Transaction How To's

Base URL: https://developers.bitpowr.com/api/v1

Authentication: Bearer token required in Authorization header

API Endpoints

1. Estimate Transaction Fee

POST /transactions/estimate - Get estimated transaction fees before sending

2. Create Transaction

POST /transactions - Create and send blockchain transactions

Parameter Format Updates

Important: The API supports both legacy and modern parameter formats:

Legacy Format (deprecated): fromAddress, cryptoAmount, address
Modern Format (recommended): from, tos, fromUtxo

Modern Format Structure

from: Array of sender addresses (strings)
tos: Array of objects with address and value properties
fromUtxo: Array of UTXO objects for Bitcoin-like chains

Transaction Fee Estimation

Before creating transactions, you can estimate the required fees using the estimation endpoint.

Endpoint

POST /transactions/estimate

Request Headers

Content-Type: application/json
Authorization: Bearer <encodedToken>

Required Parameters

Parameter	Type	Required	Description
`chain`	string	Yes	Blockchain network (BITCOIN, ETHEREUM, BSC, POLYGON, etc.)
`walletId`	string	Yes	Unique identifier for the wallet
`token`	string	Yes	Token type (USDC, USDT, BTC, etc.)
`tos`	array	Yes	Array of destination objects

Optional Parameters

Parameter	Type	Description
`accountId`	string	Account UID for the transaction
`subAccountId`	string	Sub-account UID
`assetId`	string	Asset UID
`operation`	string	Custom operation (transfer, approve, transferFrom, etc.)
`from`	array	Array of sender addresses
`fromUtxo`	array	UTXO objects for Bitcoin transactions
`feeAddress`	string	Address to pay transaction fees
`spender`	string	Address for approve operations

Example Request

curl --request POST \
     --url https://developers.bitpowr.com/api/v1/transactions/estimate \
     -H 'content-type: application/json' \
     -H 'authorization: Bearer <encodedToken>' \
     -d '{
          "chain": "ETHEREUM",
          "walletId": "e3455-15b5-46ad-84de-34555",
          "token": "USDC",
          "tos": [{
              "address": "0x1180a4c0c71b5eb0256edcffcc3389f1f085c502",
              "value": "9"
          }],
          "from": ["0x40fa00fe4a0a655240fede3149e9ea55118241e2"]
      }'

Response Format

{
  "fee": {
    "fast": {
      "gasFee": "0.000119673736860231",
      "gasLimit": 46467,
      "gasPrice": "2575456493"
    },
    "slow": {
      "gasFee": "0.0000697005",
      "gasLimit": 46467,
      "gasPrice": "1500000000"
    },
    "medium": {
      "gasFee": "0.000049973236860231",
      "gasLimit": 46467,
      "gasPrice": "1075456493"
    }
  }
}

1. Send ERC20 Token Transaction

Send ERC20 tokens on the Ethereum network. Gas fees can be specified manually or calculated automatically.

Endpoint

POST /transactions

Request Headers

Content-Type: application/json
Authorization: Bearer <encodedToken>

Legacy Parameters (Deprecated)

Parameter	Type	Required	Description
`walletId`	string	Yes	Unique identifier for the wallet
`assetType`	string	Yes	Token type (e.g., "TUSDC_ETH")
`cryptoAmount`	string	Yes	Amount of tokens to send
`fromAddress`	string	Yes	Sender's Ethereum address
`address`	string	Yes	Recipient's Ethereum address
`gasLimit`	string	No	Maximum gas units to use
`gasPrice`	string	No	Gas price in wei
`fee`	string	No	Transaction fee in ETH
`description`	string	No	Transaction description

Modern Parameters (Recommended)

Parameter	Type	Required	Description
`walletId`	string	Yes	Unique identifier for the wallet
`assetType`	string	Yes	Token type (e.g., "TUSDC_ETH")
`from`	array	Yes	Array of sender addresses
`tos`	array	Yes	Array of destination objects
`gasLimit`	string	No	Maximum gas units to use
`gasPrice`	string	No	Gas price in wei
`fee`	string	No	Transaction fee in ETH
`description`	string	No	Transaction description

Example Request (Legacy Format)

curl --request POST \
     --url https://developers.bitpowr.com/api/v1/transactions \
     -H 'content-type: application/json' \
     -H 'authorization: Bearer <encodedToken>' \
     -d '{
          "walletId": "e3455-15b5-46ad-84de-34555",
          "assetType": "TUSDC_ETH",
          "cryptoAmount": "9",
          "fromAddress": "0x40fa00fe4a0a655240fede3149e9ea55118241e2",
          "address": "0x1180a4c0c71b5eb0256edcffcc3389f1f085c502",
          "gasLimit": "40000",
          "gasPrice": "2000000009",
          "fee": "0.00018",
          "description": "Testing Here"
      }'

