Create a delegated signing key
Delegate Spark token-transaction signing authority for a card funding source backed by an Embedded Wallet internal account to a Grid-custodied P-256 API key. Grid uses the requested card and internal account to identify the wallet funding source, generates the keypair server-side, creates an isolated signer identity holding the public key, then policies granting that identity signing and self-revocation authority. The private key is custodied by Grid and never returned. Both activities must be authorized by the wallet owner, so creation is a three-leg signed-retry flow:
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Call POST /auth/delegated-keys with no signature headers. Grid generates the delegated keypair and the response is 202 with a payloadToSign, requestId, and expiresAt.
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Use the session API keypair of a verified credential on the requested Embedded Wallet internal account to build an API-key stamp over payloadToSign, then retry the same request with that full stamp as the Grid-Wallet-Signature header and the requestId echoed back as the Request-Id header. The response is a second 202 with a new payloadToSign, requestId, and expiresAt.
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Stamp the new payloadToSign with the same session keypair and retry once more with the new Request-Id. The signed retry returns 201 with the created DelegatedKey in ACTIVE status.
The same request body must be sent on all three legs. A flow abandoned after the second leg leaves the key in PENDING status: the signer identity exists but holds no policies, so it cannot sign or revoke itself. Abandoned PENDING keys do not block creating another delegated key. After activation, Grid uses the custodied key to authorize signing for the card's Embedded Wallet funding account in place of a session keypair; the platform never handles the key material.
Each card funding source may have at most one ACTIVE delegated key for its Embedded Wallet funding account; revoke the existing active key before creating a new one. A delegated key authorizes raw-payload signing for the wallet and cannot be scoped to amounts or recipients by the public API. Revoke it with DELETE /auth/delegated-keys/{id} when no longer needed.
Headers
Full API-key stamp built over the prior payloadToSign with the session API keypair of a verified credential on the same internal account. Required on the signed retries; ignored on the initial call.
The requestId returned in the prior 202 response, echoed back exactly on the signed retry so the server can correlate it with the issued challenge. Required on the signed retries; must be paired with Grid-Wallet-Signature.
Request body
Example request
{
"cardId": "Card:019542f5-b3e7-1d02-0000-000000000010",
"internalAccountId": "InternalAccount:019542f5-b3e7-1d02-0000-000000000002",
"nickname": "Card payments key",
"spendingLimits": [
{
"currencyCode": "USD",
"maxPerTransaction": 5000
}
]
}Response
Delegated key created and policy granted. The key is ACTIVE and Grid may use it to stamp card-payment quote executions for this card funding source's Embedded Wallet funding account.
Example response
{
"id": "DelegatedKey:019542f5-b3e7-1d02-0000-000000000021",
"cardId": "Card:019542f5-b3e7-1d02-0000-000000000010",
"fundingSourceId": "CardFundingSource:019542f5-b3e7-1d02-0000-000000000011",
"accountId": "InternalAccount:019542f5-b3e7-1d02-0000-000000000002",
"publicKey": "02a1b2c3d4e5f60718293a4b5c6d7e8f90a1b2c3d4e5f60718293a4b5c6d7e8f90",
"nickname": "Settlement service key",
"status": "ACTIVE",
"spendingLimits": [
{
"currencyCode": "USD",
"maxPerTransaction": 5000
}
],
"createdAt": "2026-04-08T15:30:01Z",
"updatedAt": "2026-04-08T15:30:42Z"
}