diff --git a/crud.py b/crud.py
index cd610b1..0976e72 100644
--- a/crud.py
+++ b/crud.py
@@ -424,26 +424,6 @@ async def get_user_wallet_settings(user_id: str) -> Optional[UserWalletSettings]
     )
 
 
-async def get_user_wallet_settings_by_prefix(
-    user_id_prefix: str,
-) -> Optional[StoredUserWalletSettings]:
-    """
-    Get user wallet settings by user ID prefix (for truncated 8-char IDs from Beancount).
-
-    Beancount accounts use truncated user IDs (first 8 chars), but the database
-    stores full UUIDs. This function looks up by prefix to bridge the gap.
-    """
-    return await db.fetchone(
-        """
-        SELECT * FROM user_wallet_settings
-        WHERE id LIKE :prefix || '%'
-        LIMIT 1
-        """,
-        {"prefix": user_id_prefix},
-        StoredUserWalletSettings,
-    )
-
-
 async def update_user_wallet_settings(
     user_id: str, data: UserWalletSettings
 ) -> UserWalletSettings:
diff --git a/fava_client.py b/fava_client.py
index 6880d11..38e932a 100644
--- a/fava_client.py
+++ b/fava_client.py
@@ -17,7 +17,6 @@ Fava provides a REST API for:
 See: https://github.com/beancount/fava/blob/main/src/fava/json_api.py
 """
 
-import asyncio
 import httpx
 from typing import Any, Dict, List, Optional
 from decimal import Decimal
@@ -25,11 +24,6 @@ from datetime import date, datetime
 from loguru import logger
 
 
-class ChecksumConflictError(Exception):
-    """Raised when a Fava write operation fails due to stale checksum (concurrent modification)."""
-    pass
-
-
 class FavaClient:
     """
     Async client for Fava REST API.
@@ -54,37 +48,6 @@ class FavaClient:
         self.base_url = f"{self.fava_url}/{self.ledger_slug}/api"
         self.timeout = timeout
 
-        # Concurrency control: Global write lock to serialize all ledger modifications.
-        # This prevents race conditions when multiple requests try to write to the
-        # Beancount ledger file simultaneously. Without this lock, concurrent writes
-        # can cause data loss, duplicate entries, or file corruption.
-        #
-        # Note: This serializes ALL writes which may become a bottleneck at scale.
-        # For higher throughput, consider per-user locking or distributed locking.
-        self._write_lock = asyncio.Lock()
-
-        # Per-user locks for user-specific operations (reduces contention)
-        self._user_locks: Dict[str, asyncio.Lock] = {}
-
-    def get_user_lock(self, user_id: str) -> asyncio.Lock:
-        """
-        Get or create a lock for a specific user.
-
-        This enables per-user locking to reduce contention when multiple users
-        are making concurrent requests. User-specific operations should acquire
-        this lock in addition to (or instead of) the global write lock.
-
-        Args:
-            user_id: User ID (uses first 8 characters for consistency)
-
-        Returns:
-            asyncio.Lock for this user
-        """
-        user_key = user_id[:8]
-        if user_key not in self._user_locks:
-            self._user_locks[user_key] = asyncio.Lock()
-        return self._user_locks[user_key]
-
     async def add_entry(self, entry: Dict[str, Any]) -> Dict[str, Any]:
         """
         Submit a new journal entry to Fava.
@@ -125,100 +88,26 @@ class FavaClient:
                 "meta": {"user_id": "abc123"}
             }
             result = await fava_client.add_entry(entry)
-
-        Note:
-            This method acquires a global write lock to prevent concurrent
-            modifications to the ledger file. All writes are serialized.
         """
-        # Acquire global write lock to serialize ledger modifications
-        async with self._write_lock:
-            try:
-                async with httpx.AsyncClient(timeout=self.timeout) as client:
-                    response = await client.put(
-                        f"{self.base_url}/add_entries",
-                        json={"entries": [entry]},
-                        headers={"Content-Type": "application/json"}
-                    )
-                    response.raise_for_status()
-                    result = response.json()
-
-                    logger.info(f"Added entry to Fava: {result.get('data', 'Unknown')}")
-                    return result
-
-            except httpx.HTTPStatusError as e:
-                logger.error(f"Fava HTTP error: {e.response.status_code} - {e.response.text}")
-                raise
-            except httpx.RequestError as e:
-                logger.error(f"Fava connection error: {e}")
-                raise
-
-    async def add_entry_idempotent(
-        self,
-        entry: Dict[str, Any],
-        idempotency_key: str
-    ) -> Dict[str, Any]:
-        """
-        Submit a journal entry with idempotency protection.
-
-        This method checks if an entry with the given idempotency key (as a Beancount link)
-        already exists before inserting. This prevents duplicate entries when the same
-        operation is retried (e.g., due to network issues or concurrent requests).
-
-        The idempotency key is stored as a Beancount link on the entry. Links are part
-        of the entry's identity and are indexed by Beancount, making lookup efficient.
-
-        Args:
-            entry: Beancount entry dict (same format as add_entry)
-            idempotency_key: Unique key for this operation (e.g., "castle-{uuid}" or "ln-{payment_hash}")
-
-        Returns:
-            Response from Fava if entry was created, or existing entry data if already exists
-
-        Example:
-            # Use payment hash as idempotency key for Lightning payments
-            result = await fava.add_entry_idempotent(
-                entry=settlement_entry,
-                idempotency_key=f"ln-{payment_hash[:16]}"
-            )
-
-            # Use expense ID for expense entries
-            result = await fava.add_entry_idempotent(
-                entry=expense_entry,
-                idempotency_key=f"exp-{expense_id}"
-            )
-        """
-        from .beancount_format import sanitize_link
-
-        # Sanitize the idempotency key to ensure it's a valid Beancount link
-        safe_key = sanitize_link(idempotency_key)
-
-        # Check if entry with this link already exists
         try:
-            entries = await self.get_journal_entries(days=30)  # Check recent entries
+            async with httpx.AsyncClient(timeout=self.timeout) as client:
+                response = await client.put(
+                    f"{self.base_url}/add_entries",
+                    json={"entries": [entry]},
+                    headers={"Content-Type": "application/json"}
+                )
+                response.raise_for_status()
+                result = response.json()
 
