# Verify Signatures

> Documentation index: [llms.txt](https://namera.ai/llms.txt).

Source: https://namera.ai/docs/sdk/guides/signing/verify-signatures

Check a smart-account signature against its original message or typed data.

Use `verifySignature()` with the original payload, account ID, network, and
signature. Verification is read-only and does not need a `sessionKeyId`.
Your credential must still have access to the account.

## Verify a Message [#verify-a-message]

This runnable example signs a message, then verifies the returned signature.
Use [authentication](https://namera.ai/docs/sdk/authentication) and replace the IDs with an
account and session key configured for [message signing](https://namera.ai/docs/sdk/guides/signing/sign-messages).

```sh
npm install @namera-ai/sdk
```

```ts title="index.ts"
import { NameraClient } from "@namera-ai/sdk";

const namera = new NameraClient({ apiKey: process.env.NAMERA_API_KEY! });
const walletId = "0199dfe1-0000-7000-8000-000000000001";
const sessionKeyId = "0199dfe1-0000-7000-8000-000000000002";
const message = "Hello from Namera";

const signed = await namera.sign({
  namespace: "eip155",
  walletId,
  sessionKeyId,
  chainId: "eip155:84532",
  type: "message",
  message,
});

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

const verification = await namera.verifySignature({
  namespace: "eip155",
  walletId,
  chainId: "eip155:84532",
  type: "message",
  message,
  signature: signed.data.signature,
});

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

console.log(verification.data);
```

<div className="docs-response">

```json
{
  "namespace": "eip155",
  "walletId": "0199dfe1-0000-7000-8000-000000000001",
  "chainId": "eip155:84532",
  "account": "0x1111111111111111111111111111111111111111",
  "valid": true,
  "type": "message"
}
```

</div>

If you already have a signature, skip `sign()` and pass that signature to
`verifySignature()`. Preserve the original message exactly, including whitespace.

## Verify Typed Data [#verify-typed-data]

After [signing typed data](https://namera.ai/docs/sdk/guides/signing/sign-typed-data), add this
snippet to that example. It uses the existing `namera`, `typedData`, and successful
`signed` result from that page:

```ts title="index.ts"
const verification = await namera.verifySignature({
  namespace: "eip155",
  walletId: signed.data.walletId,
  chainId: signed.data.chainId,
  type: "typed-data",
  typedData,
  signature: signed.data.signature,
});

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

console.log(verification.data);
```

<div className="docs-response">

```json
{
  "namespace": "eip155",
  "walletId": "0199dfe1-0000-7000-8000-000000000001",
  "chainId": "eip155:84532",
  "account": "0x1111111111111111111111111111111111111111",
  "valid": true,
  "type": "typed-data"
}
```

</div>

Supply the same domain, types, primary type, and message that were signed.
Changing a field changes the payload being verified.

## Read the Outcome [#read-the-outcome]

`success: true` means the verification request completed. Only `data.valid: true`
means the signature was accepted for that account and payload. Treat
`valid: false` as an invalid signature; handle `success: false` as a request error.

<Callout title="Verify the smart account, not an EOA">
  Namera returns smart-account signatures. Recovering an EOA address from the signature is not a
  substitute for checking the account's signature validation.
</Callout>