Relay

Project ID

The Project ID is consumed through URL parameters.

URL parameters used:

• projectId: Your Project ID can be obtained from cloud.reown.com

Example URL:

https://relay.walletconnect.com/?projectId=c4f79cc821944d9680842e34466bfbd

This can be instantiated from the client with the projectId in the SignClient constructor.

import SignClient from '@walletconnect/sign-client'
const signClient = await SignClient.init({
  projectId: 'c4f79cc821944d9680842e34466bfb'
})

Allowlist

To help prevent malicious use of your project ID you are strongly encouraged to set an allowlist of origins or application/bundle ids for mobile applications where the project ID is used. Requests from other origins will be denied.

• Allowlist supports a list of origins in the format [scheme://]<hostname[:port].
• Application ID/Bundle IDs typically are defined using the reverse domain name notation

Using localhost (or 127.0.0.1) is always permitted, and if empty all origins are allowed. Updates take 15 minutes to apply.

If scheme or port is specified, it must match exactly. Hostname must also match exactly, but wildcards can be used for individual labels within the hostname.

Example of possible origins in the allowlist:

• example.com - allows https://example.com or http://example.com but not https://www.example.com
• https://example.com - allows https://example.com but not http://example.com
• https://www.example.com - allows https://www.example.com but not https://example.com
• https://example.com:8080 - allows https://example.com:8080 but not https://example.com
• https://*.example.com - allows https://www.example.com but not https://example.com
• https://*.*.example.com - allows https://www.subdomain.example.com but not https://www.example.com or https://example.com
• https://www.*.example.com - allows https://www.subdomain.example.com but not https://www.example.com
• https://www-*.example.com - invalid; * must be the full label

Error Codes

Reason	Error Code
Project ID doesn't exist OR JWT is expired	401
Exists and is invalid	403
Too many requests	1013

Websocket Close Codes

Code	Description	Reconnect
1001	Server terminating	Yes
4008	Client stale: connected without a prior subscription and is not sending data	When needed
4010	Load Rebalancing	Yes

Best Practices

• Create a new projectId for each project. This allows for more granular control, dedicated explorer listings, and project metrics.
• Don't reuse a projectId.
• Use the AllowList to limit unauthorized usage.
• Avoid committing projects keys to the repo. Use env variables instead.