> ## Documentation Index > Fetch the complete documentation index at: https://docs.withconvexity.com/llms.txt > Use this file to discover all available pages before exploring further. # Sign transaction > Signs (and, where applicable, sponsors and submits) a transaction from a derived wallet identified by `addressIndex`. **Asynchronous by default**, like transfers: sponsored signs are validated, recorded, and answered `202` with the `PENDING` transaction while the relay executes on-chain. Poll [Get transaction by id](/api-reference/wallet/get-transaction-by-id) or pass `webhookUrl` to be notified of the outcome (see [Transfer lifecycle](/api-reference/wallet/overview#transfer-lifecycle-and-outcome-delivery)). Pass `waitForCompletion: true` for the legacy synchronous mode, which holds the request open and answers `200` with the relay result (`txHash`, `gasUsed`, `feeWei`). Local-only signing (a non-EVM chain with `addressIndex`; nothing is broadcast) always answers `200` with the signed transaction. Requires the `wallet.hd.sign` capability and an `Idempotency-Key` header. See [Idempotency](/getting-started/conventions#idempotency). ## OpenAPI ````yaml POST /v1/wallet/hd/sign openapi: 3.1.0 info: title: Convexity Infra API version: 1.0.0 description: >- REST API reference for Convexity Infra: the backend services your business integrates to build and operate on-chain products. Every response is wrapped in a `{ status, message, data }` envelope and authorized with an OAuth 2.0 bearer token minted by Auth-Edge. contact: name: Convexity Infra url: https://withconvexity.com email: infra@withconvexity.com servers: - url: https://dev.api.withconvexity.com description: Development security: - bearerAuth: [] tags: - name: Auth-Edge description: >- OAuth 2.0 token issuance. Exchange a project API key for a short-lived bearer token that authorizes every other Infra API call. - name: Projects description: >- Manage the calling project itself: rotate its API key pair and control which IP addresses may authenticate with it. - name: Payments description: >- List project and subscription payments, and mint virtual bank accounts (via KoraPay) for wallet top-ups and subscriptions. - name: Products description: >- Browse the products and capabilities available to your project. Each product maps to a plan and a set of capability keys. - name: Subscriptions description: List available plans and manage your project's subscriptions. - name: Wallet description: >- HD wallet lifecycle, balances, transfers, transaction signing, and supported-chain discovery. Wallets are scoped to the business in your token: accessing another business's wallet returns `403`. **Capabilities**: each operation is gated on a capability granted by your plan; a missing one returns `403: Missing required capability: `. | Capability | Grants | |---|---| | `wallet.hd.generate` | Generate wallets. | | `wallet.hd.read` | List and read wallets, counts, and HD status. | | `wallet.hd.sign` | Sign transactions. | | `wallet.hd.deactivate` | Deactivate a wallet. | | `wallet.transfer.create` | Initiate transfers. | | `wallet.transfer.read` | Read transaction history and records. | | `wallet.balance.read` | Read the USD balance. | - name: Indexer description: >- Subscribe to decoded on-chain events, receive signed webhooks, and inspect or replay delivery logs. Every endpoint requires a token with project + business context and a per-operation capability. - name: Tokenization description: >- Issue and manage tokenized real-world assets: create tokens, mint, burn, transfer, manage holders and registered wallets, and run yield operations (coupons, distributions, claims, and principal redemption). paths: /v1/wallet/hd/sign: post: tags: - Wallet summary: Sign transaction description: >- Signs (and, where applicable, sponsors and submits) a transaction from a derived wallet identified by `addressIndex`. **Asynchronous by default**, like transfers: sponsored signs are validated, recorded, and answered `202` with the `PENDING` transaction while the relay executes on-chain. Poll [Get transaction by id](/api-reference/wallet/get-transaction-by-id) or pass `webhookUrl` to be notified of the outcome (see [Transfer lifecycle](/api-reference/wallet/overview#transfer-lifecycle-and-outcome-delivery)). Pass `waitForCompletion: true` for the legacy synchronous mode, which holds the request open and answers `200` with the relay result (`txHash`, `gasUsed`, `feeWei`). Local-only signing (a non-EVM chain with `addressIndex`; nothing is broadcast) always answers `200` with the signed transaction. Requires the `wallet.hd.sign` capability