Example Request (Modern Format)

curl --request POST \
     --url https://developers.bitpowr.com/api/v1/transactions \
     -H 'content-type: application/json' \
     -H 'authorization: Bearer <encodedToken>' \
     -d '{
          "walletId": "e3455-15b5-46ad-84de-34555",
          "assetType": "TUSDC_ETH",
          "from": ["0x40fa00fe4a0a655240fede3149e9ea55118241e2"],
          "tos": [{
              "address": "0x1180a4c0c71b5eb0256edcffcc3389f1f085c502",
              "value": "9"
          }],
          "gasLimit": "40000",
          "gasPrice": "2000000009",
          "fee": "0.00018",
          "description": "Testing Here"
      }'

Note: Gas fee parameters (gasLimit, gasPrice, fee) are optional. If not provided, they will be calculated automatically.

2. Send Bitcoin Transaction

Send Bitcoin using standard transaction format.

Legacy Parameters (Deprecated)

Parameter	Type	Required	Description
`walletId`	string	Yes	Unique identifier for the wallet
`assetType`	string	Yes	Must be "BTC"
`cryptoAmount`	string	Yes	Amount of BTC to send
`address`	string	Yes	Recipient's Bitcoin address
`description`	string	No	Transaction description
`fee`	string	Yes	Transaction fee in BTC

Modern Parameters (Recommended)

Parameter	Type	Required	Description
`walletId`	string	Yes	Unique identifier for the wallet
`assetType`	string	Yes	Must be "BTC"
`from`	array	No	Array of sender addresses
`tos`	array	Yes	Array of destination objects
`description`	string	No	Transaction description
`fee`	string	Yes	Transaction fee in BTC

Example Request (Legacy Format)

curl --request POST \
     --url https://developers.bitpowr.com/api/v1/transactions \
     -H 'content-type: application/json' \
     -H 'authorization: Bearer <encodedToken>' \
     -d '{
          "walletId": "8648a91-2413-43dc-a139-667432b8ff",
          "assetType": "BTC",
          "cryptoAmount": "0.00001",
          "address": "2MtQsUJqJz4wiY5WnBXPwrsMbJxm9QsT14i",
          "description": "Testing Here",
          "fee": "0.00000547"
      }'

Example Request (Modern Format)

curl --request POST \
     --url https://developers.bitpowr.com/api/v1/transactions \
     -H 'content-type: application/json' \
     -H 'authorization: Bearer <encodedToken>' \
     -d '{
          "walletId": "8648a91-2413-43dc-a139-667432b8ff",
          "assetType": "BTC",
          "tos": [{
              "address": "2MtQsUJqJz4wiY5WnBXPwrsMbJxm9QsT14i",
              "value": "0.00001"
          }],
          "description": "Testing Here",
          "fee": "0.00000547"
      }'

3. Send TRC20 Transaction

Send TRC20 tokens on the TRON network.

Legacy Parameters (Deprecated)

Parameter	Type	Required	Description
`walletId`	string	Yes	Unique identifier for the wallet
`assetType`	string	Yes	TRC20 token type (e.g., "TUSDC_TRON")
`cryptoAmount`	string	Yes	Amount of tokens to send
`fromAddress`	string	Yes	Sender's TRON address
`address`	string	Yes	Recipient's TRON address
`description`	string	No	Transaction description

Modern Parameters (Recommended)

Parameter	Type	Required	Description
`walletId`	string	Yes	Unique identifier for the wallet
`assetType`	string	Yes	TRC20 token type (e.g., "TUSDC_TRON")
`from`	array	Yes	Array of sender addresses
`tos`	array	Yes	Array of destination objects
`description`	string	No	Transaction description

Example Request (Legacy Format)

curl --request POST \
     --url https://developers.bitpowr.com/api/v1/transactions \
     -H 'content-type: application/json' \
     -H 'authorization: Bearer <encodedToken>' \
     -d '{
          "walletId": "22efe5-1d0a-41ae-9d7f-b22374062",
          "assetType": "TUSDC_TRON",
          "cryptoAmount": "1",
          "fromAddress": "TBnmBzyZs3v5ubdKXNN617Tu4PeLhzLrH7",
          "address": "TD6szM7KukDqCv1FSAm451HDttregBadiU",
          "description": "Testing Here"
      }'

Example Request (Modern Format)

curl --request POST \
     --url https://developers.bitpowr.com/api/v1/transactions \
     -H 'content-type: application/json' \
     -H 'authorization: Bearer <encodedToken>' \
     -d '{
          "walletId": "22efe5-1d0a-41ae-9d7f-b22374062",
          "assetType": "TUSDC_TRON",
          "from": ["TBnmBzyZs3v5ubdKXNN617Tu4PeLhzLrH7"],
          "tos": [{
              "address": "TD6szM7KukDqCv1FSAm451HDttregBadiU",
              "value": "1"
          }],
          "description": "Testing Here"
      }'

4. Send Approve Transaction

Create an approval transaction that allows a spender address to transfer tokens on behalf of the owner. This is required before executing transferFrom transactions.

