Domain and transaction warnings

Phantom may display different warnings when users connect to your app or sign transactions. These warnings are designed to help protect users from unexpected or unsafe activity.

New domain warning

If your app or website has been newly launched, Phantom may show users the following message:

“This domain is new or has not been reviewed yet. Proceed with caution.”

Warning message shown when connecting to a new or unverified domain

This warning appears automatically for newly detected domains and typically disappears after a few days once the domain has been reviewed. There’s usually no action required on your part. If the warning remains visible for more than a week, contact our domain review team using this form.

App identity verification warning

When users connect to a native Android app through Mobile Wallet Adapter (MWA), Phantom verifies that the app is genuinely associated with the web domain it claims as its identity. If Phantom can’t complete this verification, users see the following message:

“This app’s identity could not be verified. It may be impersonating another app.”

This verification is domain-based, as defined in the MWA dapp identity verification spec. Phantom checks the Digital Asset Links file hosted on your domain and confirms that your app’s package name and signing certificate match an android_app statement in that file. The warning appears when any of the following verification requirements are missing:

Your authorize request doesn’t include a uri in its identity.
Your domain doesn’t host a Digital Asset Links file at /.well-known/assetlinks.json.
Your app’s package name or signing certificate fingerprint doesn’t match the statements in the file.

Resolve the warning

1. Host a Digital Asset Links file Publish https://yourapp.com/.well-known/assetlinks.json declaring your app’s package name and the SHA-256 fingerprint of its signing certificate:

[
  {
    "relation": ["delegate_permission/common.handle_all_urls"],
    "target": {
      "namespace": "android_app",
      "package_name": "com.yourapp.android",
      "sha256_cert_fingerprints": [
        "AA:BB:CC:DD:EE:FF:00:11:22:33:44:55:66:77:88:99:AA:BB:CC:DD:EE:FF:00:11:22:33:44:55:66:77:88:99"
      ]
    }
  }
]

If you distribute through Google Play with Play App Signing, use the app signing key certificate fingerprint from the Play Console (Protected with Play → Play Store protection → Manage Play app signing), not your upload key. A mismatched fingerprint is the most common cause of failed verification.

2. Include your domain in the identity of your authorization request The uri must point to the domain that hosts your assetlinks.json file:

import { transact } from "@solana-mobile/mobile-wallet-adapter-protocol-web3js";

try {
  const authorization = await transact(async (wallet) => {
    return await wallet.authorize({
      chain: "solana:mainnet",
      identity: {
        name: "Your App",
        uri: "https://yourapp.com", // Domain hosting /.well-known/assetlinks.json
        icon: "favicon.ico",
      },
    });
  });
  console.log("Authorized:", authorization.accounts[0]?.address);
} catch (err) {
  // Thrown if the user declines, or if the wallet rejects the request
  console.error("Authorization failed:", err.message);
}

You can confirm your Digital Asset Links file is live and valid with the following command, which fails if the file is missing or isn’t a JSON array:

curl --fail https://yourapp.com/.well-known/assetlinks.json | jq -e 'type == "array"'

Once the file is correctly hosted and your signing certificate matches, verification completes automatically on the next connection. No submission to Phantom is required.

Transaction simulation warning

If Phantom can’t accurately simulate a transaction before it’s sent, users may see the following message:

“This dApp could be malicious. Do not proceed unless you are certain it is safe.”

Warning displayed when Phantom can’t confirm the safety of a transaction

This message appears when Phantom is unable to safely predict a transaction’s outcome before execution. If Phantom displays this warning when you sign a transaction on your domain, follow these steps:

Use Solana v1 transactions when supported by the connected signer. Set compute unit and loaded account data limits explicitly in the message configuration. Ledger does not currently support signing v1 transactions; offer a v0 option when the operation can be built as v0. See Ledger’s support issue for updates.
Sign with Phantom using signTransaction, then submit the transaction Phantom returns through your RPC node with preflight enabled.
Limit the transaction to one signer. If you need multiple signers, have Phantom sign first, then collect the other signatures on the transaction Phantom returns.
If your transaction approaches its size limit, split it into multiple signing requests. For v0 transactions, you can also use Address Lookup Tables.
Before submitting the transaction for signing, simulate the transaction with sigVerify: false using your RPC node to ensure it will not fail onchain. Failed transactions could trigger simulation warnings.

For copyable examples, see Send a Solana v1 transaction and Resolve transaction simulation warnings. If you’ve made these changes and the warning persists, or if you can’t apply these changes, contact our domain review team using this form.

Prediction market token burn warning

If a transaction attempts to burn a prediction market token, Phantom may show users the following message:

“This transaction will burn a valuable prediction market token. Please use the Phantom app to close the position first.”

This warning appears when Phantom detects a transaction that would permanently burn a prediction market token. To resolve this warning, contact our Trust and Safety team using this form.

Overview

Developer tools

Security and validation

Solana features

Testing and debugging

Best practices

Resources

Traditional Provider

Mobile Deep Links

New domain warning

App identity verification warning

Resolve the warning

Transaction simulation warning

Prediction market token burn warning

​New domain warning

​App identity verification warning

​Resolve the warning

​Transaction simulation warning

​Prediction market token burn warning

New domain warning

App identity verification warning

Resolve the warning

Transaction simulation warning

Prediction market token burn warning