> ## Documentation Index > Fetch the complete documentation index at: https://docs.getpara.com/llms.txt > Use this file to discover all available pages before exploring further. # Sign Authorization (EIP-7702) > Signs an EIP-7702 authorization for account delegation. Only supported for EVM wallets. EIP-7702 allows an EOA to delegate execution to a smart contract address for a single transaction, enabling features like gas sponsorship and batched calls without migrating to a new contract wallet address. This is used by account abstraction providers such as ZeroDev, Alchemy, Pimlico, and others operating in 7702 mode. The endpoint computes the authorization hash per EIP-7702 (`keccak256(0x05 || rlp([chainId, address, nonce]))`), signs it via MPC, and returns the decomposed signature with `yParity` (0 or 1) — not the legacy `v` (27/28) used by other signing endpoints. Both `address` and `contractAddress` are accepted in the request body as the delegation target. This matches viem's `signAuthorization` API. ## OpenAPI ````yaml /openapi.yaml post /v1/wallets/{walletId}/sign-authorization openapi: 3.0.3 info: title: Para REST API version: '1.0' description: Server-to-server wallet creation and signing over HTTP servers: - url: https://api.beta.getpara.com description: Beta - url: https://api.getpara.com description: Production security: - ApiKeyAuth: [] paths: /v1/wallets/{walletId}/sign-authorization: post: tags: - Signing summary: Sign Authorization (EIP-7702) description: > Signs an EIP-7702 authorization for account delegation. Only supported for EVM wallets. EIP-7702 allows an EOA to delegate execution to a smart contract address for a single transaction, enabling features like gas sponsorship and batched calls without migrating to a new contract wallet address. This is used by account abstraction providers such as ZeroDev, Alchemy, Pimlico, and others operating in 7702 mode. The endpoint computes the authorization hash per EIP-7702 (`keccak256(0x05 || rlp([chainId, address, nonce]))`), signs it via MPC, and returns the decomposed signature with `yParity` (0 or 1) — not the legacy `v` (27/28) used by other signing endpoints. Both `address` and `contractAddress` are accepted in the request body as the delegation target. This matches viem's `signAuthorization` API. operationId: signAuthorization parameters: - $ref: '#/components/parameters/WalletId' - $ref: '#/components/parameters/RequestId' - $ref: '#/components/parameters/IdempotencyKey' requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/SignAuthorizationRequest' responses: '200': description: Signed authorization content: application/json: schema: $ref: '#/components/schemas/SignAuthorizationResponse' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' '409': $ref: '#/components/responses/IdempotencyConflict' '422': $ref: '#/components/responses/Unprocessable' '429': $ref: '#/components/responses/TooManyRequests' '500': $ref: '#/components/responses/ServerError' components: parameters: WalletId: name: walletId in: path required: true description: Wallet ID schema: type: string example: 0a1b2c3d-4e5f-6789-abcd-ef0123456789 RequestId: name: X-Request-Id in: header required: false description: UUID for request tracing. Para returns one if omitted. schema: type: string format: uuid IdempotencyKey: name: Idempotency-Key in: header required: false description: > Unique key for safe retries on POST endpoints. If a request with the same key is received within 24 hours, the original response is returned without re-executing. Recommended format: UUID v4. Max length 256 characters. Returns 422 if the same key is reused with a different request body. Returns 409 if a request with the same key is still being processed. schema: type: string maxLength: 256 schemas: SignAuthorizationRequest: type: object required: - authorization properties: authorization: type: object required: - chainId - nonce properties: address: type: string description: >- Contract address to delegate execution to. Mutually exclusive with `contractAddress`. example: '0x1234567890abcdef1234567890abcdef12345678' contractAddress: type: string description: >- Alias for `address` (matches viem's API). Mutually exclusive with `address`. example: '0x1234567890abcdef1234567890abcdef12345678' chainId: type: integer minimum: 0 description: >- Chain ID for the authorization. Use 0 for chain-agnostic authorizations. example: 1 nonce: type: integer minimum: 0 description: Account nonce for the authorization. example: 