at_client_flutter #

The Flutter layer on top of at_client. Adds pre-built onboarding / authentication dialogs, device-keychain storage for atKeys, and Flutter-specific extensions — so a new Flutter app can go from "user has an atSign" to "authenticated AtClient in hand" with a few widget calls.

Supports mobile, desktop, web, and IoT targets via Flutter.

What's in the box #

Examples #

The authoritative, end-to-end walkthroughs live in this package's example app. Read these rather than copying snippets from here:

• example/lib/walkthrough.dart — all four authentication / onboarding flows (CRAM onboarding, atKeys-file login, keychain login, APKAM enrollment) with the post-auth AtClient initialization. If you only read one file, read this one.
• example/lib/apkam_example.dart — the approve/deny side of APKAM (e.g. a "manager" device approving a new phone's enrollment request).
• example/lib/main.dart — minimal host app wiring the two flows above into navigation.

For a full Flutter app using at_client_flutter in anger, see ../at_client_flutter/examples/todos/ — a shared-todos app that combines onboarding, auth, and the AtCollection<T> API from at_client.

Post-authentication initialization #

Every auth flow ends the same way: create an AtClientPreference, then call AtClientManager.setCurrentAtSign(...) with the atChops and atLookUp from the returned AuthResponse. The details (chosen storage directory, namespace, enrollment id) are all in example/lib/walkthrough.dart in the _setupAtClient(...) function.

Keychain storage #

KeychainStorage wraps the device keychain (iOS / Android / macOS / Windows via biometric_storage) and stores atKeys and enrollment data. The PKAM / APKAM dialogs accept a KeychainAtKeysIo instance as a backup target so successful logins automatically populate the keychain for next time.

Windows apps additionally need:

dependencies:
  biometric_storage: ^4.1.3

Direct usage is rare, but when you need it:

final keychainStorage = KeychainStorage();

AtKeys? alice = await keychainStorage.getAtsign('@alice');
List<String> stored = await keychainStorage.getAllAtsigns();
await keychainStorage.appendAtKeysToKeychain(atKeys);
await keychainStorage.removeAtsignFromKeychain('@alice');

Exporting atKeys #

End users must back up their master atKeys (see at_auth's lifecycle writeup). The keychain → file export:

final atSign = AtClientManager.getInstance().atClient.getCurrentAtSign()!;
final atKeys = await KeychainStorage().getAtsign(atSign);
if (atKeys == null) throw Exception('No keys found for $atSign');

final atKeysIo = FileAtKeysIo(
  filePath: (_) => '/path/to/${atSign}_key.atKeys',
);
atKeysIo.write(atSign, atKeys);

Where to go next #

• at_client — the SDK whose AtClient you end up with after authentication
• at_auth — detailed writeup of the atSign provisioning / onboarding / APKAM lifecycle, platform-neutral
• at_commons — AtKey, Metadata, and friends

Open source usage and contributions #

BSD3-licensed. See CONTRIBUTING.md for guidance on setting up tools, running tests, and raising a PR.