Blockchain Wallet API V2

Programmatically interface with your Blockchain.info wallet.

Contents

• Getting Started
• Upgrading
• API Documentation
• Installation
• Troubleshooting
• Usage
• Development
• Deployment

Getting Started

To use this API, you will need to run small local service which be responsible for managing your Blockchain.info wallet. Your application interacts with this service locally via HTTP API calls.

Start by completing the following steps:

1. Follow the installation instructions
2. Start the server: $ blockchain-wallet-service start --port 3000
3. Reference the documentation and start interacting with your wallet programmatically!

Note that blockchain-wallet-service is designed to be run locally on the same machine as your application and therefore will only accept connections from localhost. If you modify this service to accept external connections, be sure to add the appropriate firewall rules to prevent unauthorized use.

Upgrading

If you already have an application that uses Blockchain.info's Wallet API, you will need to complete the steps in the Getting Started section above and then complete the following:

1. In your application code, replace calls to blockchain.info/merchant/... with localhost:<port>/merchant/...
2. Add an initial call, during your application's initialization, that calls /login with your wallet GUID and password. This call must be made before programmatically accessing your wallet. If your application interacts with more than one wallet, you must call the /login endpoint to switch between wallets. Subsequent calls made to any endpoint will use the last logged-in wallet.

API Documentation

View the original documentation.

All endpoints present in the API documentation above are supported in Blockchain Wallet API V2. The differences between two are:

1. The /login endpoint that must be called prior to accessing a wallet
2. The "consolidate addresses" endpoint has been omitted

All endpoints can be called with GET or POST, and can only be accessed from localhost.

Logging into a Wallet

Loads a blockchain.info wallet. A wallet must be loaded via this endpoint before any other api interactions can occur.

Endpoint: /merchant/:guid/login

Query Parameters:

• password - main wallet password (required)
• api_code - blockchain.info wallet api code (required)

Get an API code here. Note: You must check the "Create Wallets" checkbox under "Permissions" when requesting an API code in order for it to be compatible with this app.

The api_code parameter is only required for the call to /login. Subsequent API calls for this wallet will not require the api code.

Note: at the moment, only one wallet can be "logged into" at a time. To make api calls to different wallets, run separate instances of this service for each wallet, or just remember to call /login each time you want to switch wallets.

Make Payment

Endpoint: /merchant/:guid/payment

Query Parameters:

• to - bitcoin address to send to (required)
• amount - amount in satoshi to send (required)
• password - main wallet password (required)
• second_password - second wallet password (required, only if second password is enabled)
• from - bitcoin address to send from (optional)
• fee - specify transaction fee in satoshi (optional, otherwise fee is computed)
• note - public note to include with the transaction (optional, limit 255 characters)

Sample Response:

{
  "to" : ["1A8JiWcwvpY7tAopUkSnGuEYHmzGYfZPiq"],
  "from": ["17p49XUC2fw4Fn53WjZqYAm4APKqhNPEkY"],
  "amounts": [200000],
  "fee": 1000,
  "txid": "f322d01ad784e5deeb25464a5781c3b20971c1863679ca506e702e3e33c18e9c",
  "success": true
}

Send to Many

Endpoint: /merchant/:guid/sendmany

Query Parameters:

• recipients - a URI encoded JSON object, with bitcoin addresses as keys and the satoshi amounts as values (required, see example below)
• password - main wallet password (required)
• second_password - second wallet password (required, only if second password is enabled)
• from - bitcoin address to send from (optional)
• fee - specify transaction fee in satoshi (optional, otherwise fee is computed)
• note - public note to include with the transaction (optional, limit 255 characters)

URI Encoding a JSON object in JavaScript:

var myObject = { address1: 10000, address2: 50000 };
var myJSONString = JSON.stringify(myObject);
// `encodeURIComponent` is a global function
var myURIEncodedJSONString = encodeURIComponent(myJSONString);
// use `myURIEncodedJSONString` as the `recipients` parameter

Sample Response:

{
  "to" : ["1A8JiWcwvpY7tAopUkSnGuEYHmzGYfZPiq", "18fyqiZzndTxdVo7g9ouRogB4uFj86JJiy"],
  "from": ["17p49XUC2fw4Fn53WjZqYAm4APKqhNPEkY"],
  "amounts": [16000, 5400030],
  "fee": 2000,
  "txid": "f322d01ad784e5deeb25464a5781c3b20971c1863679ca506e702e3e33c18e9c",
  "success": true
}