-            for existing_entry in entries:
-                existing_links = existing_entry.get("links", [])
-                if safe_key in existing_links:
-                    logger.info(f"Entry with idempotency key '{safe_key}' already exists, skipping insert")
-                    return {
-                        "data": "Entry already exists (idempotent)",
-                        "existing": True,
-                        "entry": existing_entry
-                    }
-        except Exception as e:
-            logger.warning(f"Could not check for existing entry with key '{safe_key}': {e}")
-            # Continue anyway - Beancount will error if there's a true duplicate
+                logger.info(f"Added entry to Fava: {result.get('data', 'Unknown')}")
+                return result
 
-        # Add the idempotency key as a link if not already present
-        if "links" not in entry:
-            entry["links"] = []
-        if safe_key not in entry["links"]:
-            entry["links"].append(safe_key)
-
-        # Now add the entry (this will acquire the write lock)
-        result = await self.add_entry(entry)
-        result["existing"] = False
-        return result
+        except httpx.HTTPStatusError as e:
+            logger.error(f"Fava HTTP error: {e.response.status_code} - {e.response.text}")
+            raise
+        except httpx.RequestError as e:
+            logger.error(f"Fava connection error: {e}")
+            raise
 
     async def get_account_balance(self, account_name: str) -> Dict[str, Any]:
         """
@@ -1257,10 +1146,6 @@ class FavaClient:
         Returns:
             New sha256sum after update
 
-        Note:
-            This method acquires a global write lock to prevent concurrent
-            modifications to the ledger file. All writes are serialized.
-
         Example:
             # Get context
             context = await fava.get_entry_context("abc123")
@@ -1273,28 +1158,26 @@ class FavaClient:
             # Update
             new_sha256 = await fava.update_entry_source("abc123", new_source, sha256)
         """
-        # Acquire global write lock to serialize ledger modifications
-        async with self._write_lock:
-            try:
-                async with httpx.AsyncClient(timeout=self.timeout) as client:
-                    response = await client.put(
-                        f"{self.base_url}/source_slice",
-                        json={
-                            "entry_hash": entry_hash,
-                            "source": new_source,
-                            "sha256sum": sha256sum
-                        }
-                    )
-                    response.raise_for_status()
-                    result = response.json()
-                    return result.get("data", "")
+        try:
+            async with httpx.AsyncClient(timeout=self.timeout) as client:
+                response = await client.put(
+                    f"{self.base_url}/source_slice",
+                    json={
+                        "entry_hash": entry_hash,
+                        "source": new_source,
+                        "sha256sum": sha256sum
+                    }
+                )
+                response.raise_for_status()
+                result = response.json()
+                return result.get("data", "")
 
-            except httpx.HTTPStatusError as e:
-                logger.error(f"Fava update error: {e.response.status_code} - {e.response.text}")
-                raise
-            except httpx.RequestError as e:
-                logger.error(f"Fava connection error: {e}")
-                raise
+        except httpx.HTTPStatusError as e:
+            logger.error(f"Fava update error: {e.response.status_code} - {e.response.text}")
+            raise
+        except httpx.RequestError as e:
+            logger.error(f"Fava connection error: {e}")
+            raise
 
     async def delete_entry(self, entry_hash: str, sha256sum: str) -> str:
         """
@@ -1307,43 +1190,36 @@ class FavaClient:
         Returns:
             Success message
 
-        Note:
-            This method acquires a global write lock to prevent concurrent
-            modifications to the ledger file. All writes are serialized.
-
         Example:
             context = await fava.get_entry_context("abc123")
             await fava.delete_entry("abc123", context["sha256sum"])
         """
-        # Acquire global write lock to serialize ledger modifications
-        async with self._write_lock:
-            try:
-                async with httpx.AsyncClient(timeout=self.timeout) as client:
-                    response = await client.delete(
-                        f"{self.base_url}/source_slice",
-                        params={
-                            "entry_hash": entry_hash,
-                            "sha256sum": sha256sum
-                        }
-                    )
-                    response.raise_for_status()
-                    result = response.json()
-                    return result.get("data", "")
+        try:
+            async with httpx.AsyncClient(timeout=self.timeout) as client:
+                response = await client.delete(
+                    f"{self.base_url}/source_slice",
+                    params={
+                        "entry_hash": entry_hash,
+                        "sha256sum": sha256sum
+                    }
+                )
+                response.raise_for_status()
+                result = response.json()
+                return result.get("data", "")
 
