREPARE_TRANSFER`
</ParamField>

<ParamField body="timestampMs" type="string" required={true}>
  Timestamp (in milliseconds) of the request, used to verify liveness of user requests.
</ParamField>

<ParamField body="organizationId" type="string" required={true}>
  Unique identifier for a given Organization.
</ParamField>

<ParamField body="parameters" type="object" required={true} path="parameters">
  <p>The parameters object containing the specific intent data for this activity.</p>

  <Expandable title="details">
    <NestedParam parentKey="parameters" childKey="signWith" type="string" required={true} default="">
      The Spark address of the sender's signing identity. Determines which enclave-held identity key is used to derive leaf keys and sign the transfer payload.
    </NestedParam>

    <ParamField body="transfer" type="object" required={true} path="parameters.transfer">
      <p>The complete transfer descriptor including the receiver, Spark Operators, and all leaves being transferred.</p>

      <Expandable title="transfer details">
        <NestedParam parentKey="parameters.transfer" childKey="transferId" type="string" required={true} default="">
          A UUID v7 that uniquely identifies this transfer. Used by the enclave and Spark Operators to correlate all messages in the transfer flow.
        </NestedParam>

        <NestedParam parentKey="parameters.transfer" childKey="threshold" type="number" required={true} default="">
          The Shamir secret sharing threshold — the minimum number of Spark Operators that must cooperate to reconstruct any key tweak share. Must be ≤ the number of `operatorRecipients`.
        </NestedParam>

        <NestedParam parentKey="parameters.transfer" childKey="receiverPublicKey" type="string" required={true} default="">
          The receiver's Spark identity public key, hex-encoded (compressed secp256k1). The enclave ECIES-encrypts the receiver's new leaf private key to this public key so only the receiver can decrypt it during the claim step.
        </NestedParam>

        <ParamField body="operatorRecipients" type="array" required={true} path="parameters.transfer.operatorRecipients">
          <p>The list of Spark Operators that will receive encrypted key tweak shares. Each operator's Shamir share is ECIES-encrypted to its individual encryption public key.</p>

          <Expandable title="item details">
            <NestedParam parentKey="parameters.transfer.operatorRecipients" childKey="operatorId" type="string" required={true} default="">
              The Spark Operator identifier (e.g. `"SO1"`).
            </NestedParam>

            <NestedParam parentKey="parameters.transfer.operatorRecipients" childKey="encryptionPublicKey" type="string" required={true} default="">
              The operator's ECIES encryption public key, hex-encoded. The enclave uses this key to encrypt the operator's Shamir share so only that operator can decrypt it.
            </NestedParam>
          </Expandable>
        </ParamField>

        <ParamField body="leaves" type="array" required={true} path="parameters.transfer.leaves">
          <p>The list of Spark leaves being transferred. Each entry specifies the old leaf key, the new leaf key, and the pre-aggregated refund signatures that were produced in the preceding `SPARK_SIGN_FROST` call.</p>

          <Expandable title="item details">
            <NestedParam parentKey="parameters.transfer.leaves" childKey="leafId" type="string" required={true} default="">
              The identifier of the leaf being transferred.
            </NestedParam>

            <NestedParam parentKey="parameters.transfer.leaves" childKey="oldLeafDerivation" type="object" required={true} default="">
              Derivation descriptor for the sender's current leaf key. Must use `signingLeaf` with the current leaf's `leafId` — e.g. `{ "signingLeaf": { "leafId": "<old-leaf-id>" } }`. The enclave derives the current leaf private key to compute the tweak.
            </NestedParam>

            <NestedParam parentKey="parameters.transfer.leaves" childKey="newLeafDerivation" type="object" required={true} default="">
              Derivation descriptor for the receiver's new leaf key. Must use `signingLeaf` with the new leaf's `leafId` — e.g. `{ "signingLeaf": { "leafId": "<new-leaf-id>" } }`. The enclave derives this key and encrypts it to the receiver's identity public key.
            </NestedParam>

            <NestedParam parentKey="parameters.transfer.leaves" childKey="refundSignature" type="string" required={true} default="">
              The fully aggregated Schnorr signature for the new leaf's CPFP refund transaction, hex-encoded. Produced by aggregating the partial signatures from `SPARK_SIGN_FROST` with the Spark Operators' shares.
            </NestedParam>

            <NestedParam parentKey="parameters.transfer.leaves" childKey="directRefundSignature" type="string" required={true} default="">
              The fully aggregated Schnorr signature for the new leaf's direct refund transaction, hex-encoded.
            </NestedParam>