Use Case

This operation is useful when you want to delegate spending authority to another address, allowing them to pay fees and transfer tokens from your address.

Legacy Parameters (Deprecated)

Parameter	Type	Required	Description
`walletId`	string	Yes	Unique identifier for the wallet
`assetType`	string	Yes	Token type (e.g., "TUSDC_TRON")
`cryptoAmount`	string	Yes	Total amount the spender can spend
`fromAddress`	string	Yes	Token owner's address
`address`	string	Yes	Contract address being approved
`spenderAddress`	string	Yes	Address being granted spending permission
`description`	string	No	Transaction description
`operation`	string	Yes	Must be "approve"

Modern Parameters (Recommended)

Parameter	Type	Required	Description
`walletId`	string	Yes	Unique identifier for the wallet
`assetType`	string	Yes	Token type (e.g., "TUSDC_TRON")
`from`	array	Yes	Array with token owner's address
`tos`	array	Yes	Array with contract address and amount
`spenderAddress`	string	Yes	Address being granted spending permission
`description`	string	No	Transaction description
`operation`	string	Yes	Must be "approve"

Example Request (Legacy Format)

curl --request POST \
     --url https://developers.bitpowr.com/api/v1/transactions \
     -H 'content-type: application/json' \
     -H 'authorization: Bearer <encodedToken>' \
     -d '{
          "walletId": "0722efe5-1d0a-41ae-9d7f-b22374062f81",
          "assetType": "TUSDC_TRON",
          "cryptoAmount": "4000000",
          "fromAddress": "TBnmBzyZs3v5ubdKXNN617Tu4PeLhzLrH7",
          "address": "TKXXPkbtfn9uvwtxf2hdSUQJ2772prGenm",
          "spenderAddress": "TKXXPkbtfn9uvwtxf2hdSUQJ2772prGenm",
          "description": "Approve TKXXPkbtfn9uvwtxf2hdSUQJ2772prGenm",
          "operation": "approve"
      }'

Example Request (Modern Format)

curl --request POST \
     --url https://developers.bitpowr.com/api/v1/transactions \
     -H 'content-type: application/json' \
     -H 'authorization: Bearer <encodedToken>' \
     -d '{
          "walletId": "0722efe5-1d0a-41ae-9d7f-b22374062f81",
          "assetType": "TUSDC_TRON",
          "from": ["TBnmBzyZs3v5ubdKXNN617Tu4PeLhzLrH7"],
          "tos": [{
              "address": "TKXXPkbtfn9uvwtxf2hdSUQJ2772prGenm",
              "value": "4000000"
          }],
          "spenderAddress": "TKXXPkbtfn9uvwtxf2hdSUQJ2772prGenm",
          "description": "Approve TKXXPkbtfn9uvwtxf2hdSUQJ2772prGenm",
          "operation": "approve"
      }'

Important: The value in tos array represents the total allowance the spender address will have, not just the current transaction amount.

5. Send Bitcoin Using UTXO

Send Bitcoin by specifying exact UTXOs (Unspent Transaction Outputs) to use as inputs. This provides more control over transaction construction.

Parameters

Parameter	Type	Required	Description
`walletId`	string	Yes	Unique identifier for the wallet
`assetType`	string	Yes	Must be "BTC"
`fromUtxo`	array	Yes	Array of UTXO objects to spend
`tos`	array	Yes	Array of output destinations
`description`	string	No	Transaction description
`fee`	string	Yes	Transaction fee in BTC
`changeAddress`	string	Yes	Address to receive change

UTXO Object Structure

Parameter	Type	Required	Description
`address`	string	Yes	Address containing the UTXO
`txHash`	string	Yes	Transaction hash of the UTXO
`index`	number	Yes	Output index in the transaction

Output Object Structure

Parameter	Type	Required	Description
`address`	string	Yes	Recipient address
`value`	number	Yes	Amount to send in BTC

