feat: use the pubky.app profile directly

app/src/main/java/to/bitkit/data/PubkyStore.kt

@@ -28,8 +28,14 @@ class PubkyStore @Inject constructor(
         store.updateData(transform)
     }
 
+    /** Clears the session's data but keeps the migration history, so a profile deleted on pubky.app stays deleted. */
     suspend fun reset() {
-        store.updateData { PubkyStoreData() }
+        store.updateData {
+            PubkyStoreData(
+                pubkyAppProfileOwners = it.pubkyAppProfileOwners,
+                pubkyAppAvatarPending = it.pubkyAppAvatarPending,
+            )
+        }
     }
 }
 
@@ -41,6 +47,10 @@ data class PubkyStoreData(
     val cachedName: String? = null,
     val cachedImageUri: String? = null,
     val contactProfileOverrides: Map<String, PubkyProfileData> = emptyMap(),
+    /** Identities Bitkit has seen a pubky.app profile for, so a profile deleted there is not moved back from Bitkit. */
+    val pubkyAppProfileOwners: Set<String> = emptySet(),
+    /** Identities whose Bitkit avatar is still to be moved to pubky.app, retried on each profile load. */
+    val pubkyAppAvatarPending: Set<String> = emptySet(),
 ) {
     fun cachedProfile(): PubkyCachedProfile? = cachedProfileOwner?.let {
         PubkyCachedProfile(publicKey = it, name = cachedName.orEmpty(), imageUri = cachedImageUri)

app/src/main/java/to/bitkit/models/PubkyProfile.kt

@@ -10,6 +10,18 @@ import com.synonym.paykit.PubkyProfile as SdkPubkyProfile
 
 private val pubkyProfileJson = Json { ignoreUnknownKeys = true }
 
+/** pubky.app profile name limits from pubky-app-specs. */
+const val PROFILE_NAME_MIN_LENGTH = 3
+const val PROFILE_NAME_MAX_LENGTH = 50
+const val PROFILE_LINKS_MAX_COUNT = 5
+
+/** pubky.app counts code points, not UTF-16 chars. */
+fun isValidProfileName(name: String) = name.trim().let { it.codePointCount(0, it.length) } in
+    PROFILE_NAME_MIN_LENGTH..PROFILE_NAME_MAX_LENGTH
+
+fun String.takeCodePoints(max: Int) =
+    if (codePointCount(0, length) <= max) this else substring(0, offsetByCodePoints(0, max))
+
 @Immutable
 data class PubkyProfileLink(val label: String, val url: String)
 

app/src/main/java/to/bitkit/services/PaykitSdkService.kt

@@ -70,6 +70,8 @@ import com.synonym.paykit.PubkyClientConfig
 import com.synonym.paykit.PubkyIdentityCapability
 import com.synonym.paykit.PubkyLocalSecretKey
 import com.synonym.paykit.PubkyProfile
+import com.synonym.paykit.PubkyProfileSnapshot
+import com.synonym.paykit.PubkyProfileUpdate
 import com.synonym.paykit.PubkySessionAccess
 import com.synonym.paykit.PubkySessionBootstrap
 import com.synonym.paykit.PubkySessionBootstrapResult
@@ -84,6 +86,7 @@ import com.synonym.paykit.defaultPubkyClientConfig
 import com.synonym.paykit.parsePubkyAuthUrl
 import com.synonym.paykit.paykitAuthorizerSessionCapabilities
 import com.synonym.paykit.paymentProofEventLen
+import com.synonym.paykit.pubkyAppProfileSessionCapabilities
 import com.synonym.paykit.pubkyPublicKeyFromSecret
 import com.synonym.paykit.pubkySecretKeyFromBip39Mnemonic
 import dagger.hilt.android.qualifiers.ApplicationContext
@@ -622,11 +625,12 @@ class PaykitSdkService @Inject constructor(
         publicRead(PaykitReadLane.Bulk, 5.seconds) { it.fetchPubkyFileBounded(uri, maxBytes) }
             ?: throw PubkyFileNotFoundError()
 
