There are 3 primary developer tools for using the Blockchain API:
 
1. Unified API - enterprise-grade endpoints to use with any programming language. Switch blockchains with one path parameter.

curl -X GET https://api.covalenthq.com/v1/eth-mainnet/events/address/0x5FF137D4b0FDCD49DcA30c7CF57E578a026d2789/\?starting-block\=19570500\&ending-block\=latest \
    -H 'Content-Type: application/json' \
    -u YOUR_API_KEY:

 
2. Client SDKs - official client libraries for TypeScript, Go and Python.
 

import { CovalentClient } from "@covalenthq/client-sdk";

(async () => {
   const client = new CovalentClient("YOUR_API_KEY");
   try {
      for await (const resp of client.BaseService.getLogEventsByAddress("eth-mainnet","0x5FF137D4b0FDCD49DcA30c7CF57E578a026d2789", {"startingBlock": 19570500, "endingBlock": "latest"})) {
    console.log(resp);
  }
} catch (error) {
    console.log(error.message);
}
})();

 
3. GoldRush Kit - beautifully designed React components for your dApp frontend

See the following links to our API Docs and Guides:
- API Docs: comprehensive knowledge base for all things Covalent
- Guides: learn how to build for various use cases and expand your onchain knowledge