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IntroductionAPI Reference
Deprecated APIs

Create a webhook subscription

Register an HTTPS endpoint to receive webhook events for deposit-address transfers. Requires an API key with the deposit-address permission (Bearer auth). A subscription is persistent: it receives every matching event — across all of your deposit addresses — until you delete it. A 2xx response to a delivery only acknowledges that one event; it does not end the subscription. The signing secret is returned once in this response and never again — store it to verify delivery signatures.

POST
/v1/webhooks/subscriptions

Authorization

bearerAuth
AuthorizationBearer <token>

API key for authentication.

In: header

Request Body

application/json

TypeScript Definitions

Use the request body type in TypeScript.

Response Body

application/json

application/json

application/json

application/json

application/json

application/json

Callbacks

event

curl -X POST "https://api.staging.across.to/v1/webhooks/subscriptions" \  -H "Content-Type: application/json" \  -d '{    "url": "https://example.com/webhooks/across",    "filter": {      "eventTypes": [        "pda_transfer.deposit-pending"      ]    }  }'
{
  "id": "whsub_1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d",
  "secret": "whsec_kZ3vN8pXqLmR2sT5wY7bC1dF4gH6jK9n",
  "secretHash": "9f2c3b7a1e4d5f6089ab2c3d4e5f60718293a4b5c6d7e8f9012345678abcdef0"
}
{
  "error": "ValidationError",
  "message": "At path: filter -- Expected an object, but received: undefined"
}
{
  "error": "UnauthorizedError",
  "message": "A valid Authorization: Bearer <apiKey> header is required."
}
{
  "error": "ForbiddenError",
  "message": "API key lacks the 'deposit-address' permission."
}
{
  "error": "ConflictError",
  "message": "A subscription with this url already exists for this integrator."
}
{
  "error": "ValidationError",
  "message": "Invalid request body"
}

Submit a signed gasless swap POST

Submits the signatures for a gasless swap quote from `GET /swap/gasless`. On direct EVM routes the quote returns a single `swapTx` — sign its `typedData` and submit `{ swapTx, signature }`. For HyperCore origin routes (e.g. Hyperliquid withdrawals), the quote returns the steps to sign in `swapTxns[]`. Have the user sign each step, then submit `{ swapTx, swapTxns, signaturesByStepId }`. One signature per step, keyed by the step's stepId. Pass `swapTx` and `swapTxns` through from the quote unchanged. Across submits the transactions and covers the gas. Returns a depositId for tracking the deposit.

List webhook subscriptions GET

List the webhook subscriptions owned by the caller's API key, oldest first. The raw signing secret is never included — only its `secretHash`.