-            except httpx.HTTPStatusError as e:
-                logger.error(f"Fava delete error: {e.response.status_code} - {e.response.text}")
-                raise
-            except httpx.RequestError as e:
-                logger.error(f"Fava connection error: {e}")
-                raise
+        except httpx.HTTPStatusError as e:
+            logger.error(f"Fava delete error: {e.response.status_code} - {e.response.text}")
+            raise
+        except httpx.RequestError as e:
+            logger.error(f"Fava connection error: {e}")
+            raise
 
     async def add_account(
         self,
         account_name: str,
         currencies: list[str],
         opening_date: Optional[date] = None,
-        metadata: Optional[Dict[str, Any]] = None,
-        max_retries: int = 3
+        metadata: Optional[Dict[str, Any]] = None
     ) -> Dict[str, Any]:
         """
         Add an account to the Beancount ledger via an Open directive.
@@ -1351,25 +1227,15 @@ class FavaClient:
         NOTE: Fava's /api/add_entries endpoint does NOT support Open directives.
         This method uses /api/source to directly edit the Beancount file.
 
-        This method implements optimistic concurrency control with retry logic:
-        - Acquires a global write lock before modifying the ledger
-        - Uses SHA256 checksum to detect concurrent modifications
-        - Retries with exponential backoff on checksum conflicts
-        - Re-checks if account was created by concurrent request before retrying
-
         Args:
             account_name: Full account name (e.g., "Assets:Receivable:User-abc123")
             currencies: List of currencies for this account (e.g., ["EUR", "SATS"])
             opening_date: Date to open the account (defaults to today)
             metadata: Optional metadata for the account
-            max_retries: Maximum number of retry attempts on checksum conflict (default: 3)
 
         Returns:
             Response from Fava ({"data": "new_sha256sum", "mtime": "..."})
 
-        Raises:
-            ChecksumConflictError: If all retry attempts fail due to concurrent modifications
-
         Example:
             # Add a user's receivable account
             result = await fava.add_account(
@@ -1389,115 +1255,89 @@ class FavaClient:
         if opening_date is None:
             opening_date = date_type.today()
 
-        last_error = None
+        try:
+            async with httpx.AsyncClient(timeout=self.timeout) as client:
+                # Step 1: Get the main Beancount file path from Fava
+                options_response = await client.get(f"{self.base_url}/options")
+                options_response.raise_for_status()
+                options_data = options_response.json()["data"]
+                file_path = options_data["beancount_options"]["filename"]
 
-        for attempt in range(max_retries):
-            # Acquire global write lock to serialize ledger modifications
-            async with self._write_lock:
-                try:
-                    async with httpx.AsyncClient(timeout=self.timeout) as client:
-                        # Step 1: Get the main Beancount file path from Fava
-                        options_response = await client.get(f"{self.base_url}/options")
-                        options_response.raise_for_status()
-                        options_data = options_response.json()["data"]
-                        file_path = options_data["beancount_options"]["filename"]
+                logger.debug(f"Fava main file: {file_path}")
 
-                        logger.debug(f"Fava main file: {file_path}")
+                # Step 2: Get current source file
+                response = await client.get(
+                    f"{self.base_url}/source",
+                    params={"filename": file_path}
+                )
+                response.raise_for_status()
+                source_data = response.json()["data"]
 
-                        # Step 2: Get current source file (fresh read on each attempt)
-                        response = await client.get(
-                            f"{self.base_url}/source",
-                            params={"filename": file_path}
-                        )
-                        response.raise_for_status()
-                        source_data = response.json()["data"]
+                sha256sum = source_data["sha256sum"]
+                source = source_data["source"]
 
-                        sha256sum = source_data["sha256sum"]
-                        source = source_data["source"]
+                # Step 2: Check if account already exists
+                if f"open {account_name}" in source:
+                    logger.info(f"Account {account_name} already exists in Beancount file")
+                    return {"data": sha256sum, "mtime": source_data.get("mtime", "")}
 
-                        # Step 3: Check if account already exists (may have been created by concurrent request)
-                        if f"open {account_name}" in source:
-                            logger.info(f"Account {account_name} already exists in Beancount file")
-                            return {"data": sha256sum, "mtime": source_data.get("mtime", "")}
+                # Step 3: Find insertion point (after last Open directive AND its metadata)
+                lines = source.split('\n')
+                insert_index = 0
+                for i, line in enumerate(lines):
+                    if line.strip().startswith(('open ', f'{opening_date.year}-')) and 'open' in line:
+                        # Found an Open directive, now skip over any metadata lines
+                        insert_index = i + 1
+                        # Skip metadata lines (lines starting with whitespace)
+                        while insert_index < len(lines) and lines[insert_index].startswith((' ', '\t')) and lines[insert_index].strip():
+                            insert_index += 1
 
