> ## Documentation Index > Fetch the complete documentation index at: https://docs.brickken.com/llms.txt > Use this file to discover all available pages before exploring further. # newSto > **Description:** This endpoint prepares unsigned transactions for the method selected in the `method` field. For exact required and optional body fields, use the method-specific endpoints under Create Transaction. **Headers:** - `x-api-key`: `YOUR_API_KEY` for API-key auth, or `X-Payment` for x402 retries on eligible agentic methods - `Content-Type`: `application/json` **Common Request Body Parameters:** - `method` (string, required): Operation to prepare. - `chainId` (string, required): Blockchain network identifier. Hex format is recommended, for example `aa36a7` for Sepolia. - `signerAddress` (string, conditionally required): Wallet address that signs the prepared transaction. Most methods require it; `newInvest` and `claimTokens` can use `investorAddress` as the signer. - `gasLimit` (string, optional): Gas limit override. If omitted, the API estimates gas automatically. - `privateRpcUrl` (string, optional): Private RPC URL override. - `nonce` (integer, optional): Nonce override. If omitted, the API reads the pending nonce from the RPC. Prepares unsigned transactions for creating a new Security Token Offering (STO). Use `POST /prepare-transactions` with `method=newSto`. ## Next step Preparing does not touch the chain. The response gives you `txId` and an array of unsigned `transactions` — you still have to sign and submit them. Sign each entry locally with the wallet matching `signerAddress`. It must be whitelisted by Brickken, and it needs native gas on the target chain. `POST` them to [`/send-transactions`](/api-reference/endpoint/send) as `{ txId, signedTransactions }` and Brickken broadcasts for you. If you would rather broadcast yourself, prepare with `executionMode: "client-broadcast"` and confirm afterwards with `{ txId, txHash }` instead. Call [`GET /get-transaction-status`](/api-reference/endpoint/get-transaction-status) with the `txId`. A `pending` status means it is broadcast but not yet mined — do not resubmit. Full walkthrough: [Tokenize an asset and run an STO](/api-reference/guides/tokenize-and-run-an-sto). ## OpenAPI ````yaml POST /prepare-transactions openapi: 3.1.0 info: title: Brickken API V2 description: >- Welcome to the Brickken API documentation. This API allows customers to create and manage tokenization processes, including creating new tokenizations, minting/burning/transferring tokens, whitelisting users, manage tokens approvals. This documentation provides detailed information on how to use the API, including the necessary endpoints, request formats, and expected responses.
**Authentication**All API requests require an API key for authentication. Include your API key in the `x-api-key` header of each request:
```
      x-api-key: YOUR_API_KEY
    ```
Ensure that your API key is kept secure and not shared publicly. A common parameter for all requests is the `signerAddress`. Such address MUST be whitelisted in our factory. To whitelist an address and/or request an API key either for sandbox/production environment please contact with: tech@brickken.com. Once a `signerAddress` performs a `newTokenization` we refer to that address as the tokenizer. The tokenizer will be the only one allowed to mint such token, distribute dividends on such token and whitelist/blacklist investors of such token. Regarding actions like transferring tokens or burning tokens, the `signerAddress` can be any user and not only the tokenizer.
