# Set up API Signer with Docker

Run a Fordefi API Signer locally with Docker desktop.

## Before you start

Make sure you complete both of these pre-steps:

- Download [Docker Desktop](https://www.docker.com/products/docker-desktop/) for your system.
- In the Fordefi console, navigate to **User Management** section and create an **API User** with the Trader role and store its access tokens securely. [Learn more](https://docs.fordefi.com/developers/getting-started/create-an-api-user).
The access token should start with `eyJhbG...` as in:



```bash
eyJhbGciOiJFZERTQSIsImtpZCI6ImZ3MFc3aVpocUc0SUEzaXV4ZmhQIiwidHlwIjoiSldUIn0.eyJpc3MiOiJodHRwczovL2FwaS5mb3JkZWZpLmNvbS8iLCJzdWIiOiJiY2M1Zjc0Zi1hN2I1LTQ0ZWEtYWM5Mi1iMzE3YzIxZjE4MjBAZm9yZGVmaSIsImF1ZCI6WyJodHRwczovL2FwaS5mb3JkZWZpLmNvbS9hcGkvIl0sImV4cCI6MjA3MTgyMzk1NSwiaWF0IjoxNzU2NDYzOTU1LCJqdGkiOiJjYzdmYmZiYi1lOTlhLTRhMjItYTMxZC0zYWYxNjJhYzQ5NGEifQ.AhSskIoXbk-9xmomj2TpH4K2_d7evIL9uGYQIb9-nQarVaydYd9aywiMfr4lFk7SbFbRRgd0HcQF7veE7JD9Cw
```

Now, set up Docker.

## Docker Setup

1. Open Docker desktop, start a new terminal and install the Fordefi API Signer image from the Fordefi artifactory ([see here](https://docs.fordefi.com/developers/getting-started/set-up-an-api-signer/install-the-api-signer)).


Password
Downloading the API Signer image will require a password. Contact Fordefi support.

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1. Before you do anything else, go back to the Fordefi console, navigate to **Settings** > **API Signer** and select **Add API Signer**, then name your signer and click **Add**.
2. Open your Fordefi mobile app - there should be an Add API signer notification in your inbox.

Open the notification and select **Activate** to start the scanner on your phone.
3. Go back to Docker, select **Provision signer** and scan the QR code that is displayed in the terminal with your Fordefi mobile app.
If the QR code doesn't fit in the Docker terminal, zoom out using `command + "minus sign"` on your keyboard.


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1. Your API Signer logs should now display the following:



```bash
YYYY-MM-DD INFO Provisioning completed successfully.

========================================
========= API-Signer Main Menu =========
========================================

Use the arrow keys to navigate: ↓ ↑ → ← 
? API-Signer is provisioned. What do you want to do?: 
  ▸ Run signer
    Register API user key
    Show API users
    Remove API user key
↓   Configure signer
```

1. On your computer, open a separate terminal and create an EC key pair as explained [here](https://docs.fordefi.com/developers/getting-started/pair-an-api-client-with-the-api-signer).


Make sure to remember where the private key is located in your system: you will need it later to make calls to the Fordefi API.

1. For now, extract the public key and make sure it's copied without the armour and in a single continuous line, without a line break, as in:



```bash
MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAED/fDkfDzZWaOZ3mEZlr7aJ5XbVh4SUJSGWPnlye3rAMYuRzYprY89rwEaXlJnLBTm6RaVV1jU0WMo+nsLN2JIw==
```

1. Then go back to Docker, select `Register API user key`, select the API user to register, and paste the public key in the field. Type `Enter` to complete the registration:


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1. Finally, select `Run signer` to start your signer.
Your signer will need to be running to sign transactions initiated by the API User you registered.


While you can only have a single API Signer per organization, you can create and pair as many API Users with your Signer as you want. To do this, simply create a new API User from the Fordefi console (see [here](https://docs.fordefi.com/developers/getting-started/create-an-api-user)), generate a new key pair for them and register the public key with the API Signer by repeating steps 5 through 7.

You're done!

To successfully transact, your API User will need to **both** authenticate with the Fordefi backend using the access token generated during its creation (see [Before you start](/developers/getting-started/set-up-an-api-signer/api-signer-docker#before-you-start) and sign  transaction payloads with the specific `private.pem` key you generated in step 5. You can learn about both steps [here](https://docs.fordefi.com/developers/authentication) and check out our [API examples](https://github.com/FordefiHQ/api-examples) for practical code examples

Also, remember that you API Signer will need to be running to sign transactions initiated by the API User you registered.