-                        # Step 4: Find insertion point (after last Open directive AND its metadata)
-                        lines = source.split('\n')
-                        insert_index = 0
-                        for i, line in enumerate(lines):
-                            if line.strip().startswith(('open ', f'{opening_date.year}-')) and 'open' in line:
-                                # Found an Open directive, now skip over any metadata lines
-                                insert_index = i + 1
-                                # Skip metadata lines (lines starting with whitespace)
-                                while insert_index < len(lines) and lines[insert_index].startswith((' ', '\t')) and lines[insert_index].strip():
-                                    insert_index += 1
+                # Step 4: Format Open directive as Beancount text
+                currencies_str = ", ".join(currencies)
+                open_lines = [
+                    "",
+                    f"{opening_date.isoformat()} open {account_name} {currencies_str}"
+                ]
 
-                        # Step 5: Format Open directive as Beancount text
-                        currencies_str = ", ".join(currencies)
-                        open_lines = [
-                            "",
-                            f"{opening_date.isoformat()} open {account_name} {currencies_str}"
-                        ]
+                # Add metadata if provided
+                if metadata:
+                    for key, value in metadata.items():
+                        # Format metadata with proper indentation
+                        if isinstance(value, str):
+                            open_lines.append(f'  {key}: "{value}"')
+                        else:
+                            open_lines.append(f'  {key}: {value}')
 
-                        # Add metadata if provided
-                        if metadata:
-                            for key, value in metadata.items():
-                                # Format metadata with proper indentation
-                                if isinstance(value, str):
-                                    open_lines.append(f'  {key}: "{value}"')
-                                else:
-                                    open_lines.append(f'  {key}: {value}')
+                # Step 5: Insert into source
+                for i, line in enumerate(open_lines):
+                    lines.insert(insert_index + i, line)
 
-                        # Step 6: Insert into source
-                        for i, line in enumerate(open_lines):
-                            lines.insert(insert_index + i, line)
+                new_source = '\n'.join(lines)
 
-                        new_source = '\n'.join(lines)
+                # Step 6: Update source file via PUT /api/source
+                update_payload = {
+                    "file_path": file_path,
+                    "source": new_source,
+                    "sha256sum": sha256sum
+                }
 
-                        # Step 7: Update source file via PUT /api/source
-                        update_payload = {
-                            "file_path": file_path,
-                            "source": new_source,
-                            "sha256sum": sha256sum
-                        }
+                response = await client.put(
+                    f"{self.base_url}/source",
+                    json=update_payload,
+                    headers={"Content-Type": "application/json"}
+                )
+                response.raise_for_status()
+                result = response.json()
 
-                        response = await client.put(
-                            f"{self.base_url}/source",
-                            json=update_payload,
-                            headers={"Content-Type": "application/json"}
-                        )
-                        response.raise_for_status()
-                        result = response.json()
+                logger.info(f"Added account {account_name} to Beancount file with currencies {currencies}")
+                return result
 
-                        logger.info(f"Added account {account_name} to Beancount file with currencies {currencies}")
-                        return result
-
-                except httpx.HTTPStatusError as e:
-                    # Check for checksum conflict (HTTP 412 Precondition Failed or similar)
-                    if e.response.status_code in (409, 412):
-                        last_error = ChecksumConflictError(
-                            f"Checksum conflict on attempt {attempt + 1}/{max_retries}: {e.response.text}"
-                        )
-                        logger.warning(
-                            f"Checksum conflict adding account {account_name} "
-                            f"(attempt {attempt + 1}/{max_retries}), retrying..."
-                        )
-                        # Continue to retry logic below
-                    else:
-                        logger.error(f"Fava HTTP error adding account: {e.response.status_code} - {e.response.text}")
-                        raise
-                except httpx.RequestError as e:
-                    logger.error(f"Fava connection error: {e}")
-                    raise
-
-            # If we get here due to checksum conflict, wait with exponential backoff before retry
-            if attempt < max_retries - 1:
-                backoff_time = 0.1 * (2 ** attempt)  # 0.1s, 0.2s, 0.4s
-                logger.info(f"Waiting {backoff_time}s before retry...")
-                await asyncio.sleep(backoff_time)
-
-        # All retries exhausted
-        logger.error(f"Failed to add account {account_name} after {max_retries} attempts due to concurrent modifications")
-        raise last_error or ChecksumConflictError(f"Failed to add account after {max_retries} attempts")
+        except httpx.HTTPStatusError as e:
+            logger.error(f"Fava HTTP error adding account: {e.response.status_code} - {e.response.text}")
+            raise
+        except httpx.RequestError as e:
+            logger.error(f"Fava connection error: {e}")
+            raise
 
     async def get_unsettled_entries_bql(
         self,
diff --git a/services.py b/services.py
index 51c4bd8..1f9d826 100644
--- a/services.py
+++ b/services.py
@@ -18,29 +18,12 @@ async def get_settings(user_id: str) -> CastleSettings:
 
 
 async def update_settings(user_id: str, data: CastleSettings) -> CastleSettings:
-    from loguru import logger
-
-    from .fava_client import init_fava_client
-
     settings = await get_castle_settings(user_id)
     if not settings:
         settings = await create_castle_settings(user_id, data)
     else:
         settings = await update_castle_settings(user_id, data)
 