**Supported Networks & Addresses**
Sepolia (sandbox environment only)
```
      Chain Id: "aa36a7"
      Factory Address: "0x933ABAA95a7Fd0Bc683bDe2adB89f4C5EA64897b"
      BKN Address: "0x97a13487f889dc770Ac925Be2d3b6c833FA7746a"
      USDT Address: "0x28d2B01854D0aBec267a3DDcad9163580E6E8604"
      USDC Address: "0xb10cE8e28aEb1ae27b968Fb3bfed2FD7dd52daCb"
    ```
Base Sepolia (sandbox / testing)
```
      Chain Id: "84532" (hex "14a34")
      x402 USDC (Circle, EIP-3009): "0x036CbD53842c5426634e7929541eC2318f3dCF7e"
      ERC-8004 Identity Registry: "0x8004A818BFB912233c491871b3d84c89A494BD9e"
      ERC-8004 Reputation Registry: "0x8004B663056A597Dffe9eCcC1965A193B7388713"
    ```
Ethereum mainnet (production environment only)
```
      Chain Id: "1"
      Factory Address: "0x91af681C85Ca98Efc5D69C1B62E6F435030969Db"
      BKN Address: "0x0A638F07ACc6969abF392bB009f216D22aDEa36d"
      USDT Address: "0xdac17f958d2ee523a2206206994597c13d831ec7"
      USDC Address: "0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48"
    ```
Base mainnet (production environment only)
```
      Chain Id: "2105"
      Factory Address: "0x278D7bdc2451B0Fa4087A68ce084a86cB91D4d83"
      BKN Address: "0xddB293BB5C5258F7484A94a0fBd5c8B2F6E4e376"
      USDT Address: N/A
      USDC Address: "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913"
    ```
BNB Smart Chain mainnet (production environment only)
```
      Chain Id: "38"
      Factory Address: "0xCe4529Fe88df480BD777d3e32dfD7032e6C685ff"
      BKN Address: "0x0e28bC9B03971E95acF9ae1326E51ecF9C55B498"
      USDT Address: "0x55d398326f99059fF775485246999027B3197955"
      USDC Address: "0x8AC76a51cc950d9822D68b83fE1Ad97B32Cd580d"
    ```
Avalance C Chain mainnet (production environment only)
```
      Chain Id: "a86a"
      Factory Address: "0xc6c230FA8F40022dE997727436Fae01caAbcDe61"
      BKN Address: "0xd44E4Dc8bdF7C1c62CfDBb182022097BA42Ac6bC"
      USDT Address: "0x9702230A8Ea53601f5cD2dc00fDBc13d4dF4A8c7"
      USDC Address: "0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E"
    ```
**Usage Workflow**
1. **Prepare Transactions:**- Use the `POST /prepare-transactions` endpoint with the desired method (e.g., `newTokenization`, `mintToken`, etc...) to prepare the transaction(s). - The response will include an array of unsigned transactions that needs to be signed.
**Example Of An Endpoint Response:**```json { "transactions": [ { "from": "0xSignerAddress", "to": "0xTargetAddress", "value": { "type": "BigNumber", "hex": "0x00" }, "nonce": 1, "chainId": 11155111, "data": "0x...", "type": 2, "maxPriorityFeePerGas": { "type": "BigNumber", "hex": "0x..." }, "maxFeePerGas": { "type": "BigNumber", "hex": "0x..." }, "gasLimit": { "type": "BigNumber", "hex": "0x..." } } ] } ```
2. **Sign the Transactions:**- Use your preferred method or wallet to sign the transaction data provided in the response. - Ensure that the signer address matches the `signerAddress` provided in the initial request.
**Example Of signing a transaction with typescript and `ethers-js`:**```typescript const tx = {...} // One of the object in the array returned by the `/prepare-transactions` endpoint const privateKey = process.env.PRIVATE_KEY; const wallet = new ethers.Wallet(privateKey); const signedTx = await wallet.signTransaction(tx); console.log('Signed Transaction:', signedTx); ```
**NOTE:** Be sure to have enough funds in the signer wallet to cover for the transaction cost
3. **Submit Signed Transactions:**- Use the `POST /send-transactions` endpoint to submit the signed transaction(s) along with the required parameters. - The API will process the transactions, send them to the blockchain, and update the Brickken database accordingly.
4. **Check Transaction Status:**- Use the `GET /get-transaction-status` endpoint to check the status of your transaction. - Provide either the on-chain transaction hash (`hash`) or the internal transaction ID (`txId`) to retrieve the status.
