09 Building Hateoas Clients

title: Building HATEOAS Clients for Hypermedia APIs weight: 19 date: 2026-06-28 lastmod: 2026-06-28 description: Build HATEOAS clients that navigate APIs by following hypermedia links, discover available actions, and handle state transitions without hard-coded endpoint URLs. tags: [api-development, hateoas]

HATEOAS clients navigate APIs dynamically by starting at a root URL, discovering links via rel values, and following them based on semantic meaning rather than URL construction.

```python
import requests

class HATEOASClient:
    def __init__(self, root_url):
        self.root_url = root_url
        self.current = self._get(root_url)

    def _get(self, url):
        response = requests.get(url)
        response.raise_for_status()
        return response.json()

    def follow(self, rel):
        """Follow a link by its relationship name."""
        links = self.current.get("_links", {})
        if rel not in links:
            raise KeyError(f"No link with rel '{rel}' found")
        href = links[rel]["href"]
        self.current = self._get(href)
        return self.current

    def get_available_actions(self):
        """List all available actions."""
        return list(self.current.get("_links", {}).keys())

# Usage
client = HATEOASClient("https://api.example.com/api")
print(f"Available: {client.get_available_actions()}")
user = client.follow("users")
print(f"Users: {user}")

What's Next

Now learn about HATEOAS design patterns in Hypermedia APIs and HATEOAS.