-    # Reinitialize Fava client with new settings
-    try:
-        init_fava_client(
-            fava_url=settings.fava_url,
-            ledger_slug=settings.fava_ledger_slug,
-            timeout=settings.fava_timeout,
-        )
-        logger.info(
-            f"Fava client reinitialized: {settings.fava_url}/{settings.fava_ledger_slug}"
-        )
-    except Exception as e:
-        logger.error(f"Failed to reinitialize Fava client: {e}")
-
     return settings
 
 
diff --git a/static/js/index.js b/static/js/index.js
index bd52e39..3fc736e 100644
--- a/static/js/index.js
+++ b/static/js/index.js
@@ -31,7 +31,6 @@ window.app = Vue.createApp({
       userInfo: null, // User information including equity eligibility
       isAdmin: false,
       isSuperUser: false,
-      settingsLoaded: false, // Flag to prevent race conditions on toolbar buttons
       castleWalletConfigured: false,
       userWalletConfigured: false,
       currentExchangeRate: null, // BTC/EUR rate (sats per EUR)
@@ -58,9 +57,6 @@ window.app = Vue.createApp({
       settingsDialog: {
         show: false,
         castleWalletId: '',
-        favaUrl: 'http://localhost:3333',
-        favaLedgerSlug: 'castle-ledger',
-        favaTimeout: 10.0,
         loading: false
       },
       userWalletDialog: {
@@ -521,9 +517,6 @@ window.app = Vue.createApp({
       } catch (error) {
         // Settings not available
         this.castleWalletConfigured = false
-      } finally {
-        // Mark settings as loaded to enable toolbar buttons
-        this.settingsLoaded = true
       }
     },
     async loadUserWallet() {
@@ -541,9 +534,6 @@ window.app = Vue.createApp({
     },
     showSettingsDialog() {
       this.settingsDialog.castleWalletId = this.settings?.castle_wallet_id || ''
-      this.settingsDialog.favaUrl = this.settings?.fava_url || 'http://localhost:3333'
-      this.settingsDialog.favaLedgerSlug = this.settings?.fava_ledger_slug || 'castle-ledger'
-      this.settingsDialog.favaTimeout = this.settings?.fava_timeout || 10.0
       this.settingsDialog.show = true
     },
     showUserWalletDialog() {
@@ -559,14 +549,6 @@ window.app = Vue.createApp({
         return
       }
 
-      if (!this.settingsDialog.favaUrl) {
-        this.$q.notify({
-          type: 'warning',
-          message: 'Fava URL is required'
-        })
-        return
-      }
-
       this.settingsDialog.loading = true
       try {
         await LNbits.api.request(
@@ -574,10 +556,7 @@ window.app = Vue.createApp({
           '/castle/api/v1/settings',
           this.g.user.wallets[0].adminkey,
           {
-            castle_wallet_id: this.settingsDialog.castleWalletId,
-            fava_url: this.settingsDialog.favaUrl,
-            fava_ledger_slug: this.settingsDialog.favaLedgerSlug || 'castle-ledger',
-            fava_timeout: parseFloat(this.settingsDialog.favaTimeout) || 10.0
+            castle_wallet_id: this.settingsDialog.castleWalletId
           }
         )
         this.$q.notify({
@@ -1424,7 +1403,7 @@ window.app = Vue.createApp({
         maxAmount: maxAmountSats, // Positive sats amount castle owes
         maxAmountFiat: maxAmountFiat, // EUR or other fiat amount (positive)
         fiatCurrency: fiatCurrency,
-        amount: maxAmountSats, // Default to sats since lightning is the default payment method
+        amount: fiatCurrency ? maxAmountFiat : maxAmountSats, // Default to fiat if available
         payment_method: 'lightning', // Default to lightning for paying
         description: '',
         reference: '',
@@ -1456,9 +1435,8 @@ window.app = Vue.createApp({
             memo: `Payment from Castle to ${this.payUserDialog.username}`
           }
         )
-        console.log(invoiceResponse)
 
-        const paymentRequest = invoiceResponse.data.bolt11
+        const paymentRequest = invoiceResponse.data.payment_request
 
         // Pay the invoice from Castle's wallet
         const paymentResponse = await LNbits.api.request(
diff --git a/static/js/permissions.js b/static/js/permissions.js
index 4cc54f0..0de3569 100644
--- a/static/js/permissions.js
+++ b/static/js/permissions.js
@@ -1118,3 +1118,5 @@ window.app = Vue.createApp({
     }
   }
 })
+
+window.app.mount('#vue')
diff --git a/tasks.py b/tasks.py
index 8ec83b9..b44c883 100644
--- a/tasks.py
+++ b/tasks.py
@@ -187,12 +187,6 @@ async def on_invoice_paid(payment: Payment) -> None:
     This function is called automatically when any invoice on the Castle wallet
     is paid. It checks if the invoice is a Castle payment and records it in
     Beancount via Fava.
-
-    Concurrency Protection:
-    - Uses per-user locking to prevent race conditions when multiple payments
-      for the same user are processed simultaneously
-    - Uses idempotent entry creation to prevent duplicate entries even if
-      the same payment is processed multiple times
     """
     # Only process Castle-specific payments
     if not payment.extra or payment.extra.get("tag") != "castle":
@@ -203,120 +197,134 @@ async def on_invoice_paid(payment: Payment) -> None:
         logger.warning(f"Castle invoice {payment.payment_hash} missing user_id in metadata")
         return
 