-    suspend fun publishPaykitProfile(profile: PaykitProfile): PaykitProfileRecord {
+    suspend fun publishPaykitProfile(profile: PaykitProfile, expectedIdentity: String): PaykitProfileRecord {
         isSetup.await()
         return operationLock.withLock {
             withPaykitKey { handle ->
                 val publicKey = requireNotNull(completeSdkCall { handle.identityStatus() }?.publicKey)
+                requireProfileIdentity(publicKey, expectedIdentity)
                 val current = handle.fetchPaykitProfile(publicKey)
                 completeSdkCall {
                     handle.publishPaykitProfile(profile, current?.revision).also { notifyBackupStateChanged() }
@@ -668,6 +672,46 @@ class PaykitSdkService @Inject constructor(
     suspend fun fetchPubkyProfile(publicKey: String): PubkyProfile? =
         publicRead { it.fetchPubkyProfile(publicKey) }?.profile
 
+    suspend fun fetchPubkyProfileWithRevision(publicKey: String): PubkyProfileSnapshot? =
+        publicRead { it.fetchPubkyProfileWithRevision(publicKey) }
+
+    suspend fun fetchPaykitProfile(publicKey: String): PaykitProfileRecord? =
+        publicRead { it.fetchPaykitProfile(publicKey) }
+
+    suspend fun publishPubkyProfile(
+        update: PubkyProfileUpdate,
+        expectedRevision: String?,
+        expectedIdentity: String,
+    ): PubkyProfileSnapshot {
+        isSetup.await()
+        return operationLock.withLock {
+            requireProfileIdentity(currentIdentity(), expectedIdentity)
+            completeSdkCall { handle().publishPubkyProfile(update, expectedRevision) }
+        }
+    }
+
+    suspend fun deletePubkyProfile(expectedRevision: String, expectedIdentity: String) {
+        isSetup.await()
+        operationLock.withLock {
+            requireProfileIdentity(currentIdentity(), expectedIdentity)
+            completeSdkCall { handle().deletePubkyProfile(expectedRevision) }
+        }
+    }
+
+    suspend fun uploadPubkyAppAvatar(bytes: ByteArray, contentType: String, expectedIdentity: String): String {
+        isSetup.await()
+        return operationLock.withLock {
+            requireProfileIdentity(currentIdentity(), expectedIdentity)
+            completeSdkCall { handle().uploadPubkyAppAvatar(bytes, contentType) }
+        }
+    }
+
+    private suspend fun currentIdentity(): String? = completeSdkCall { handle().identityStatus() }?.publicKey
+
+    private fun requireProfileIdentity(current: String?, expectedIdentity: String) {
+        if (!PubkyPublicKeyFormat.matches(current, expectedIdentity)) throw PubkyProfileIdentityChangedError()
+    }
+
     suspend fun fetchPubkyFollows(publicKey: String): List<String> =
         publicRead { it.fetchPubkyFollows(publicKey, maxEntries = 10_000u) }
 
@@ -885,7 +929,12 @@ class PaykitSdkService @Inject constructor(
         }
     }
 
-    fun requiredCapabilities(): String = paykitAuthorizerSessionCapabilities()
+    /**
+     * Scope for sessions Bitkit creates: Paykit plus the shared pubky.app profile and its avatar.
+     * Restoring a saved session still checks only the Paykit scope, so sessions from older builds keep working.
+     */
+    fun requiredCapabilities(): String =
+        "${paykitAuthorizerSessionCapabilities()},${pubkyAppProfileSessionCapabilities()}"
 
     suspend fun syncPrivatePaymentListsWithReservations(
         updates: List<PrivatePaymentListReservationUpdateInput>,
@@ -2277,3 +2326,6 @@ internal fun <T> paykitStorageCallback(code: String, operation: () -> T): T =
         if (it is PaykitException) throw it
         throw PaykitException.Storage(code = code, context = "Platform Paykit storage operation failed")
     }
+
+/** The signed-in identity changed before a profile write, so it wrote nothing. */
+class PubkyProfileIdentityChangedError : AppError("Pubky identity changed before the profile write")

app/src/main/java/to/bitkit/services/PubkyService.kt

@@ -4,9 +4,12 @@ import com.synonym.bitkitcore.approvePubkyAuth
 import com.synonym.paykit.ContactRecord
 import com.synonym.paykit.ContactUpdate
 import com.synonym.paykit.PaykitProfile
+import com.synonym.paykit.PaykitProfileRecord
 import com.synonym.paykit.PaykitPublicKeys
 import com.synonym.paykit.ProfileResolution
 import com.synonym.paykit.PubkyAuthCompanionClaim
+import com.synonym.paykit.PubkyProfileSnapshot
+import com.synonym.paykit.PubkyProfileUpdate
 import com.synonym.paykit.PubkySessionBootstrapResult
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
@@ -199,8 +202,8 @@ class PubkyService @Inject constructor(
 
