API reference

RelayGuard exposes standard EVM JSON-RPC over HTTPS. Workspace and environment are resolved from your API key — not from the URL path.

Base URL

https://gateway.0xrelayguard.com

Authentication

Send your API key on every request. For apps and server-side code, prefer a header:

Authorization: Bearer rg_live_...

Or:

X-RelayGuard-Key: rg_live_...

For tools that only accept an RPC URL (Foundry Cast, some Hardhat configs), append the key as a query parameter:

https://gateway.0xrelayguard.com/rpc/ethereum?key=rg_live_...

URL-based keys are convenient for local dev but may appear in proxy logs and shell history. Use Bearer auth in production services.

JSON-RPC

POST /rpc/:chain
Content-Type: application/json

{
  "jsonrpc": "2.0",
  "method": "eth_blockNumber",
  "params": [],
  "id": 1
}

Supported chains (beta): ethereum, polygon, arbitrum, base, optimism.

Failover: eligible read methods may retry on another healthy provider. eth_sendRawTransaction is never automatically retried.

Security Mode

Use POST /rpc/:chain for all traffic. When Security Mode is enabled, methods in your dashboard policy automatically require quorum; other methods route normally. See Security Mode.

Status

GET /status
Authorization: Bearer rg_live_...

Returns runtime mode, provider health, block lag, and last check times for your workspace.

Error responses

• 401 unauthorized — missing or invalid API key
• 429 rate_limited — per-key rate limit exceeded
• 503 no providers configured — add providers in the dashboard
• 503 no healthy providers available — all providers failing or lagging