+    # Check if payment already recorded (idempotency)
+    # Query Fava for existing entry with this payment hash link
     from .fava_client import get_fava_client
+    import httpx
 
     fava = get_fava_client()
 
-    # Use idempotency key based on payment hash - this ensures duplicate
-    # processing of the same payment won't create duplicate entries
-    idempotency_key = f"ln-{payment.payment_hash[:16]}"
+    try:
+        # Check if payment already recorded by fetching recent entries
+        # Note: We can't use BQL query with `links ~ 'pattern'` because links is a set type
+        # and BQL doesn't support regex matching on sets. Instead, fetch entries and filter in Python.
+        link_to_find = f"ln-{payment.payment_hash[:16]}"
 
-    # Acquire per-user lock to serialize processing for this user
-    # This prevents race conditions when a user has multiple payments being processed
-    user_lock = fava.get_user_lock(user_id)
+        async with httpx.AsyncClient(timeout=5.0) as client:
+            # Get recent entries from Fava's journal endpoint
+            response = await client.get(
+                f"{fava.base_url}/api/journal",
+                params={"time": ""}  # Get all entries
+            )
 
-    async with user_lock:
-        logger.info(f"Recording Castle payment {payment.payment_hash} for user {user_id[:8]} to Fava")
+            if response.status_code == 200:
+                data = response.json()
+                entries = data.get('entries', [])
 
