How to Access Polkadot via Substrate RPC API

Step 1: To access Polkadot via Substrate RPC, use the native access endpoint with /http-rpc at the end:

Network: Polkadot Mainnet
Request Type: POST

https://svc.blockdaemon.com/polkadot/mainnet/native/http-rpc

Network: Polkadot Westend
Request Type: POST

https://svc.blockdaemon.com/polkadot/westend/native/http-rpc

Step 2: You should authorize your request. Learn more: Authentication Guide

Step 3: Specify a Substrate RPC method in the request body:

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

Example Request for Substrate RPC API

Here is a cURL example for using system_syncState to get the chainspec running the node, with a sync state, in Polkadot Mainnet:

curl -X POST \
https://svc.blockdaemon.com/polkadot/mainnet/native/http-rpc \
-H 'Authorization: Bearer YOUR_API_KEY' \
-H 'Content-Type: application/json' \
-d '{"jsonrpc": "2.0", "id": 1, "method": "system_syncState", "params": []}'

The following is a typical response you will get:

{
    "jsonrpc": "2.0",
    "result": {
        "startingBlock": 11614877,
        "currentBlock": 11615160
    },
    "id": 1
}

Example Request for Substrate RPC API

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