Sign Typed Data

Use namera.sign() with type: "typed-data" for EIP-712 payloads. The domain, types, primary type, and message together define what is signed.

Before You StartCopy Anchor Link

Use an authenticated client and a session key installed on Base Sepolia with signature authority. Its API signature policy must allow typed-data and match any configured domain rules.

npm install @namera-ai/sdk

Define the PayloadCopy Anchor Link

This example signs a Greeting for your application. Replace the verifying contract with your application's contract on Base Sepolia, and use the domain and types expected by that application.

import { NameraClient, type EvmTypedData } from "@namera-ai/sdk";

const namera = new NameraClient({ apiKey: process.env.NAMERA_API_KEY! });

const typedData = {
  domain: {
    name: "Namera Example",
    version: "1",
    chainId: 84532,
    verifyingContract: "0x3333333333333333333333333333333333333333",
  },
  types: {
    Greeting: [{ name: "contents", type: "string" }],
  },
  primaryType: "Greeting",
  message: { contents: "Hello from Namera" },
} satisfies EvmTypedData;

The domain uses the numeric chain ID 84532. The SDK request uses the network identifier eip155:84532.

Sign the PayloadCopy Anchor Link

Replace the account and session-key IDs with your own:

const signed = await namera.sign({
  namespace: "eip155",
  walletId: "0199dfe1-0000-7000-8000-000000000001",
  sessionKeyId: "0199dfe1-0000-7000-8000-000000000002",
  chainId: "eip155:84532",
  type: "typed-data",
  typedData,
});

if (!signed.success) throw new Error(signed.error.message);

console.log(signed.data);

{
  "namespace": "eip155",
  "walletId": "0199dfe1-0000-7000-8000-000000000001",
  "chainId": "eip155:84532",
  "account": "0x1111111111111111111111111111111111111111",
  "signature": "0x0000000100222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222221b",
  "type": "typed-data"
}

The signature above is illustrative. Keep the actual signature and the exact payload you signed for verification.

Use Integer ValuesCopy Anchor Link

Typed-data messages must be JSON-compatible. For large integer fields such as uint256, use decimal strings rather than JavaScript bigint values or numbers that lose precision. This differs from transaction value, which accepts a bigint.

Match Your Signature PolicyCopy Anchor Link

When your session has typed-data rules, one rule must match the chain, verifying contract, primary type, and any configured domain name and version. Domain names and versions are case-sensitive.

These rules restrict the payload's domain and type, not the amounts inside a permit or other authorization. Review the actual message before signing.

Signing returns a signature; it does not submit the payload to the target contract.