**Environments**The API is available in several environments for testing and production purposes:- Sandbox: `https://api.sandbox.brickken.com/` - Master (Production): `https://api.brickken.com/`
The API also exposes x402scan discovery facade endpoints under /x402/... The public discovery target is https://api.brickken.com, with /.well-known/x402 returning resource URLs and /openapi.json returning the generated OpenAPI 3.1 document. version: 2.0.0 servers: - url: https://api.sandbox.brickken.com description: Sandbox Environment - url: https://api.brickken.com description: Production Environment security: - apiKeyAuth: [] paths: /prepare-transactions: post: tags: - Endpoints summary: Prepare Transactions description: >- **Description:** This endpoint prepares unsigned transactions for the method selected in the `method` field. For exact required and optional body fields, use the method-specific endpoints under Create Transaction. **Headers:** - `x-api-key`: `YOUR_API_KEY` for API-key auth, or `X-Payment` for x402 retries on eligible agentic methods - `Content-Type`: `application/json` **Common Request Body Parameters:** - `method` (string, required): Operation to prepare. - `chainId` (string, required): Blockchain network identifier. Hex format is recommended, for example `aa36a7` for Sepolia. - `signerAddress` (string, conditionally required): Wallet address that signs the prepared transaction. Most methods require it; `newInvest` and `claimTokens` can use `investorAddress` as the signer. - `gasLimit` (string, optional): Gas limit override. If omitted, the API estimates gas automatically. - `privateRpcUrl` (string, optional): Private RPC URL override. - `nonce` (integer, optional): Nonce override. If omitted, the API reads the pending nonce from the RPC. requestBody: required: true content: application/json: schema: type: object properties: method: type: string example: newTokenization enum: - newTokenization - newSto - newInvest - claimTokens - mintToken - whitelist - approve - burnToken - transferFrom - transferTo - dividendDistribution - closeOffer - newTokenizedAgent - agentRegister - agentSetURI - agentSetMetadata - agentSetWallet - agentTransferOwnership - agentGiveFeedback - agentRevokeFeedback - agentAppendFeedbackResponse - agentCreateToken - agentMintToken - agentBurnToken - agentTransferToken - agentTransferFromToken - agentApproveToken description: >- The operation to be performed. Includes standard tokenization methods and x402-eligible agentic methods. Agentic methods can also be addressed through /x402/... facade endpoints, where the method is derived from the path. newTokenizedAgent remains a legacy alias for direct /prepare-transactions calls and is not listed in x402scan discovery. signerAddress: type: string description: >- Optional. Wallet address that will sign the prepared transaction. If omitted, the API uses investorAddress for this method. example: '0x742d35Cc6634C0532925a3b8D4C9db96c4b4d8b' chainId: type: string description: >- Required. Blockchain network identifier. Hex format is recommended, for example Sepolia `aa36a7`. example: aa36a7 tokenSymbol: type: string description: >- Required. Token symbol. Must be 2 to 5 uppercase letters or numbers. example: EXMPL tokenType: type: string enum: - EQUITY - DEBT - BILL_FACTORING - ICO - STABLECOIN - REVENUE_SHARE - RWA_TOKEN - PROFIT_SHARING example: EQUITY description: Optional. Token type. Defaults to EQUITY when omitted. tokenizerEmail: type: string description: >- Optional. Tokenizer email. Required for newTokenization, newSto, and closeOffer. example: tokenizer@example.com format: email acceptedCoin: type: string description: Required. Accepted payment token symbol. example: USDT amount: type: string description: >- Optional. Amount used by approve, burnToken, transferFrom, transferTo, and dividendDistribution. example: '100' endDate: type: string description: Required. STO end date. example: '2026-12-31T23:59:59.000Z' format: date-time from: type: string description: Optional. Source address required by transferFrom. example: '0x1111111111111111111111111111111111111111' pattern: ^0x[a-fA-F0-9]{40}$ gasLimit: type: string description: >- Optional. Gas limit override. If omitted, the API estimates gas automatically. example: '2000000' initialHolders: type: array description: >- Optional. Initial holders paired by index with preMints. Provide walletAddress directly, or email when a DFNS wallet can be resolved. items: type: object properties: walletAddress: type: string description: Optional. Holder wallet address. example: '0x1111111111111111111111111111111111111111' pattern: ^0x[a-fA-F0-9]{40}$ email: type: string description: >- Optional. Holder email used to resolve a DFNS wallet when walletAddress is omitted. example: holder@example.com format: email example: - walletAddress: '0x1111111111111111111111111111111111111111' investmentAmount: type: string description: Required. Payment-token amount to invest. example: '1000' investorAddress: type: string description: >- Optional. Investor wallet address. Required for newInvest and claimTokens; optional for approve payment-token owner scope. example: '0x1111111111111111111111111111111111111111' pattern: ^0x[a-fA-F0-9]{40}$ investorEmail: type: string description: >- Optional. Investor email. Required for newInvest, claimTokens, burnToken, and each whitelist/mint