Step 1: Initial Request (to get Macaroon and Invoice)

First, make a request to the API with your desired image parameters. This initial request will not generate the image yet; instead, it will return a 402 Payment Required status along with the L402 headers (a macaroon and a Lightning invoice).

Example `curl` command:

curl -X POST https://sats4ai.com/api/l402/image \
-H "Content-Type: application/json" \
-d '{
  "input": {
    "prompt": "A futuristic cityscape at sunset, neon lights reflecting on wet streets",
    "width": 1024,
    "height": 1024
  },
  "model": "Best"
}' \
-i

Explanation of the command:

• -X POST: Specifies an HTTP POST request.
• https://sats4ai.com/api/l402/image: The target API URL.
• -H "Content-Type: application/json": Indicates the request body is JSON.
• -d '{...}': The JSON data payload with your image preferences.
• -i: Tells `curl` to include HTTP response headers in the output (so you can see the www-authenticate header).

Expected Response Headers:

You will receive an HTTP/1.1 402 Payment Required response. Look for the www-authenticate header:

www-authenticate: L402 macaroon="<YOUR_MACAROON_STRING_HERE>", invoice="<YOUR_LIGHTNING_INVOICE_HERE>"

• <YOUR_MACAROON_STRING_HERE>: This is your unique access token (the "ticket").
• <YOUR_LIGHTNING_INVOICE_HERE>: This is the Lightning Network invoice you need to pay.

Step 2: Pay the Lightning Invoice

Copy the <YOUR_LIGHTNING_INVOICE_HERE> string and pay it using any Lightning-enabled Bitcoin wallet. Upon successful payment, your wallet will provide you with a preimage. The preimage is your cryptographic proof of payment.

Step 3: Final Request (to get the Image)

Once you have the macaroon (from Step 1) and the preimage (from Step 2), make the exact same POST request again. This time, include an Authorization header.

Important: The JSON data payload (-d '{...}') in this second request must be identical to the one sent in Step 1.

Example `curl` command:

curl -X POST https://sats4ai.com/api/l402/image \
-H "Content-Type: application/json" \
-H "Authorization: L402 <YOUR_MACAROON_STRING_HERE>:<YOUR_PREIMAGE_HERE>" \
-d '{
  "input": {
    "prompt": "A futuristic cityscape at sunset, neon lights reflecting on wet streets",
    "width": 1024,
    "height": 1024
  },
  "model": "Best"
}'

Explanation of changes:

• Replace <YOUR_MACAROON_STRING_HERE> with the actual macaroon from Step 1.
• Replace <YOUR_PREIMAGE_HERE> with the actual preimage from Step 2.
• The -H "Authorization: L402 <macaroon>:<preimage>" header is added.

Expected Successful Response:

If the L402 authentication is valid, the API will process your request and return the generated image as a base64 encoded string:

data:image/jpeg;base64,... (long base64 string representing the image)

You can then decode this base64 string to get your image file.

Request Body Parameters

Here's a breakdown of the JSON object you send in your POST request body: