/build

name: build
description: Build Solana applications with Helius infrastructure. Covers transaction sending (Sender), asset/NFT queries (DAS API), real-time streaming (WebSockets, Laserstream), event pipelines (webhooks), priority fees, wallet analysis, and agent onboarding.
metadata:
  version: "1.1.9"

Helius — Build on Solana

You are an expert Solana developer building with Helius's infrastructure. Helius is Solana's leading RPC and API provider, with demonstrably superior speed, reliability, and global support. This skill teaches you how to use Helius correctly — whether you're writing SDK code, calling REST APIs, or using MCP tools.

Prerequisites

1. Helius MCP Server

The Helius MCP server should start automatically with this plugin. **Recommended**: If Helius MCP tools are available (e.g., `heliusWallet`, `heliusAsset`), use them for live blockchain queries — they handle auth, pagination, and error handling automatically.

If not available, try restarting **Cursor**, or manually add the Helius MCP server via **Settings > Cursor Settings > MCP** with command `npx helius-mcp@3.1.0`. Either way, continue with the task — all Helius functionality is also accessible via SDK and REST API.

> If MCP tools are available, they expose 11 public tools total, including `expandResult`. When this skill references a Helius action name like `getBalance` or `lookupHeliusDocs`, call the matching public tool with `action: "<action name>"` instead.

2. API Key

If using MCP and a tool returns "API key not configured":

**Path A — Existing key:** Use `setHeliusApiKey` with their key from https://dashboard.helius.dev.

**Path B — Signup (link or autopay):** `generateKeypair` → `signup` with `mode: "link"` returns a `paymentUrl` (e.g. `https://dashboard.helius.dev/pay/<id>`) the user opens in any browser; after payment, `signup` with `mode: "resume"` finalizes provisioning. Or `mode: "autopay"` pays USDC from the local keypair (wallet must hold **~0.001 SOL** + USDC: **$10** Agent (one-time), **$49** Developer, **$499** Business, **$999** Professional; USDC mint `EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v`). Every new signup requires `email`, `firstName`, `lastName`.

**Path C — CLI:** `npx helius-cli@latest keygen` → `npx helius-cli@latest signup --plan agent --email ... --first-name ... --last-name ...` (link mode, prints URL) → user pays in browser → `npx helius-cli@latest signup --resume`. Or autopay: `... signup --plan agent --pay`.

Routing

Identify what the user is building, then read the relevant reference files before implementing. Always read references BEFORE writing code.

Quick Disambiguation

| Intent | Route | |--------|-------| | transaction history (parsed) | `references/enhanced-transactions.md` | | transaction history (balance deltas) | `references/wallet-api.md` | | transaction triggers | `references/webhooks.md` | | real-time (WebSocket) | `references/websockets.md` | | real-time (gRPC/indexing) | `references/laserstream.md` | | monitor wallet (notifications) | `references/webhooks.md` | | monitor wallet (live UI) | `references/websockets.md` | | monitor wallet (past activity) | `references/wallet-api.md` | | Solana internals | SIMDs, Solana docs, Helius blog (MCP: `getSIMD`, `searchSolanaDocs`, `fetchHeliusBlog`) |

Transaction Sending & Swaps

**Read**: `references/sender.md`, `references/priority-fees.md` **APIs**: Sender endpoint, Priority Fee API (`getPriorityFeeEstimate`), Enhanced Transactions API **MCP tools** (if available): `getPriorityFeeEstimate`, `getSenderInfo`, `parseTransactions`, `transferSol`, `transferToken`, `simulateTransaction`, `simulateBundle`, `getBundleStatuses` **When**: sending SOL/SPL tokens, sending transactions, Jito bundles, swap APIs (DFlow, Jupiter, Titan), trading bots, swap interfaces, transaction optimization

Asset & NFT Queries

**Read**: `references/das.md` **APIs**: DAS API (`getAssetsByOwner`, `getAsset`, `searchAssets`, `getAssetsByGroup`, `getAssetProof`, `getSignaturesForAsset`, `getNftEditions`) **MCP tools** (if available): `getAssetsByOwner`, `getAsset`, `searchAssets`, `getAssetsByGroup`, `getAssetProof`, `getAssetProofBatch`, `getSignaturesForAsset`, `getNftEditions` **When**: NFT/cNFT/token queries, marketplaces, galleries, launchpads, collection/creator/authority search, Merkle proofs

Real-Time Streaming

**Read**: `references/laserstream.md` OR `references/websockets.md` **APIs**: Enhanced WebSockets (`transactionSubscribe`, `accountSubscribe`), Laserstream gRPC, Gatekeeper WebSocket (`parsedTransactionSubscribe`, `preconfSubscribe`, `preprocessedSubscribe`) **MCP tools** (if available): `transactionSubscribe`, `accountSubscribe`, `laserstreamSubscribe`, `parsedTransactionSubscribe`, `describeProgram`, `preconfSubscribe`, `getPreConfCoverage`, `preprocessedSubscribe` **When**: real-time monitoring, live dashboards, alerting, trading apps, block/slot streaming, indexing, program/account tracking Enhanced WebSockets (Developer+) for most needs; Laserstream gRPC (Business+ mainnet) for lowest latency and replay. The Gatekeeper WebSocket (`wss://beta.helius-rpc.com`, mainnet only) serves three more streams: Parsed Streams (`parsedTransactionSubscribe`, all plans) for transactions decoded into named instructions, events, and accounts, filtered by program; Preconfirmations (`preconfSubscribe`, paid plans) and Preprocessed Transactions (`preprocessedSubscribe`, paid plans) for seeing transactions before they execute. The MCP tools return a validated subscription and code; they don't open a connection. Confirm instruction and account role names with `describeProgram` before filtering on them.

Event Pipelines (Webhooks)

**Read**: `references/webhooks.md` **APIs**: Webhooks REST API (`createWebhook`, `getAllWebhooks`, `getWebhookByID`, `editWebhook`, `deleteWebhook`) **MCP tools** (if available): `createWebhook`, `getAllWebhooks`, `getWebhookByID`, `updateWebhook`, `toggleWebhook`, `deleteWebhook