Feature flags

Overview

The PortalFeatureFlags class is used to configure feature flags when initializing the Portal SDK. Each flag corresponds to a specific feature or behavior that can be toggled on or off. All flags are optional and immutable after initialization — they cannot be changed at runtime.

Enabling feature flags

Pass featureFlags when calling portal.initialize():

import 'package:portal_flutter/portal_flutter.dart';

final portal = Portal();

await portal.initialize(
  apiKey: 'CLIENT_API_KEY_OR_CLIENT_SESSION_TOKEN',
  featureFlags: PortalFeatureFlags(
    useEnclaveMpcApi: true,
  ),
);

Available flags

`usePreGeneratedWallet`

Type: bool?
Default: null (disabled)
Description: When enabled, portal.createWallet() attempts to claim a pre-generated wallet share instead of running the standard interactive MPC generation. This can make wallet creation faster. You do not need to change how you call createWallet.

How it works Normally, createWallet runs the interactive MPC key generation protocol in real time. With this flag enabled, the SDK first tries to claim a share from a pre-computed pool. If that fails with an HTTP 5xx response from the enclave, the SDK automatically falls back to the standard generation flow — the fallback is transparent, and createWallet resolves or rejects exactly as it would through the standard flow. Failures that aren’t a 5xx (for example, a malformed request or a network failure) are not retried and propagate as usual. Expected failure cases The most common failure to plan for with this flag enabled is a client that already has a wallet. The enclave rejects the claim with a 400 — Not eligible to claim a pre-generated wallet, or Wallet already exists when it’s caught while finalizing the claim. Because that isn’t a 5xx, the SDK does not fall back to standard generation: createWallet() throws a PortalException carrying the enclave’s message. This applies to any client that already holds a stored signing share — one that created a wallet earlier, recovered a wallet, or had a wallet created on another device — not just a createWallet() call that happens twice in the same session. Only call createWallet() for clients that don’t already have a wallet, and keep a try/catch around it:

try {
  final addresses = await portal.createWallet();
  print('My Portal EVM address: ${addresses.ethereum}');
} on PortalException catch (e) {
  print('Wallet creation failed: ${e.message}');
}

When to enable Enable usePreGeneratedWallet when you want faster wallet creation without changing your integration. The resulting wallet is identical to one created through the standard flow. See Pre-Generated Wallets for a deeper explanation. Limitations

This is a performance optimization only; it doesn’t change the API surface, the resulting wallet, or how backup/recovery works.
Fallback to standard generation happens on an HTTP 5xx response from the enclave only. A 4xx rejection (such as a client that already has a wallet), an unauthorized API key, and network failures propagate normally — so these produce a failed wallet creation rather than a slow one. Keep your existing error handling around createWallet().

Example

import 'package:portal_flutter/portal_flutter.dart';

final portal = Portal();

await portal.initialize(
  apiKey: 'CLIENT_API_KEY_OR_CLIENT_SESSION_TOKEN',
  featureFlags: PortalFeatureFlags(
    usePreGeneratedWallet: true,
  ),
);

`useEnclaveMpcApi`

Type: bool?
Default: null (disabled)
Description: Enables the use of the Enclave MPC API for signing transactions. When enabled, MPC operations are executed server-side in a secure AWS Nitro Enclave, ensuring consistent and faster signing times.

How it works Executing MPC operations on client devices can lead to inconsistent signing times due to variations in device CPU performance. By enabling the useEnclaveMpcApi flag, the client key share is transmitted to a Trusted Execution Environment (TEE) hosted in an AWS Nitro Enclave. This ensures:

Encrypted memory: All data processed in the enclave is encrypted and inaccessible to anyone, including Portal employees.
Verified execution: Users can cryptographically verify that their request was handled in a secure enclave using signed measurements.

Example

import 'package:portal_flutter/portal_flutter.dart';

final portal = Portal();

await portal.initialize(
  apiKey: 'CLIENT_API_KEY_OR_CLIENT_SESSION_TOKEN',
  featureFlags: PortalFeatureFlags(
    useEnclaveMpcApi: true,
  ),
);

`usePresignatures`

Type: bool?
Default: null (disabled)
Description: Enables the automatic use of presignatures to improve signing latency for EVM transactions.

How it works When usePresignatures is enabled, the SDK automatically generates and uses presignatures in the background. This reduces the time required for transactions to be signed, as the SDK pre-computes part of the MPC signing flow. Users do not need to take any additional actions — the SDK handles presignature generation and consumption automatically.

Presignatures currently only support the SECP256K1 curve (EVM, Bitcoin). ED25519 (Solana) signing is unaffected by this flag — support is coming soon.

Example

import 'package:portal_flutter/portal_flutter.dart';

final portal = Portal();

await portal.initialize(
  apiKey: 'CLIENT_API_KEY_OR_CLIENT_SESSION_TOKEN',
  featureFlags: PortalFeatureFlags(
    usePresignatures: true,
  ),
);

Important notes

All feature flags are set at initialization time and cannot be changed at runtime.
Each flag is optional (bool?) — you only need to set the flags you want to enable.
Flags not specified will use their default behavior (disabled).

Getting Started

SDKs

APIs

Integrations

Resources

Overview

Enabling feature flags

Available flags

`usePreGeneratedWallet`

`useEnclaveMpcApi`

`usePresignatures`

Important notes

​Overview

​Enabling feature flags

​Available flags

​usePreGeneratedWallet

​useEnclaveMpcApi

​usePresignatures

​Important notes

Overview

Enabling feature flags

Available flags

`usePreGeneratedWallet`

`useEnclaveMpcApi`

`usePresignatures`

Important notes