L402 Convert File API

L402 API

Pay with Bitcoin, get AI results. Copy-paste the commands below.

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Before You Start

Lightning Wallet

Phoenix, Muun, Wallet of Satoshi, Alby, or any LN wallet. Agents: CLW

Terminal or Tool

A command line, Postman, or lnget (recommended)

Private & No Signup

No account, no subscription, no personal data. Pay only when you use it

Want to try this without a terminal? Use File Conversion on the web — pay with any Lightning wallet, no setup needed.

Using the L402 File Conversion API

Convert files between formats (e.g. DOCX to PDF, PNG to WEBP). Powered by CloudConvert.

API Endpoint: https://sats4ai.com/api/l402/convert-file

Step 1: Initial Request

Send the file (base64-encoded) with source and target formats. You will receive a 402 Payment Required response.

curl -X POST https://sats4ai.com/api/l402/convert-file \
-H "Content-Type: application/json" \
-d '{
  "file": "<base64-encoded-file-data>",
  "file_name": "document.docx",
  "extensionFrom": "docx",
  "extensionTo": "pdf"
}' \
-i

Expected Response Headers:

www-authenticate: L402 macaroon="<YOUR_MACAROON>", invoice="<LIGHTNING_INVOICE>"

Step 2: Pay the Lightning Invoice

Pay the invoice and save the preimage.

Step 3: Final Request

Send the exact same request with the Authorization header.

Important: The JSON payload must be identical to Step 1.

curl -X POST https://sats4ai.com/api/l402/convert-file \
-H "Content-Type: application/json" \
-H "Authorization: L402 <YOUR_MACAROON_STRING_HERE>:<YOUR_PREIMAGE_HERE>" \
-d '{
  "file": "<base64-encoded-file-data>",
  "file_name": "document.docx",
  "extensionFrom": "docx",
  "extensionTo": "pdf"
}'

Expected Successful Response:

{ "url": "https://..." }

The returned URL is a temporary download link for the converted file.

Request Body Parameters

`file`: string (required)

Base64-encoded file data. Can include a data URI prefix (it will be stripped automatically).

`file_name`: string (required)

Original file name (e.g. "document.docx").

`extensionFrom`: string (required)

Source file format (e.g. "docx", "png", "mp4").

`extensionTo`: string (required)

Target file format (e.g. "pdf", "webp", "mp3").