Multichain API is available on every plan, including Developer.
What is a multichain endpoint?
A multichain endpoint is a named group of your existing nodes with one shared API key. The key authorizes requests to each node in the group, so you can put a single secret in your environment variables or CI instead of one per chain. Your nodes, their own endpoint URLs, and their own API keys stay as they are. An endpoint can hold the following:- One Global Node per protocol and network
- Any number of Dedicated Nodes
Create an endpoint
1
Open Multichain API
On Chainstack, click Multichain API in the left menu.
2
Name the endpoint
Click Create endpoint, enter a name, and click Create endpoint again. The name is up to 30 characters. Chainstack opens the new endpoint’s page, which shows the API key.
The endpoint appears in the Multichain API list with a masked API key.


Add nodes to an endpoint
1
Open the endpoint
On Chainstack, click Multichain API and click the endpoint name.
2
Add the nodes
In Connected nodes, click Add node. Search for a node by name, or filter the list by type (Global or Dedicated), and click Add next to each node you want. Click Done when finished.
The nodes appear in Connected nodes, and each one is listed in the Node selector under Connection details.

Call a chain with the key
Each attached node has its own URL on the endpoint page. To get it, open the endpoint, select a node in Connection details, and copy the HTTPS endpoint or the WSS endpoint. The key is already part of the URL. For a Global Node, the URL uses thecore.chainstack.com host with the chain and network in the subdomain. A Dedicated Node uses its own host, so copy the URL from Connection details instead of building it yourself.
The following example sends the same request to an attached Ethereum Mainnet Global Node and an attached Solana Mainnet Global Node with one key:
cURL
YOUR_MULTICHAIN_API_KEY with the key from your endpoint page. Each call returns a normal JSON-RPC result for its chain.
A request to an attached chain returns a valid response. A request to a chain that isn’t attached returns
401 Unauthorized.How requests are handled
- Requests to a chain follow the node behind it — the rate limits and access rules you set on that node apply.
- A request with the key to a chain whose node isn’t attached to the endpoint returns
401 Unauthorized. - When you delete a node on Chainstack, the node is removed from its endpoints automatically. The endpoint and its key stay.
- Removing the last node from an endpoint leaves the endpoint and its key in place with no nodes.
- A node that isn’t running has no connection details until it runs again.
Find the API key
Open the endpoint on the Multichain API page. The full key is under API key, and Copy puts it on your clipboard. The key starts withmt_ and is always available on the endpoint page. The list shows a shortened key, and its copy button copies the full value.
Treat the key as a secret. See Best practices for securing your Chainstack endpoint for guidance.
Replace an API key
An endpoint’s key can’t be rotated. To replace a key, for example after it leaks:1
Create a new endpoint
Create an endpoint and add the same nodes to it.
2
Update your applications
Switch your environment variables or CI secrets to the new key.
3
Delete the old endpoint
Open the old endpoint and delete it, as described in the next section.
Remove a node or delete an endpoint
To remove a node from an endpoint, open the endpoint, and click the trash icon next to the node in Connected nodes. Requests to that chain with the key return401 Unauthorized, and the other chains keep working.
To delete an endpoint, click Delete endpoint on its page, or click the trash icon in its row on the Multichain API list. The confirmation shows how many nodes the key stops working on. After you click Yes, I’m sure, the key stops working on every attached node. This action can’t be undone, and your nodes are not deleted.