Example Request

curl --request POST \
     --url https://developers.bitpowr.com/api/v1/transactions \
     -H 'content-type: application/json' \
     -H 'authorization: Bearer <encodedToken>' \
     -d '{
          "walletId": "4522efe5-1d0a-41ae-9d7f-b22374063332",
          "assetType": "BTC",
          "fromUtxo": [{
              "address": "mufcbAEjrTpC2cyJXSvQFK6wVFgjTxXBbh",
              "txHash": "d2e4d67d78ddc17639f16bb54045fb52519a523fb5e27a2fa97b0e1438c62146",
              "index": 0
          }, {
              "address": "tb1q93vcd7m4vsr8mvxpxdptr4735fzha9gvxhs7hz",
              "txHash": "cbeb2d1872b867e6b35784a8827886fd99b9813d6f3a22ac4c2e05c80cc5596c",
              "index": 1
          }],
          "tos": [{
              "address": "tb1q4qs2y4ex67sxgqfyydqysa78506awdw6nafdfj",
              "value": 0.0001
          }],
          "description": "Testing Here",
          "fee": "0.000001547",
          "changeAddress": "tb1q93vcd7m4vsr8mvxpxdptr4735fzha9gvxhs7hz"
      }'

6. Initiate TransferFrom Transaction

Execute a transferFrom operation using previously approved allowances. This allows a delegated address to transfer tokens on behalf of the owner.

Prerequisites

An approve transaction must be executed first
The feeAddress must have sufficient allowance from the token owner

Legacy Parameters (Deprecated)

Parameter	Type	Required	Description
`walletId`	string	Yes	Unique identifier for the wallet
`assetType`	string	Yes	Token type (e.g., "TUSDC_TRON")
`cryptoAmount`	string	Yes	Amount to transfer
`fromAddress`	string	Yes	Original token owner's address
`address`	string	Yes	Recipient's address
`feeAddress`	string	Yes	Address paying for the transaction
`description`	string	No	Transaction description
`operation`	string	Yes	Must be "transferFrom"

Modern Parameters (Recommended)

Parameter	Type	Required	Description
`walletId`	string	Yes	Unique identifier for the wallet
`assetType`	string	Yes	Token type (e.g., "TUSDC_TRON")
`from`	array	Yes	Array with original token owner's address
`tos`	array	Yes	Array with recipient and amount
`feeAddress`	string	Yes	Address paying for the transaction
`description`	string	No	Transaction description
`operation`	string	Yes	Must be "transferFrom"

Example Request (Legacy Format)

curl --request POST \
     --url https://developers.bitpowr.com/api/v1/transactions \
     -H 'content-type: application/json' \
     -H 'authorization: Bearer <encodedToken>' \
     -d '{
          "walletId": "0722efe5-1d0a-41ae-9d7f-b22374062f81",
          "assetType": "TUSDC_TRON",
          "cryptoAmount": "4000",
          "fromAddress": "TBnmBzyZs3v5ubdKXNN617Tu4PeLhzLrH7",
          "address": "TKXXPkbtfn9uvwtxf2hdSUQJ2772prGenm",
          "feeAddress": "TKXXPkbtfn9uvwtxf2hdSUQJ2772prGenm",
          "description": "Transfer From TKXXPkbtfn9uvwtxf2hdSUQJ2772prGenm",
          "operation": "transferFrom"
      }'

Example Request (Modern Format)

curl --request POST \
     --url https://developers.bitpowr.com/api/v1/transactions \
     -H 'content-type: application/json' \
     -H 'authorization: Bearer <encodedToken>' \
     -d '{
          "walletId": "0722efe5-1d0a-41ae-9d7f-b22374062f81",
          "assetType": "TUSDC_TRON",
          "from": ["TBnmBzyZs3v5ubdKXNN617Tu4PeLhzLrH7"],
          "tos": [{
              "address": "TKXXPkbtfn9uvwtxf2hdSUQJ2772prGenm",
              "value": "4000"
          }],
          "feeAddress": "TKXXPkbtfn9uvwtxf2hdSUQJ2772prGenm",
          "description": "Transfer From TKXXPkbtfn9uvwtxf2hdSUQJ2772prGenm",
          "operation": "transferFrom"
      }'

Transaction Workflow

For Standard Transfers

ERC20/TRC20: Use the respective transaction type directly
Bitcoin: Choose between standard transaction or UTXO-based transaction

For Delegated Transfers

Step 1: Execute an approve transaction to grant spending permission
Step 2: Execute a transferFrom transaction to perform the actual transfer

Error Handling

The API will return appropriate HTTP status codes and error messages for various scenarios:

400 Bad Request: Invalid parameters or malformed request
401 Unauthorized: Invalid or missing authorization token
403 Forbidden: Insufficient permissions
500 Internal Server Error: Server-side processing error

Always check the response status and handle errors appropriately in your application.