0 SignAuthorizationResponse: type: object required: - address - chainId - nonce - r - s - yParity - signature properties: address: type: string description: Contract address the authorization delegates to. example: '0x1234567890abcdef1234567890abcdef12345678' chainId: type: integer description: Chain ID from the authorization. example: 1 nonce: type: integer description: Nonce from the authorization. example: 0 r: type: string description: ECDSA signature r component (hex with 0x prefix). example: 0xa1b2c3... s: type: string description: ECDSA signature s component (hex with 0x prefix). example: 0xd4e5f6... yParity: type: integer enum: - 0 - 1 description: >- EIP-7702 parity bit (0 or 1). Unlike other signing endpoints that return v (27/28), this uses yParity per the EIP-7702 spec. example: 0 signature: type: string description: Raw hex-encoded 65-byte signature without `0x` prefix (r + s + v). example: a1b2c3d4e5f6... Error: type: object required: - code - message properties: code: type: string description: Machine-readable error code for programmatic handling example: INVALID_REQUEST message: type: string description: Human-readable error message transactionId: type: string format: uuid description: >- Persisted transaction record id. Present only when a broadcast request failed after a history row was created. failureStage: type: string enum: - mpc_sign - signature_apply - signer_verify - broadcast - monitor_timeout description: >- Which stage of the broadcast lifecycle failed. Present on persisted broadcast failures. failureCode: type: string description: >- Machine-readable failure reason from the underlying broadcast helper (e.g. `INSUFFICIENT_NATIVE_BALANCE`, `EXECUTION_FAILED`). Present on broadcast-stage failures. signedTransaction: type: string description: >- Signed transaction bytes. Present on broadcast failures that happen after signing completed. additionalProperties: true description: > All error responses include `code` and `message` fields. Some errors include extra fields (e.g. `walletId` on 409 Conflict). Broadcast failures that occur after a persisted transaction row is created include `transactionId`, `failureStage`, and (on broadcast-stage failures) `failureCode`, and also set the `x-transaction-id` response header. If signing completed before the failure, `signedTransaction` is included so callers can inspect or retry the already-signed bytes. Common error codes: `INVALID_REQUEST`, `UNAUTHORIZED`, `FORBIDDEN`, `NOT_FOUND`, `CONFLICT`, `WALLET_ALREADY_EXISTS`, `WALLET_ALREADY_CLAIMED`, `RATE_LIMITED`, `INTERNAL_ERROR`. responses: BadRequest: description: Invalid request body content: application/json: schema: $ref: '#/components/schemas/Error' example: code: INVALID_REQUEST message: type must be one of EVM, SOLANA, COSMOS, STELLAR Unauthorized: description: API key not provided content: application/json: schema: $ref: '#/components/schemas/Error' example: code: UNAUTHORIZED message: secret api key not provided Forbidden: description: Invalid API key content: application/json: schema: $ref: '#/components/schemas/Error' example: code: FORBIDDEN message: invalid secret api key NotFound: description: Wallet not found content: application/json: schema: $ref: '#/components/schemas/Error' example: code: NOT_FOUND message: wallet not found IdempotencyConflict: description: A request with this idempotency key is currently being processed content: application/json: schema: $ref: '#/components/schemas/Error' example: code: CONFLICT message: A request with this idempotency key is currently being processed Unprocessable: description: Idempotency key reused with a different request body content: application/json: schema: $ref: '#/components/schemas/Error' example: code: UNPROCESSABLE message: >- Idempotency key has already been used with different request parameters TooManyRequests: description: Rate limit exceeded headers: Retry-After: schema: type: integer description: Seconds until the rate limit window resets example: 60 content: application/json: schema: $ref: '#/components/schemas/Error' example: code: RATE_LIMITED message: Rate limit exceeded, try again shortly. ServerError: description: Internal server error content: application/json: schema: $ref: '#/components/schemas/Error' example: code: INTERNAL_ERROR message: Internal Server Error securitySchemes: ApiKeyAuth: type: apiKey in: header name: X-API-Key description: Your partner secret key (server-side only) x-default: sk_your_secret_key_here ````