Fetch Wallet Balance

Endpoint: /merchant/:guid/balance

Query Parameters:

• password - main wallet password (required)

Sample Response:

{ "balance": 10000 }

List Addresses

Endpoint: /merchant/:guid/list

Query Parameters:

• password - main wallet password (required)

Sample Response:

{
  "addresses": [
    {
        "balance": 79434360,
        "address": "1A8JiWcwvpY7tAopUkSnGuEYHmzGYfZPiq",
        "label": "My Wallet",
        "total_received": 453300048335
    },
    {
        "balance": 0,
        "address": "17p49XUC2fw4Fn53WjZqYAm4APKqhNPEkY",
        "total_received": 0
    }
  ]
}

Fetch Address Balance

Endpoint: /merchant/:guid/address_balance

Query Parameters:

• address - address to fetch balance for (required)
• password - main wallet password (required)

Note: unlike the hosted API, there is no option of a confirmations parameter for specifying minimum confirmations.

Sample Response:

{ "balance": 129043, "address": "19r7jAbPDtfTKQ9VJpvDzFFxCjUJFKesVZ", "total_received": 53645423 }

Generate Address

Endpoint: /merchant/:guid/new_address

Query Parameters:

• password - main wallet password (required)
• label - label to give to the address (optional)

Sample Response:

{ "address" : "18fyqiZzndTxdVo7g9ouRogB4uFj86JJiy" , "label":  "My New Address" }

Archive Address

Endpoint: /merchant/:guid/archive_address

Query Parameters:

• address - address to archive (required)
• password - main wallet password (required)

Sample Response:

{ "archived" : "18fyqiZzndTxdVo7g9ouRogB4uFj86JJiy" }

Unarchive Address

Endpoint: /merchant/:guid/unarchive_address

Query Parameters:

• address - address to unarchive (required)
• password - main wallet password (required)

Sample Response:

{ "active" : "18fyqiZzndTxdVo7g9ouRogB4uFj86JJiy" }

Installation

npm is required for installing this API service. Installation:

$ npm install -g blockchain-wallet-service

If you have issues with the installation process, see the troubleshooting section below.

Troubleshooting

If installation fails:

• If you are getting EACCESS or permissions-related errors, it might be necessary to run the install as root, using the sudo command.

Runtime errors:

• If you are getting wallet decryption errors despite having correct credentials, then it's possible that you do not have Java installed, which is required by a dependency of the my-wallet-v3 module. Not having Java installed during the npm install process can result in the inability to decrypt wallets. Download the JDK from here for Mac or by running apt-get install default-jdk on debian-based linux systems.

If this section did not help, please open a github issue or visit our support center.

Usage

After installing the service, the command blockchain-wallet-service will be available for use.

Options

• -h, --help - output usage information
• -V, --version - output the version number
• -c, --cwd - use the current directory as the wallet service module (development only)

Commands

start

Usage: blockchain-wallet-service start [options]

This command will start the service, making Blockchain Wallet API V2 available on a specified port.

Command options:

• -h, --help - output usage information
• -p, --port - port number to run the server on (defaults to 3000)
• -b, --bind - bind to a specific ip (defaults to 127.0.0.1, note that binding to an ip other than this can lead to security vulnerabilities)

To open the service to all incoming connections, bind to 0.0.0.0.

Examples

To start the Wallet API service on port 3000:

$ blockchain-wallet-service start --port 3000

Development

1. Clone this repo
2. Run npm install
3. Run npm start
4. Dev server is now running on port 3000

If you are developing blockchain-wallet-client alongside this module, it is useful to create a symlink to my-wallet-v3:

$ ln -s ../path/to/my-wallet-v3 node_modules/blockchain-wallet-client

Testing

$ npm test

Configuration

Optional parameters can be configured in a .env file:

• PORT - port number for running dev server (default: 3000)
• BIND - ip address to bind the service to (default: 127.0.0.1)

Deployment

If you want to use blockchain-wallet-service in your UNIX production server, you just have to run:

$ nohup blockchain-wallet-service start --port 3000 &