     // region Profile & contacts
 
-    suspend fun publishPaykitProfile(profile: PaykitProfile) = ServiceQueue.PUBKY.background {
-        paykitSdkService.publishPaykitProfile(profile)
+    suspend fun publishPaykitProfile(profile: PaykitProfile, expectedIdentity: String) = ServiceQueue.PUBKY.background {
+        paykitSdkService.publishPaykitProfile(profile, expectedIdentity)
     }
 
     suspend fun uploadProfileAvatar(bytes: ByteArray, contentType: String): String = ServiceQueue.PUBKY.background {
@@ -211,6 +214,29 @@ class PubkyService @Inject constructor(
         paykitSdkService.deletePaykitProfile()
     }
 
+    suspend fun fetchPubkyProfileWithRevision(publicKey: String): PubkyProfileSnapshot? = cancellablePublicRead {
+        paykitSdkService.fetchPubkyProfileWithRevision(publicKey)
+    }
+
+    suspend fun fetchPaykitProfile(publicKey: String): PaykitProfileRecord? = cancellablePublicRead {
+        paykitSdkService.fetchPaykitProfile(publicKey)
+    }
+
+    suspend fun publishPubkyProfile(
+        update: PubkyProfileUpdate,
+        expectedRevision: String?,
+        expectedIdentity: String,
+    ): PubkyProfileSnapshot = ServiceQueue.PUBKY.background {
+        paykitSdkService.publishPubkyProfile(update, expectedRevision, expectedIdentity)
+    }
+
+    suspend fun deletePubkyProfile(expectedRevision: String, expectedIdentity: String) = ServiceQueue.PUBKY.background {
+        paykitSdkService.deletePubkyProfile(expectedRevision, expectedIdentity)
+    }
+
+    suspend fun uploadPubkyAppAvatar(bytes: ByteArray, contentType: String, expectedIdentity: String): String =
+        ServiceQueue.PUBKY.background { paykitSdkService.uploadPubkyAppAvatar(bytes, contentType, expectedIdentity) }
+
     suspend fun getContacts(publicKey: String): List<String> = cancellablePublicRead {
         paykitSdkService.fetchPubkyFollows(publicKey)
     }

app/src/main/java/to/bitkit/ui/components/ProfileEditForm.kt

@@ -51,6 +51,7 @@ import dev.chrisbanes.haze.rememberHazeState
 import kotlinx.collections.immutable.ImmutableList
 import kotlinx.collections.immutable.persistentListOf
 import to.bitkit.R
+import to.bitkit.models.takeCodePoints
 import to.bitkit.ui.theme.AppTextFieldDefaults
 import to.bitkit.ui.theme.AppTextStyles
 import to.bitkit.ui.theme.AppThemeSurface
@@ -81,6 +82,7 @@ fun ProfileEditForm(
     modifier: Modifier = Modifier,
     isSaving: Boolean = false,
     isDeleting: Boolean = false,
+    maxLinks: Int? = null,
     avatarContent: @Composable () -> Unit = {},
     publicKeyLabel: String? = null,
     bioPlaceholder: String? = null,
@@ -132,7 +134,7 @@ fun ProfileEditForm(
                     TextInput(
                         enabled = !isBusy,
                         value = bio,
-                        onValueChange = { onBioChange(it.take(BIO_MAX_LENGTH)) },
+                        onValueChange = { onBioChange(it.takeCodePoints(BIO_MAX_LENGTH)) },
                         placeholder = resolvedBioPlaceholder,
                         minLines = 3,
                         maxLines = 4,
@@ -171,25 +173,27 @@ fun ProfileEditForm(
                         )
                     }
                 }
-                PrimaryButton(
-                    text = stringResource(R.string.profile__add_link),
-                    enabled = !isBusy,
-                    onClick = {
-                        focusManager.clearFocus(force = true)
-                        keyboardController?.hide()
-                        onAddLink()
-                    },
-                    size = ButtonSize.Small,
-                    fullWidth = false,
-                    icon = {
-                        Icon(
-                            painter = painterResource(R.drawable.ic_link),
-                            contentDescription = null,
-                            modifier = Modifier.size(16.dp)
-                        )
-                    },
-                    modifier = Modifier.testTag("ProfileEditAddLink")
-                )
+                if (maxLinks == null || links.size < maxLinks) {
+                    PrimaryButton(
+                        text = stringResource(R.string.profile__add_link),
+                        enabled = !isBusy,
+                        onClick = {
+                            focusManager.clearFocus(force = true)
+                            keyboardController?.hide()
+                            onAddLink()
+                        },
+                        size = ButtonSize.Small,
+                        fullWidth = false,
+                        icon = {
+                            Icon(
+                                painter = painterResource(R.drawable.ic_link),
+                                contentDescription = null,
+                                modifier = Modifier.size(16.dp)
+                            )
+                        },
+                        modifier = Modifier.testTag("ProfileEditAddLink")
+                    )
+                }
                 HorizontalDivider()
 