+                # Check if any entry has our payment link
+                for entry in entries:
+                    entry_links = entry.get('links', [])
+                    if link_to_find in entry_links:
+                        logger.info(f"Payment {payment.payment_hash} already recorded in Fava, skipping")
+                        return
+
+    except Exception as e:
+        logger.warning(f"Could not check Fava for duplicate payment: {e}")
+        # Continue anyway - Fava/Beancount will catch duplicate if it exists
+
+    logger.info(f"Recording Castle payment {payment.payment_hash} for user {user_id[:8]} to Fava")
+
+    try:
+        from decimal import Decimal
+        from .crud import get_account_by_name, get_or_create_user_account
+        from .models import AccountType
+        from .beancount_format import format_net_settlement_entry
+
+        # Convert amount from millisatoshis to satoshis
+        amount_sats = payment.amount // 1000
+
+        # Extract fiat metadata from invoice (if present)
+        fiat_currency = None
+        fiat_amount = None
+        if payment.extra:
+            fiat_currency = payment.extra.get("fiat_currency")
+            fiat_amount_str = payment.extra.get("fiat_amount")
+            if fiat_amount_str:
+                fiat_amount = Decimal(str(fiat_amount_str))
+
+        if not fiat_currency or not fiat_amount:
+            logger.error(f"Payment {payment.payment_hash} missing fiat currency/amount metadata")
+            return
+
+        # Get user's current balance to determine receivables and payables
+        balance = await fava.get_user_balance(user_id)
+        fiat_balances = balance.get("fiat_balances", {})
+        total_fiat_balance = fiat_balances.get(fiat_currency, Decimal(0))
+
+        # Determine receivables and payables based on balance
+        # Positive balance = user owes castle (receivable)
+        # Negative balance = castle owes user (payable)
+        if total_fiat_balance > 0:
+            # User owes castle
+            total_receivable = total_fiat_balance
+            total_payable = Decimal(0)
+        else:
+            # Castle owes user
+            total_receivable = Decimal(0)
+            total_payable = abs(total_fiat_balance)
+
+        logger.info(f"Settlement: {fiat_amount} {fiat_currency} (Receivable: {total_receivable}, Payable: {total_payable})")
+
+        # Get account names
+        user_receivable = await get_or_create_user_account(
+            user_id, AccountType.ASSET, "Accounts Receivable"
+        )
+        user_payable = await get_or_create_user_account(
+            user_id, AccountType.LIABILITY, "Accounts Payable"
+        )
+        lightning_account = await get_account_by_name("Assets:Bitcoin:Lightning")
+        if not lightning_account:
+            logger.error("Lightning account 'Assets:Bitcoin:Lightning' not found")
+            return
+
+        # Query for unsettled entries to link this settlement back to them
+        # Net settlement can settle both expenses and receivables
+        settled_links = []
         try:
-            from decimal import Decimal
-            from .crud import get_account_by_name, get_or_create_user_account
-            from .models import AccountType
-            from .beancount_format import format_net_settlement_entry
-
-            # Convert amount from millisatoshis to satoshis
-            amount_sats = payment.amount // 1000
-
-            # Extract fiat metadata from invoice (if present)
-            fiat_currency = None
-            fiat_amount = None
-            if payment.extra:
-                fiat_currency = payment.extra.get("fiat_currency")
-                fiat_amount_str = payment.extra.get("fiat_amount")
-                if fiat_amount_str:
-                    fiat_amount = Decimal(str(fiat_amount_str))
-
-            if not fiat_currency or not fiat_amount:
-                logger.error(f"Payment {payment.payment_hash} missing fiat currency/amount metadata")
-                return
-
-            # Get user's current balance to determine receivables and payables
-            balance = await fava.get_user_balance(user_id)
-            fiat_balances = balance.get("fiat_balances", {})
-            total_fiat_balance = fiat_balances.get(fiat_currency, Decimal(0))
-
-            # Determine receivables and payables based on balance
-            # Positive balance = user owes castle (receivable)
-            # Negative balance = castle owes user (payable)
-            if total_fiat_balance > 0:
-                # User owes castle
-                total_receivable = total_fiat_balance
-                total_payable = Decimal(0)
-            else:
-                # Castle owes user
-                total_receivable = Decimal(0)
-                total_payable = abs(total_fiat_balance)
-
-            logger.info(f"Settlement: {fiat_amount} {fiat_currency} (Receivable: {total_receivable}, Payable: {total_payable})")
-
-            # Get account names
-            user_receivable = await get_or_create_user_account(
-                user_id, AccountType.ASSET, "Accounts Receivable"
-            )
-            user_payable = await get_or_create_user_account(
-                user_id, AccountType.LIABILITY, "Accounts Payable"
-            )
-            lightning_account = await get_account_by_name("Assets:Bitcoin:Lightning")
-            if not lightning_account:
-                logger.error("Lightning account 'Assets:Bitcoin:Lightning' not found")
-                return
-
-            # Query for unsettled entries to link this settlement back to them
-            # Net settlement can settle both expenses and receivables
-            settled_links = []
-            try:
-                unsettled_expenses = await fava.get_unsettled_entries_bql(user_id, "expense")
-                settled_links.extend([e["link"] for e in unsettled_expenses if e.get("link")])
-                unsettled_receivables = await fava.get_unsettled_entries_bql(user_id, "receivable")
-                settled_links.extend([e["link"] for e in unsettled_receivables if e.get("link")])
-            except Exception as e:
-                logger.warning(f"Could not query unsettled entries for settlement links: {e}")
-                # Continue without links - settlement will still be recorded
-
-            # Format as net settlement transaction
-            entry = format_net_settlement_entry(
-                user_id=user_id,
-                payment_account=lightning_account.name,
-                receivable_account=user_receivable.name,
-                payable_account=user_payable.name,
-                amount_sats=amount_sats,
-                net_fiat_amount=fiat_amount,
-                total_receivable_fiat=total_receivable,
-                total_payable_fiat=total_payable,
-                fiat_currency=fiat_currency,
-                description=f"Lightning payment settlement from user {user_id[:8]}",
-                entry_date=datetime.now().date(),
-                payment_hash=payment.payment_hash,
-                reference=payment.payment_hash,
-                settled_entry_links=settled_links if settled_links else None
-            )
-
-            # Submit to Fava using idempotent method to prevent duplicates
-            # The idempotency key is based on the payment hash, so even if this
-            # function is called multiple times for the same payment, only one
-            # entry will be created
-            result = await fava.add_entry_idempotent(entry, idempotency_key)
-
-            if result.get("existing"):
-                logger.info(
-                    f"Payment {payment.payment_hash} was already recorded in Fava (idempotent)"
-                )
-            else:
-                logger.info(
-                    f"Successfully recorded payment {payment.payment_hash} to Fava: "
-                    f"{result.get('data', 'Unknown')}"
-                )
-
+            unsettled_expenses = await fava.get_unsettled_entries_bql(user_id, "expense")
+            settled_links.extend([e["link"] for e in unsettled_expenses if e.get("link")])
+            unsettled_receivables = await fava.get_unsettled_entries_bql(user_id, "receivable")
+            settled_links.extend([e["link"] for e in unsettled_receivables if e.get("link")])
         except Exception as e:
-            logger.error(f"Error recording Castle payment {payment.payment_hash}: {e}")
-            raise
+            logger.warning(f"Could not query unsettled entries for settlement links: {e}")
+            # Continue without links - settlement will still be recorded
+
+        # Format as net settlement transaction
+        entry = format_net_settlement_entry(
+            user_id=user_id,
+            payment_account=lightning_account.name,
+            receivable_account=user_receivable.name,
+            payable_account=user_payable.name,
+            amount_sats=amount_sats,
+            net_fiat_amount=fiat_amount,
+            total_receivable_fiat=total_receivable,
+            total_payable_fiat=total_payable,
+            fiat_currency=fiat_currency,
+            description=f"Lightning payment settlement from user {user_id[:8]}",
+            entry_date=datetime.now().date(),
+            payment_hash=payment.payment_hash,
+            reference=payment.payment_hash,
+            settled_entry_links=settled_links if settled_links else None
+        )
+
+        # Submit to Fava
+        result = await fava.add_entry(entry)
+
+        logger.info(
+            f"Successfully recorded payment {payment.payment_hash} to Fava: "
+            f"{result.get('data', 'Unknown')}"
+        )
+
+    except Exception as e:
+        logger.error(f"Error recording Castle payment {payment.payment_hash}: {e}")
+        raise
diff --git a/templates/castle/index.html b/templates/castle/index.html
index 2a1e665..6648e6c 100644
--- a/templates/castle/index.html
+++ b/templates/castle/index.html
@@ -17,14 +17,13 @@
             <p class="q-mb-none">Track expenses, receivables, and balances for the collective</p>
           </div>
           <div class="col-auto q-gutter-xs">
-            <!-- Wait for settings to load before showing role-specific buttons to prevent race conditions -->
-            <q-btn v-if="settingsLoaded && !isSuperUser" flat round icon="account_balance_wallet" @click="showUserWalletDialog">
+            <q-btn v-if="!isSuperUser" flat round icon="account_balance_wallet" @click="showUserWalletDialog">
               <q-tooltip>Configure Your Wallet</q-tooltip>
             </q-btn>
-            <q-btn v-if="settingsLoaded && isSuperUser" flat round icon="admin_panel_settings" :href="'/castle/permissions'">
+            <q-btn v-if="isSuperUser" flat round icon="admin_panel_settings" :href="'/castle/permissions'">
               <q-tooltip>Manage Permissions (Admin)</q-tooltip>
             </q-btn>
-            <q-btn v-if="settingsLoaded && isSuperUser" flat round icon="settings" @click="showSettingsDialog">
+            <q-btn v-if="isSuperUser" flat round icon="settings" @click="showSettingsDialog">
               <q-tooltip>Castle Settings (Super User Only)</q-tooltip>
             </q-btn>
           </div>
@@ -33,7 +32,7 @@
     </q-card>
 