recipient. example: investor@example.com format: email maxInvestment: type: string description: Required. Maximum investment amount. example: '10000' maxRaiseUSD: type: string description: Required. Maximum raise amount in USD. example: '100000' minInvestment: type: string description: Required. Minimum investment amount. example: '100' minRaiseUSD: type: string description: Required. Minimum raise amount in USD. example: '10000' name: type: string description: Required. Name of the tokenized asset. example: Example Token newInvestor: type: object description: >- Optional. Default profile data used when creating missing investor users. properties: name: type: string description: Optional. Investor first name. example: John surname: type: string description: Optional. Investor surname. example: Doe middleName: type: string description: Optional. Investor middle name. example: A. secondSurname: type: string description: Optional. Investor second surname. example: Smith type: type: string description: Optional. Investor type. Defaults to INVESTOR_PERSON. example: INVESTOR_PERSON offeringName: type: string description: Required. Name of the STO offering. example: Series A paymentTokenSymbol: type: string description: >- Optional. Payment token symbol used by newInvest. If omitted, the chain default payment token is used. example: USDT preMints: type: array description: >- Optional. Pre-mint amounts. If provided, initialHolders must also be provided with the same length. items: type: object required: - amount properties: amount: type: string description: >- Required. Amount to pre-mint to the holder at the same array index. example: '1000' example: - amount: '1000' privateRpcUrl: type: string description: >- Optional. Private RPC URL override. If omitted, the API uses the configured RPC for chainId. example: https://rpc.example.com spenderAddress: type: string description: Optional. Spender address required by approve. example: '0x3333333333333333333333333333333333333333' pattern: ^0x[a-fA-F0-9]{40}$ startDate: type: string description: Required. STO start date. example: '2026-09-01T00:00:00.000Z' format: date-time supplyCap: type: string description: >- Optional. Maximum token supply. Defaults to `0` when omitted. example: '1000000' to: type: string description: >- Optional. Destination address required by transferFrom and transferTo. example: '0x2222222222222222222222222222222222222222' pattern: ^0x[a-fA-F0-9]{40}$ tokenAmount: type: string description: Required. Number of tokens offered in the STO. example: '1000' tokenizerAddress: type: string description: >- Optional. Tokenizer wallet address used by tokenization setup flows when provided. example: '0x4444444444444444444444444444444444444444' pattern: ^0x[a-fA-F0-9]{40}$ url: type: string description: >- Optional. Token documentation URL. Defaults to an empty string when omitted. example: https://example.com/token-docs userToMint: type: array minItems: 1 description: Required. Users to mint tokens to. items: type: object required: - investorEmail - amount properties: investorEmail: type: string description: Required. Recipient investor email. example: investor@example.com format: email amount: type: string description: Required. Positive whole-token amount to mint. example: '100' investorAddress: type: string description: >- Optional. Recipient wallet address. If omitted, the API attempts to create or resolve a DFNS wallet. example: '0x1111111111111111111111111111111111111111' pattern: ^0x[a-fA-F0-9]{40}$ needWhitelist: type: boolean description: >- Optional. Whether the recipient should be whitelisted before minting. Defaults to true unless explicitly false. example: true name: type: string description: >- Optional. Investor first name used when creating a new investor record. example: John surname: type: string description: >- Optional. Investor surname used when creating a new investor record. example: Doe example: - investorEmail: investor@example.com investorAddress: '0x1111111111111111111111111111111111111111' amount: '100' needWhitelist: true userToWhitelist: type: array minItems: 1 description: Required. Users to whitelist or blacklist. items: type: object required: - investorAddress - investorEmail - whitelistStatus properties: investorAddress: type: string description: Required. Investor wallet address. example: '0x1111111111111111111111111111111111111111' pattern: ^0x[a-fA-F0-9]{40}$ investorEmail: type: string description: Required. Investor email used for the investor record. example: investor@example.com format: email whitelistStatus: type: boolean description: Required. `true` to whitelist, `false` to blacklist. example: true example: - investorAddress: '0x1111111111111111111111111111111111111111' investorEmail: investor@example.com whitelistStatus: true ownerEmail: type: string example: owner@example.com description: Tokenizer owner email used by agentic methods. email: type: string example: reviewer@example.com description: Tracking email used by feedback and agent token methods. services: type: array items: type: object description: Agent service descriptors used by agentRegister. metadata: type: object description: Agent metadata stored in the registration file. aiModelName: type: string example: gpt-4o description: AI model name for agent registration or metadata updates. aiModelProvider: type: string example: openai