Using POST in d3-json by fil

d3-fetch uses the Javascript API Fetch, and can pass arguments along.

index.html

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <script src="https://unpkg.com/d3-fetch"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
  </style>
</head>

<body>
  <script>
    // Feel free to change or delete any of the code you see in this editor!
    var svg = d3.select("body").append("svg")
      .attr("width", 960)
      .attr("height", 500)

    d3.json('https://jsonplaceholder.typicode.com/posts', {
      method:"POST",
      body: JSON.stringify({
        title: 'Hello',
        body: '_d3-fetch_ is it',
        userId: 1,
        friends: [2,3,4]
      }),
      headers: {
        "Content-type": "application/json; charset=UTF-8"
      }
    })
    .then(json => {
     svg.append("text")
      .text(JSON.stringify(json))
      .attr("y", 200)
      .attr("x", 120)
      .attr("font-size", 16)
      .attr("font-family", "monospace")
      
    });

  </script>
</body>