and an `Idempotency-Key` header. See [Idempotency](/getting-started/conventions#idempotency). operationId: signTransaction parameters: - name: Idempotency-Key in: header required: true schema: type: string example: 0c1d2e3f-4a5b-6c7d-8e9f-001122334455 description: >- Unique client-generated key (use a UUID) that makes this request safe to retry. A retry sent with the same key returns the original result instead of submitting again. See [Idempotency](/getting-started/conventions#idempotency). requestBody: required: true content: application/json: schema: type: object required: - chainType - addressIndex - transaction properties: chainType: type: string enum: - EVM - SOLANA addressIndex: type: integer description: HD index of the signing wallet. chainId: type: integer description: Target chain id (e.g. `8453`). Required for EVM. network: type: string enum: - MAINNET - TESTNET transaction: type: object required: - to properties: to: type: string description: Recipient address. value: type: string description: Native value in smallest unit. data: type: string description: Calldata (hex). waitForCompletion: type: boolean description: >- Optional. `true` = legacy synchronous mode: hold the request open for the relay outcome (`200` with `txHash`) instead of `202` + poll. Defaults to `false`. webhookUrl: type: string format: uri maxLength: 2048 description: >- Optional. POST the final transaction here once execution settles (`wallet.sign.completed` / `wallet.sign.failed`). HTTPS only in production; private/internal hosts rejected. Delivery is signed and retried. See [Outcome webhook](/api-reference/wallet/overview#outcome-webhook). webhookSecret: type: string minLength: 16 maxLength: 256 description: >- Optional (requires `webhookUrl`). Your own HMAC key for the webhook signature: verify deliveries with the value you sent. Held in memory only; never persisted or logged. examples: asyncWithWebhook: summary: Sponsored sign (async + webhook) value: chainType: EVM chainId: 8453 addressIndex: 12 transaction: to: '0x2222222222222222222222222222222222222222' value: '0' data: 0xa9059cbb… webhookUrl: https://example.com/hooks/wallet webhookSecret: a-secret-you-generate-and-keep waitForCompletion: summary: Legacy synchronous mode value: chainType: EVM chainId: 8453 addressIndex: 12 transaction: to: '0x2222222222222222222222222222222222222222' value: '0' data: 0xa9059cbb… waitForCompletion: true responses: '200': description: OK content: application/json: schema: type: object example: status: true message: Transaction signed successfully data: signedTransaction: 0x02f8b18221058084...c0a0e1 '202': description: >- Accepted (default for sponsored signs): the sign is recorded and relaying. Poll `GET /v1/wallet/transaction/{transactionId}` until `status` is `COMPLETED` or `FAILED`, or receive the outcome at `webhookUrl`. content: application/json: example: status: true message: Sign accepted data: id: 9a1b2c3d-4e5f-6071-8293-a4b5c6d7e8f9 type: CONTRACT_CALL chainType: EVM network: MAINNET chainId: 8453 signerType: BUSINESS_HD fromAddress: '0x71C7656EC7ab88b098defB751B7401B5f6d8976F' addressIndex: 12 toAddress: '0x2222222222222222222222222222222222222222' amount: null tokenAddress: null data: 0xa9059cbb… value: '0' txHash: null status: PENDING gasUsed: null feeWei: null explorerUrl: https://basescan.org explorerTxUrl: null createdAt: '2026-07-12T10:00:00.000Z' updatedAt: '2026-07-12T10:00:00.000Z' '400': description: Bad request content: application/json: schema: type: object example: status: false message: 'chainId: chainId is required when addressIndex is provided' '401': description: Unauthorized content: application/json: schema: type: object example: status: false message: Authorization token is missing or malformed. '402': description: Payment required content: application/json: schema: type: object example: status: false message: No subscription found for this product's plan '403': description: Forbidden content: application/json: schema: type: object examples: 403_Forbidden_test_token: summary: 403 Forbidden – test token value: status: false message: Test tokens are not allowed, please use your live api key. 403_Forbidden_capability_not_granted: summary: 403 Forbidden – capability not granted value: status: false message: Capability wallet.hd.sign not granted '429': description: Too many requests content: application/json: schema: type: object example: status: false message: Too many requests. Please try again later. retryAfter: 60 components: securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: JWT description: OAuth 2.0 access token from Auth-Edge. ````