Developer onboarding

A Blaze app starts with a provider and wallet. Blaze.from combines them. newTransaction creates a builder with the provider's network and parameters, then adds wallet inputs when the transaction is completed.

Install the SDK

bun add @blaze-cardano/sdk

The SDK re-exports the query providers, transaction builder, wallet types, and core Cardano types used in most applications.

Pick a provider

Use Blockfrost, Maestro, or Kupmios when talking to a real network. Use RoutedProvider when different backends should handle reads, evaluation, and submission.

import { Blockfrost, Maestro, RoutedProvider } from "@blaze-cardano/sdk";

const queryProvider = new Blockfrost({
  network: "cardano-preview",
  projectId: process.env.BLOCKFROST_PROJECT_ID!,
});

const submissionProvider = new Maestro({
  network: "preview",
  apiKey: process.env.MAESTRO_API_KEY!,
});

const provider = new RoutedProvider({
  defaultProvider: queryProvider,
  queryProvider,
  evaluationProvider: submissionProvider,
  submissionProvider,
});

The query package provider guides describe provider internals and network requests.

Build and submit a payment

Blaze.from binds a provider and wallet. newTransaction returns a transaction builder with the provider parameters already available.

import { Blaze, Core, HotWallet } from "@blaze-cardano/sdk";

const masterKey = process.env.WALLET_MASTER_KEY;
if (!masterKey) throw new Error("WALLET_MASTER_KEY is required");

const wallet = await HotWallet.fromMasterkey(
  Core.Bip32PrivateKeyHex(masterKey),
  provider,
);
const blaze = await Blaze.from(provider, wallet);
const receiver = Core.Address.fromBech32("addr_test...");

const tx = await blaze
  .newTransaction()
  .payLovelace(receiver, 5_000_000n)
  .complete();

const signed = await blaze.signTransaction(tx);
await blaze.submitTransaction(signed, true);

Query chain state

Provider methods return core Cardano objects rather than JSON transport payloads.

const utxos = await provider.getUnspentOutputs(wallet.address);
const params = await provider.getParameters();
const slotConfig = provider.getSlotConfig();

console.log(utxos.length, params.minFeeCoefficient, slotConfig.slotLength);

Build with an Aiken validator

The Blueprint package turns Aiken's plutus.json into generated TypedScript classes. The Blueprint guide covers generation, validator parameters, typed datums and redeemers, attached scripts, and reference inputs. The Aiken contract tutorial follows a complete local transaction flow.

Run the example workspace to compile its validator, regenerate plutus.ts, deploy a reference script, lock an inline datum, query the script UTxO, and spend it through the emulator:

bun install
bun --filter script-deploy-aiken start

Provider checklist

Check the provider setup before connecting it to a UI or service:

• One backend can handle every operation through Blockfrost, Maestro, or Kupmios directly.
• RoutedProvider can send reads, evaluation, and submission to different backends.
• Per-operation routing can send an individual query to a specific backend.
• Route debug logs may contain addresses, transaction bodies, or provider parameters. Enable them only while investigating a problem and redact them before storing the output.

The query package guides cover the provider network requests and the routing/debug event shape in more detail.