Developer documentation

Speedy RPC is in early access. Items marked coming soon are not available yet.

1. What Speedy RPC is

Speedy RPC is an RPC gateway for Polkadot-ecosystem chains, run from Sydney, Australia, behind Cloudflare. You don't run your own node: one API key works on both HTTPS (JSON-RPC requests) and WebSocket (WSS, for subscriptions such as new blocks). Every key has published rate limits.

What you can build

• Wallets, explorers and dashboards that read balances, blocks and storage over HTTPS, and follow new blocks over WSS.
• dApps and back ends on Polkadot and Astar with polkadot.js or PAPI (Substrate JSON-RPC).
• EVM apps on Astar (chain ID 592) with ethers, viem or Foundry cast.

2. Networks and endpoints

2.1 How the API key is passed

• Content type: application/json, JSON-RPC 2.0 body.
• Keys start with sk_. Keys are stored hashed and shown once when issued, so save yours somewhere safe.
• Health check (no key needed): GET https://api.speedyrpc.io/healthz returns ok.

2.2 Production endpoints (api.speedyrpc.io)

• app.speedyrpc.io serves the portal; apps should use api.speedyrpc.io.
• Coming soon: Polkadot Asset Hub and more parachains, archive (historical-state) access, Astar EVM over WSS, browser CORS policy, SLA and status page.

3. Getting a key

Email support@speedyrpc.io with your project, the networks you need and your expected traffic. We reply with a key on the right tier. Self-serve sign-up and billing are coming soon.

Tiers and limits

Limits apply per API key and are enforced by the gateway. Going over a limit returns HTTP 429; requests are never silently dropped.

Pricing will be announced when billing opens (coming soon).

4. Quick start

SPEEDY_KEY is an environment variable holding your key. Never commit keys to a repository or paste them into issues or chat.

export SPEEDY_KEY="sk_..."

4.1 curl (HTTPS JSON-RPC)

curl https://api.speedyrpc.io/rpc/polkadot \
  -H "X-API-Key: $SPEEDY_KEY" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"system_chain","params":[]}'
# -> {"jsonrpc":"2.0","id":1,"result":"Polkadot"}

Astar EVM:

curl https://api.speedyrpc.io/rpc/astar-evm \
  -H "X-API-Key: $SPEEDY_KEY" -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}'
# -> "result":"0x250"  (592)

4.2 polkadot.js (WSS)

import { ApiPromise, WsProvider } from '@polkadot/api';

const url = `wss://api.speedyrpc.io/ws/polkadot?api_key=${process.env.SPEEDY_KEY}`;
const api = await ApiPromise.create({ provider: new WsProvider(url) });

console.log('Chain:', (await api.rpc.system.chain()).toString());
const unsub = await api.rpc.chain.subscribeNewHeads((h) => {
  console.log('New block #', h.number.toNumber());
});

4.3 PAPI (polkadot-api)

import { createClient } from 'polkadot-api';
import { getWsProvider } from 'polkadot-api/ws-provider/node'; // path may differ by PAPI version

const client = createClient(
  getWsProvider(`wss://api.speedyrpc.io/ws/polkadot?api_key=${process.env.SPEEDY_KEY}`)
);

const spec = await client.getChainSpecData();
console.log('Chain:', spec.name);
client.finalizedBlock$.subscribe((b) => console.log('Finalized #', b.number));

For typed calls, generate descriptors with npx papi add against the same URL.

4.4 ethers (v6): Astar EVM

import { ethers } from 'ethers';

const req = new ethers.FetchRequest('https://api.speedyrpc.io/rpc/astar-evm');
req.setHeader('X-API-Key', process.env.SPEEDY_KEY);
const provider = new ethers.JsonRpcProvider(req, 592, { staticNetwork: true });

console.log(await provider.getBlockNumber());

Foundry:

cast chain-id --rpc-url https://api.speedyrpc.io/rpc/astar-evm --rpc-headers "X-API-Key: $SPEEDY_KEY"
# -> 592

5. Errors

6. Support

• Email: support@speedyrpc.io (key requests, limits, new networks, problems).
• Include: network id, approximate time (with time zone), HTTP status and response body, and only your key prefix (never the full key).
• Status page and published support hours: coming soon.

7. Coretime (coming soon)

A Coretime secondary marketplace (trading Polkadot coretime regions after the primary sale) is currently running on testnet only. It is not available on production yet; mainnet availability is coming soon.