            <NestedParam parentKey="parameters.transfer.leaves" childKey="directFromCpfpRefundSignature" type="string" required={true} default="">
              The fully aggregated Schnorr signature for the new leaf's direct-from-CPFP refund transaction, hex-encoded.
            </NestedParam>
          </Expandable>
        </ParamField>
      </Expandable>
    </ParamField>
  </Expandable>
</ParamField>

<ParamField body="generateAppProofs" type="boolean" required={false}>
  Enable to have your activity generate and return App Proofs, enabling verifiability.
</ParamField>

<H3Bordered text="Response" />

A successful response returns the following fields:

<ResponseField name="activity" type="object" required={true}>
  The activity object containing type, intent, and result

  <Expandable title="activity details">
    <NestedParam parentKey="activity" childKey="id" type="string" required={true}>
      Unique identifier for a given Activity object.
    </NestedParam>

    <NestedParam parentKey="activity" childKey="organizationId" type="string" required={true}>
      Unique identifier for a given Organization.
    </NestedParam>

    <NestedParam parentKey="activity" childKey="status" type="string" required={true}>
      The activity status
    </NestedParam>

    <NestedParam parentKey="activity" childKey="type" type="string" required={true}>
      The activity type
    </NestedParam>

    <NestedParam parentKey="activity" childKey="intent" type="object" required={true}>
      The intent of the activity

      <Expandable title="intent details">
        <NestedParam parentKey="activity.intent" childKey="prepareSparkTransferIntent" type="object" required={true}>
          The prepareSparkTransferIntent object

          <Expandable title="prepareSparkTransferIntent details">
            <NestedParam parentKey="activity.intent.prepareSparkTransferIntent" childKey="signWith" type="string" required={true}>
              The Spark address of the sender's signing identity.
            </NestedParam>

            <NestedParam parentKey="activity.intent.prepareSparkTransferIntent" childKey="transfer" type="object" required={true}>
              The transfer descriptor submitted.
            </NestedParam>
          </Expandable>
        </NestedParam>
      </Expandable>
    </NestedParam>

    <NestedParam parentKey="activity" childKey="result" type="object" required={true}>
      The result of the activity

      <Expandable title="result details">
        <NestedParam parentKey="activity.result" childKey="prepareSparkTransferResult" type="object" required={true}>
          The prepareSparkTransferResult object

          <Expandable title="prepareSparkTransferResult details">
            <NestedParam parentKey="activity.result.prepareSparkTransferResult" childKey="operatorPackages" type="array" required={true}>
              One encrypted package per Spark Operator. Each package contains that operator's Feldman-split key tweak share, ECIES-encrypted to the operator's encryption public key. Send each package to its corresponding operator.

              <Expandable title="operatorPackages details">
                <NestedParam parentKey="activity.result.prepareSparkTransferResult.operatorPackages" childKey="operatorId" type="string" required={true}>
                  The Spark Operator identifier this package is addressed to.
                </NestedParam>

                <NestedParam parentKey="activity.result.prepareSparkTransferResult.operatorPackages" childKey="encryptedPackage" type="string" required={true}>
                  The ECIES-encrypted key tweak share for this operator, hex-encoded.
                </NestedParam>
              </Expandable>
            </NestedParam>

            <NestedParam parentKey="activity.result.prepareSparkTransferResult" childKey="transferUserSignature" type="string" required={true}>
              The sender's ECDSA signature over the transfer payload (DER-encoded, hex), produced with the sender's Spark identity key inside the enclave. Spark Operators use this signature to verify that the transfer was authorized by the legitimate key holder.
            </NestedParam>
          </Expandable>
        </NestedParam>
      </Expandable>
    </NestedParam>

    <NestedParam parentKey="activity" childKey="votes" type="array" required={true}>
      A list of objects representing a particular User's approval or rejection of a Consensus request, including all relevant metadata.
    </NestedParam>

    <NestedParam parentKey="activity" childKey="fingerprint" type="string" required={true}>
      An artifact verifying a User's action.
    </NestedParam>

    <NestedParam parentKey="activity" childKey="canApprove" type="boolean" required={true}>
      Whether the activity can be approved.
    </NestedParam>

    <NestedParam parentKey="activity" childKey="canReject" type="boolean" required={true}>
      Whether the activity can be rejected.
    </NestedParam>

    <NestedParam parentKey="activity" childKey="createdAt" type="string" required={true}>
      The creation timestamp.
    </NestedParam>

    <NestedParam parentKey="activity" childKey="updatedAt" type="string" required={true}>
      The last update timestamp.
    </NestedParam>
  </Expandable>
</ResponseField>

