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Authentication

EthGasStation API v1 uses an API key header, not a bearer token.

Header format​

x-api-key: <your_api_key>

How to get a key​

Create keys in the signed-in app:

  1. Open Developer
  2. Open API & MCP Console
  3. Create a named key
  4. Copy the full key immediately

Key handling guidance​

  • store keys in a secret manager or deployment environment, not source control
  • rotate keys when an integration changes ownership or a credential may have leaked
  • revoke keys you no longer need
  • prefer one key per integration or service owner

Example request​

curl -s https://ethgasstation.io/be/api/v1/gas/current \
  -H "x-api-key: $EGS_API_KEY" \
  -H "Accept: application/json"

MCP is different​

AI Connect / MCP does not use x-api-key in its normal production flow. MCP uses OAuth and bearer tokens for user-scoped access.

Use API keys for server-side integrations and testing. Use OAuth for MCP clients.

Requests without a valid API key return 401 Unauthorized.