Send notifications to your users.
Never touch their data.

One API call. Full compliance. Built-in privacy. Herald handles the email and SMS delivery, while ensuring your database stays clean of sensitive PII.

Get early access →

Storing emails is a liability mistake.

The Legacy Flow

PII Mapping

You write a mapping of public keys to plaintext emails in your database.

Compliance Burden

You are now fully responsible for GDPR, user deletion requests, and opt-outs.

High-Value Target

Your database becomes a lucrative target for phishing attacks and exploits.

The Protocol Way

Zero State

You only ever handle the user's on-chain public key. No database updates required.

Compliance by Design

Herald's TEE architecture handles the encryption so you never touch regulated data.

Cryptographic Proof

Every dispatched message results in a verifiable, zero-knowledge receipt on Solana.

Integration Simplicity

One API call. Five minutes to ship.

Developer experience

Integrate in minutes,
not days.

Our SDK handles the complex encryption, on-chain identity resolution, and ZK receipt writing. You just call notify().

TypeScript, Rust, and REST API — all first-class
Automatic retry with exponential backoff
Full TypeScript types auto-generated from OpenAPI
View quickstart
SDK reference
import { Herald } from '@herald-protocol/sdk';


const herald = new Herald({
  apiKey: process.env.HERALD_API_KEY, // hrld_live_xxx
});


// Send a DeFi alert — no email needed
const result = await herald.notify({
  wallet: '7xR4mKp2nQ...', // Recipient's Solana address
  subject: 'Liquidation Warning — Action Required',
  body: 'Your health factor on Drift is 1.05. Add collateral.',
  category: 'defi',
  receipt: true,         // Write on-chain proof
  idempotencyKey: `liq_${userId}_${Date.now()}`,
});


// { notificationId, status: 'queued', receiptTx: null }
ready

Use cases

Versatile APIs
for any protocol.

Email, Telegram, and SMS — no matter what you're building.

DEFI

Liquidation Warnings

Alert users when their health factor drops below a critical threshold to prevent unwinding.

DAO

Governance Reminders

Notify token holders about active DAO proposals requiring their attention and vote.

YIELD

Position Updates

Send daily wrap-ups, claimable rewards, and significant lending position changes.

SECURITY

Security Alerts

Instantly broadcast emergency protocol pauses or action-required security updates.

VAULTS

Yield Changes

Notify liquidity providers when vault APYs spike or drop significantly.

NFT

NFT Infrastructure

Send whitelist claim reminders, mint phase transitions, and drop announcements out-of-band.

Pricing

Start free. Pay in USDC when you scale.

No credit card required. Pay with any Solana wallet via native USDC streaming.

Developer
$0/mo

For building and testing your integration.

1,000
sends / month
—
no overage on free tier

Email delivery, sandbox & ZK receipts included.

Get early access
GrowthMost popular
$99/mo

For protocols with an active user base.

50,000
sends / month
$0.002
/ send over limit

Everything in Developer, plus more channels, seats & SLA.

Get early access
Scale
$299/mo

For high-volume protocols and growing teams.

250,000
sends / month
$0.0015
/ send over limit

Everything in Growth, plus more channels, seats & SLA.

Get early access
Enterprise
Custom

Custom volume, SLAs, and dedicated support.

1M+
sends / month
Custom
volume-based rate

Everything in Scale, plus more channels, seats & SLA.

Get early access

All tiers include ZK receipts · No hidden fees · Cancel anytime

Pay with USDC via any Solana wallet — view full pricing details →

Your first notification is one install away

Install the SDK, call notify(), and Herald handles encryption, on-chain resolution, and delivery.

$npm i @herald-protocol/sdk
Get early access →Read the quickstart