Waldo is Center's NFT indexer robot. It's in charge of fetching NFT metadata and media.

We obsess over our indexer -- and have rebuilt it several times from the ground-up. Waldo is the product of all of this hard work and allows us to deliver pristine data quality to our users. Waldo has several key advantages compared to traditional indexers:

1. Waldo is smart and proactive: Our systems detect automatically if there are gaps in data – and proactively fetch the missing data before we even notice it's missing.
2. Waldo is flexible: We can index new types of NFTs and media, even if we haven't seen them before or explicitly added support for them. Our indexer adapts automatically, without requiring any manual oversight.
3. Waldo has a long memory: We automatically detect and log all versions of NFT metadata, which means we know when assets reveal and always serve the latest data.

Technical details

User Agent

When Waldo makes requests, they will specify the following user agent:

• User agent token: Center-Waldo/1.0 (+https://center.dev/waldo)

IP Addresses

Requests will originate from the following IP addresses:

• 34.110.128.4
• 34.111.159.210
• 34.111.236.159
• 34.149.190.39

Getting the IP Addresses Programmatically

This IP range may change in the future. To periodically refresh the IP and User-Agent list, visit:

https://center.dev/waldo.json

The file will look like this:

{
  "addresses": [
    "34.110.128.4",
    "34.111.159.210",
    "34.111.236.159",
    "34.149.190.39"
  ],
  "userAgents": ["Center-Waldo/1.0 (+https://center.dev/waldo)"]
}