This post goes over how to fetch Amplitude taxonomy event properties with JavaScript.

Keys

Find your keys in Organization settings > Projects:

• API Key
• Secret Key

Credentails

Create a script:

touch fetch-amplitude.js

Encode your credentials with base64:

// fetch-amplitude.js
const apiKey = '1234567890abcdef1234567890abcdef';
const secretKey = 'abcdef1234567890abcdef1234567890';

const credentials = Buffer.from(`${apiKey}:${secretKey}`, 'utf8').toString(
  'base64',
);

Authentication

Make a GET request with your credentials:

// fetch-amplitude.js
// ...
const url = 'https://amplitude.com/api/2/taxonomy/event-property';

const response = fetch(url, {
  headers: {
    Authorization: `Basic ${credentials}`,
    'Content-Type': 'application/x-www-form-urlencoded',
  },
});

response.then((body) => body.json()).then((data) => console.log(data));

Verify that the response is successful:

node fetch-amplitude.js

If a key is invalid, you’ll get the error:

{
  "error": {
    "http_code": 403,
    "type": "unspecified",
    "message": "Unspecified Error",
    "metadata": { "details": "Invalid API Key" }
  }
}

Params

Pass the event_type as a query string parameter:

// fetch-amplitude.js
// ...
const params = new URLSearchParams({
  event_type: '[Amplitude] Page Viewed',
});

const response = fetch(url + '?' + params.toString(), {
  headers: {
    Authorization: `Basic ${credentials}`,
    'Content-Type': 'application/x-www-form-urlencoded',
  },
});
// ...

Note that the url will look like:

https://amplitude.com/api/2/taxonomy/event-property?event_type=%5BAmplitude%5D+Page+Viewed

If it worked, then you should see the following:

{ "success": true, "data": [] }

If your event has properties, you’ll see something like:

{
  "success": true,
  "data": [
    {
      "event_property": "label",
      "event_type": "[Amplitude] Page Viewed",
      "description": "Some description",
      "type": "string",
      "regex": null,
      "enum_values": null,
      "is_array_type": false,
      "is_required": true
    }
  ]
}

Script

Here’s the full script:

// fetch-amplitude.js
const apiKey = '1234567890abcdef1234567890abcdef';
const secretKey = 'abcdef1234567890abcdef1234567890';

const credentials = Buffer.from(`${apiKey}:${secretKey}`, 'utf8').toString(
  'base64',
);

const url = new URL('https://amplitude.com/api/2/taxonomy/event-property');
url.searchParams.append('event_type', '[Amplitude] Page Viewed');

const response = fetch(url.toString(), {
  headers: {
    Authorization: `Basic ${credentials}`,
    'Content-Type': 'application/x-www-form-urlencoded',
  },
});

response.then((body) => body.json()).then((data) => console.log(data));