<RequestExample>
  ```bash title="cURL" theme={"system"}
  curl --request POST \
    --url https://api.turnkey.com/public/v1/submit/spark_prepare_transfer \
    --header 'Accept: application/json' \
    --header 'Content-Type: application/json' \
    --header "X-Stamp: <string> (see Authorizations)" \
    --data '{
      "type": "ACTIVITY_TYPE_SPARK_PREPARE_TRANSFER",
      "timestampMs": "<string> (e.g. 1746736509954)",
      "organizationId": "<string> (Your Organization ID)",
      "parameters": {
          "signWith": "<spark-address>",
          "transfer": {
              "transferId": "<uuid-v7>",
              "threshold": 2,
              "receiverPublicKey": "<receiver-identity-pubkey-hex>",
              "operatorRecipients": [
                  { "operatorId": "SO1", "encryptionPublicKey": "<so1-pubkey-hex>" },
                  { "operatorId": "SO2", "encryptionPublicKey": "<so2-pubkey-hex>" }
              ],
              "leaves": [
                  {
                      "leafId": "<old-leaf-id>",
                      "oldLeafDerivation": {
                          "signingLeaf": {
                              "leafId": "<old-leaf-id>"
                          }
                      },
                      "newLeafDerivation": {
                          "signingLeaf": {
                              "leafId": "<new-leaf-id>"
                          }
                      },
                      "refundSignature": "<cpfp-aggregated-schnorr-sig-hex>",
                      "directRefundSignature": "<direct-aggregated-schnorr-sig-hex>",
                      "directFromCpfpRefundSignature": "<direct-from-cpfp-aggregated-schnorr-sig-hex>"
                  }
              ]
          }
      }
  }'
  ```

  ```javascript title="JavaScript" theme={"system"}
  import { Turnkey } from "@turnkey/sdk-server";

  const turnkeyClient = new Turnkey({
    apiBaseUrl: "https://api.turnkey.com",
    apiPublicKey: process.env.API_PUBLIC_KEY!,
    apiPrivateKey: process.env.API_PRIVATE_KEY!,
    defaultOrganizationId: process.env.ORGANIZATION_ID!,
  });

  const response = await turnkeyClient.apiClient().sparkPrepareTransfer({
    signWith: "<spark-address>",
    transfer: {
      transferId: "<uuid-v7>",
      threshold: 2,
      receiverPublicKey: "<receiver-identity-pubkey-hex>",
      operatorRecipients: [
        { operatorId: "SO1", encryptionPublicKey: "<so1-pubkey-hex>" },
        { operatorId: "SO2", encryptionPublicKey: "<so2-pubkey-hex>" },
      ],
      leaves: [{
        leafId: "<old-leaf-id>",
        oldLeafDerivation: { signingLeaf: { leafId: "<old-leaf-id>" } },
        newLeafDerivation: { signingLeaf: { leafId: "<new-leaf-id>" } },
        refundSignature: "<cpfp-aggregated-schnorr-sig-hex>",
        directRefundSignature: "<direct-aggregated-schnorr-sig-hex>",
        directFromCpfpRefundSignature: "<direct-from-cpfp-aggregated-schnorr-sig-hex>",
      }],
    },
  });
  ```
</RequestExample>

<ResponseExample>
  ```json 200 theme={"system"}
  {
    "activity": {
      "id": "<activity-id>",
      "status": "ACTIVITY_STATUS_COMPLETED",
      "type": "ACTIVITY_TYPE_SPARK_PREPARE_TRANSFER",
      "organizationId": "<organization-id>",
      "timestampMs": "<timestamp> (e.g. 1746736509954)",
      "result": {
        "activity": {
          "id": "<string>",
          "organizationId": "<string>",
          "status": "<string>",
          "type": "<string>",
          "intent": {
            "prepareSparkTransferIntent": {
              "signWith": "<spark-address>",
              "transfer": "<object>"
            }
          },
          "result": {
            "prepareSparkTransferResult": {
              "operatorPackages": [
                { "operatorId": "SO1", "encryptedPackage": "<hex>" },
                { "operatorId": "SO2", "encryptedPackage": "<hex>" }
              ],
              "transferUserSignature": "<ecdsa-der-sig-hex>"
            }
          },
          "votes": "<array>",
          "fingerprint": "<string>",
          "canApprove": "<boolean>",
          "canReject": "<boolean>",
          "createdAt": "<string>",
          "updatedAt": "<string>"
        }
      }
    }
  }
  ```
</ResponseExample>