                 FieldLabel(text = stringResource(R.string.profile__edit_tags)) {

app/src/main/java/to/bitkit/ui/screens/profile/CreateProfileScreen.kt

@@ -32,6 +32,7 @@ import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import coil3.compose.AsyncImage
 import to.bitkit.R
+import to.bitkit.models.isValidProfileName
 import to.bitkit.ui.components.BodyM
 import to.bitkit.ui.components.FillHeight
 import to.bitkit.ui.components.GradientCircularProgressIndicator
@@ -137,7 +138,7 @@ private fun Content(
                 PrimaryButton(
                     text = stringResource(R.string.common__continue),
                     onClick = onSave,
-                    enabled = uiState.name.isNotBlank() && !uiState.isSaving,
+                    enabled = isValidProfileName(uiState.name) && !uiState.isSaving,
                     isLoading = uiState.isSaving,
                     modifier = Modifier.testTag("CreateProfileSave")
                 )

app/src/main/java/to/bitkit/ui/screens/profile/CreateProfileViewModel.kt

@@ -17,8 +17,11 @@ import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import to.bitkit.R
+import to.bitkit.models.PROFILE_NAME_MAX_LENGTH
 import to.bitkit.models.PubkyProfileLink
 import to.bitkit.models.Toast
+import to.bitkit.models.takeCodePoints
+import to.bitkit.repositories.PubkyProfileChangedError
 import to.bitkit.repositories.PubkyRepo
 import to.bitkit.ui.components.ProfileEditLink
 import to.bitkit.ui.shared.toast.ToastEventBus
@@ -125,7 +128,7 @@ class CreateProfileViewModel @Inject constructor(
     }
 
     fun onNameChange(name: String) {
-        _uiState.update { it.copy(name = name) }
+        _uiState.update { it.copy(name = name.takeCodePoints(PROFILE_NAME_MAX_LENGTH)) }
     }
 
     fun onBioChange(bio: String) {
@@ -198,11 +201,13 @@ class CreateProfileViewModel @Inject constructor(
             }.onFailure {
                 Logger.error("Failed to create identity", it, context = TAG)
                 _uiState.update { it.copy(isSaving = false) }
+                val changed = it is PubkyProfileChangedError
                 ToastEventBus.send(
                     type = Toast.ToastType.ERROR,
                     title = context.getString(R.string.profile__create_error),
-                    description = it.message,
+                    description = if (changed) context.getString(R.string.profile__edit_changed_error) else it.message,
                 )
+                if (changed) deriveAndCheckRemote()
             }
         }
     }

app/src/main/java/to/bitkit/ui/screens/profile/EditProfileScreen.kt

@@ -30,6 +30,8 @@ import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import coil3.compose.AsyncImage
 import kotlinx.collections.immutable.persistentListOf
 import to.bitkit.R
+import to.bitkit.models.PROFILE_LINKS_MAX_COUNT
+import to.bitkit.models.isValidProfileName
 import to.bitkit.ui.components.AddLinkSheet
 import to.bitkit.ui.components.AddTagSheet
 import to.bitkit.ui.components.GradientCircularProgressIndicator
@@ -166,10 +168,11 @@ private fun Content(
                 onAddTag = onAddTag,
                 onSave = onSave,
                 onCancel = onBackClick,
-                isSaveEnabled = uiState.name.isNotBlank() && !uiState.isBusy,
+                isSaveEnabled = isValidProfileName(uiState.name) && !uiState.isBusy,
                 topBar = topBar,
                 isSaving = uiState.isSaving,
                 isDeleting = uiState.isDeleting,
+                maxLinks = PROFILE_LINKS_MAX_COUNT,
                 avatarContent = {
                     AvatarSection(
                         imageUrl = uiState.imageUrl,