Developer Integration

Send blockchain-native emails from smart contracts, AI agents, and applications

Quick Reference

Contract:outlayer.near

Project ID:zavodil.near/near-email

API Base:api.outlayer.fastnear.com

Address space:alice.near = alice@near.email

Use Cases

NFT Marketplace

Notify users when their NFT is sold

DeFi Protocol

Alert users about liquidation risk

DAO Governance

Send voting reminders and proposal notifications

AI Agents

Enable agents to communicate via email

Integration Methods

Method	Best For	Payment
Smart Contract (Rust)	On-chain notifications	Deposit (unused refunded)
Payment Key (HTTPS)	Server-side agents, high volume	Pre-paid balance (USDC)
NEAR Transaction	Browser wallets, direct signing	Deposit (unused refunded)

1. Smart Contract Integration (Rust)

Smart contracts send emails by calling OutLayer's request_execution method.

Warning:Email content (to, subject, body) is stored publicly on the NEAR blockchain. Use send_email_plaintext only for automated notifications.

2. Payment Key (HTTPS API)

Pre-fund a payment key and make simple HTTPS calls. Best for server-side agents.

Setup Steps

1Go to OutLayer Dashboard → Payment Keys
2Create a new key and add USD balance
3Copy the key (format: owner:nonce:secret)

Privacy:Use send_email with ECIES encryption for private emails — only the recipient can decrypt. Examples below use send_email_plaintext for simplicity (content is public on-chain).

3. NEAR Transaction (Per-Use)

Sign transactions directly with NEAR wallet. Attach deposit as a limit for computation costs — unused portion is automatically refunded.

Critical:NEAR Transaction results are in the outlayer.near receipt's SuccessValue (base64-encoded JSON). Find the receipt where executor_id === 'outlayer.near'. Returns { "success": true, ... } directly — NO output wrapper!

Privacy:Use send_email with ECIES encryption for private emails — only the recipient can decrypt. Examples below use send_email_plaintext for simplicity (content is public on-chain).

API Actions

Action	Description	Encryption
send_email_plaintext	Send email (PUBLIC on-chain)	None
send_email	Send email (private, only recipient decrypts)	ECIES
get_emails	Fetch inbox and sent emails	ECIES
delete_email	Delete email by ID	ECIES
get_email_count	Get inbox/sent counts	None
get_send_pubkey	Get sender's pubkey for encryption	None

Limits

Limit	Transaction Mode	Payment Key Mode
Max response size	1.5 MB	25 MB
Max file per attachment	5 MB	5 MB
Max total email size	7 MB	7 MB
Max attachments per email	10	10

Resource Limits (for NEAR Transactions)

When calling via NEAR transaction, use these resource limits:

{
  "max_memory_mb": 512,
  "max_instructions": 2000000000,
  "max_execution_seconds": 120
}