What is a Harmony Devnet Shard 1 RPC?
An RPC endpoint connects wallets and applications to Harmony Devnet Shard 1. Use the endpoints above for JSON-RPC requests, and keep alternatives available for regional endpoint failures or rate limits.
testnetChain ID 1666900001 · ONE
Harmony Devnet Shard 1
Public RPC endpoints and wallet configuration for Harmony Devnet Shard 1.
Network endpoints
Add Harmony Devnet Shard 1 to MetaMask
Use “Add to wallet” to request the network configuration. Always verify chain ID 1666900001, currency ONE, and the selected RPC before approving.
Public RPC safety
Public endpoints are third-party infrastructure. They may log requests, enforce limits, or become unavailable. Never place private keys, seed phrases, or secrets in an RPC request.
Common RPC errors
Rate limits, browser CORS rules, network mismatch, and temporary provider failures are common. Try another listed endpoint and verify the returned chain ID.
Harmony Devnet Shard 1 RPC FAQ
What is the RPC URL for Harmony Devnet Shard 1?+
https://api.s1.ps.hmny.io is the recommended endpoint in this directory. Multiple alternatives are listed above in case an endpoint is unavailable from your region.
What is the Harmony Devnet Shard 1 chain ID?+
Harmony Devnet Shard 1 uses chain ID 1666900001 (0x635ae021 in hexadecimal).
How do I add Harmony Devnet Shard 1 to my wallet?+
Use the Add to wallet button above. Your wallet will ask you to review and approve the network details.
Are public RPC endpoints safe?+
Treat public RPCs as infrastructure operated by third parties. They can observe requests, rate-limit traffic, or be unavailable. Never send private keys or seed phrases to an RPC.
Found an issue?
Report a broken RPC →Help keep network data current through a community contribution.