description: AI model provider stored in the agent profile. agentUuid: type: string description: Internal tokenized agent UUID returned by agentRegister. agentId: oneOf: - type: string - type: number description: On-chain ERC-8004 agent ID. metadataKey: type: string example: modelName description: Metadata key used by agentSetMetadata. metadataValue: description: Metadata value used by agentSetMetadata. metadataEncoding: type: string enum: - string - json - hex description: Encoding mode for agentSetMetadata. newWallet: type: string description: Agent wallet assigned by agentSetWallet. signature: type: string description: Hex signature used by agentSetWallet. deadline: oneOf: - type: string - type: number description: Signature deadline used by agentSetWallet. feedbackIndex: oneOf: - type: string - type: number description: Feedback index used by reputation methods. clientAddress: type: string description: Reviewer/client address used by agentAppendFeedbackResponse. responseURI: type: string description: Off-chain response URI used by agentAppendFeedbackResponse. feedbackURI: type: string description: Off-chain feedback URI used by agentGiveFeedback. feedbackHash: type: string description: Optional 32-byte content hash for feedback. responseHash: type: string description: Optional 32-byte content hash for a feedback response. agentWallet: type: string description: Operational agent wallet used by agentCreateToken. symbol: type: string example: MAT description: Agent token symbol used by agentCreateToken. premint: type: string description: Human-readable premint amount used by agentCreateToken. decimals: type: number description: Agent token decimals. Defaults to 18. tokenAddress: type: string description: >- Deployed agent token address used by agentMintToken and agentBurnToken. x402Support: type: boolean description: >- Whether the registered agent declares x402 support in its profile. active: type: boolean description: Whether the registered agent should appear active. nonce: type: integer description: >- Optional. Nonce override. If omitted, the API reads the pending nonce from the RPC. example: 12 paymentTokenAddress: type: string description: >- Optional. Payment token contract address override. If omitted, the chain default payment token is used. example: '0x5555555555555555555555555555555555555555' pattern: ^0x[a-fA-F0-9]{40}$ required: - method - chainId example: method: newTokenization signerAddress: '0x742d35Cc6634C0532925a3b8D4C9db96c4b4d8b' chainId: aa36a7 tokenizerEmail: tokenizer@example.com name: Example Token tokenSymbol: EXMPL tokenType: EQUITY supplyCap: '1000000' url: https://example.com/token-docs preMints: - amount: '1000' initialHolders: - walletAddress: '0x1111111111111111111111111111111111111111' example: method: newTokenization signerAddress: '0x742d35Cc6634C0532925a3b8D4C9db96c4b4d8b' chainId: aa36a7 tokenizerEmail: tokenizer@example.com name: Example Token tokenSymbol: EXMPL tokenType: EQUITY supplyCap: '1000000' url: https://example.com/token-docs preMints: - amount: '1000' initialHolders: - walletAddress: '0x1111111111111111111111111111111111111111' responses: '200': description: Successful response content: application/json: schema: type: object properties: transactions: type: array description: Array of unsigned transaction objects ready for signing items: type: object properties: from: type: string description: Sender address example: '0x1234567890abcdef1234567890abcdef12345678' to: type: string description: Recipient address example: '0xabcdef1234567890abcdef1234567890abcdef12' value: type: string description: Transaction value in hex example: '0x00' nonce: type: integer description: Transaction nonce example: 3792 chainId: type: integer description: Blockchain network chain ID example: 11155111 data: type: string description: Transaction data payload example: >- 0xd362e8a70000000000000000000000000000000000000000000000000000000000000040... type: type: integer description: Transaction type (EIP-1559) example: 2 maxPriorityFeePerGas: type: string description: Maximum priority fee per gas example: '1150000' maxFeePerGas: type: string description: Maximum fee per gas example: '1156037' gasLimit: type: string description: Gas limit in hex example: '0xccef' info: type: object description: Metadata about the operation properties: tokenizerEmail: type: string description: Email of the tokenizer example: tokenizer@example.com tokenSymbol: type: string description: Symbol of the token example: EXMPL investorEmail: type: string description: Email of the investor (when applicable) example: investor@example.com txId: type: string description: >- Unique identifier for this transaction batch (required for /send-transactions). This is NOT a blockchain transaction hash. example: >- 0x46adea7bdf49c576a760102e0d6bc9ecd650b3998588cd3d7f576a7973426aad required: - transactions - txId '402': description: >- x402 payment required. The response includes a PAYMENT-REQUIRED header with a base64-encoded x402 payment request. security: - apiKeyAuth: [] - x402Payment: [] components: securitySchemes: apiKeyAuth: type: apiKey in: header name: x-api-key x402Payment: type: apiKey in: header name: X-Payment description: >- Base64-encoded x402 payment payload. Supported for x402-eligible agentic methods on /x402/... facades, /prepare-transactions, and eligible /send-transactions retries. ````