     <!-- Setup Warning -->
-    <q-banner v-if="settingsLoaded && !castleWalletConfigured && isSuperUser" class="bg-warning text-white" rounded>
+    <q-banner v-if="!castleWalletConfigured && isSuperUser" class="bg-warning text-white" rounded>
       <template v-slot:avatar>
         <q-icon name="warning" color="white"></q-icon>
       </template>
@@ -45,7 +44,7 @@
       </template>
     </q-banner>
 
-    <q-banner v-if="settingsLoaded && !castleWalletConfigured && !isSuperUser" class="bg-info text-white" rounded>
+    <q-banner v-if="!castleWalletConfigured && !isSuperUser" class="bg-info text-white" rounded>
       <template v-slot:avatar>
         <q-icon name="info" color="white"></q-icon>
       </template>
@@ -54,7 +53,7 @@
       </div>
     </q-banner>
 
-    <q-banner v-if="settingsLoaded && castleWalletConfigured && !userWalletConfigured && !isSuperUser" class="bg-orange text-white" rounded>
+    <q-banner v-if="castleWalletConfigured && !userWalletConfigured && !isSuperUser" class="bg-orange text-white" rounded>
       <template v-slot:avatar>
         <q-icon name="account_balance_wallet" color="white"></q-icon>
       </template>
@@ -1123,46 +1122,10 @@
         :disable="!isSuperUser"
       ></q-select>
 
-      <div class="text-caption text-grey q-mb-md">
+      <div class="text-caption text-grey">
         Select the wallet that will be used for Castle operations and transactions.
       </div>
 
-      <q-separator class="q-my-md"></q-separator>
-
-      <div class="text-subtitle2 q-mb-sm">Fava/Beancount Integration</div>
-
-      <q-input
-        filled
-        dense
-        v-model="settingsDialog.favaUrl"
-        label="Fava URL *"
-        hint="Base URL of the Fava server (e.g., http://localhost:3333)"
-        :readonly="!isSuperUser"
-        :disable="!isSuperUser"
-      ></q-input>
-
-      <q-input
-        filled
-        dense
-        v-model="settingsDialog.favaLedgerSlug"
-        label="Ledger Slug"
-        hint="Ledger identifier in Fava URL (e.g., castle-ledger)"
-        :readonly="!isSuperUser"
-        :disable="!isSuperUser"
-      ></q-input>
-
-      <q-input
-        filled
-        dense
-        type="number"
-        step="0.5"
-        v-model.number="settingsDialog.favaTimeout"
-        label="Timeout (seconds)"
-        hint="Request timeout for Fava API calls"
-        :readonly="!isSuperUser"
-        :disable="!isSuperUser"
-      ></q-input>
-
       <div class="row q-mt-lg">
         <q-btn
           v-if="isSuperUser"
diff --git a/views_api.py b/views_api.py
index 594b26b..77eadaf 100644
--- a/views_api.py
+++ b/views_api.py
@@ -2113,7 +2113,7 @@ async def api_pay_user(
     if "meta" not in entry:
         entry["meta"] = {}
     entry["meta"]["payment-method"] = data.payment_method
-    entry["meta"]["paid-by"] = auth.user_id
+    entry["meta"]["paid-by"] = wallet.wallet.user
     if data.txid:
         entry["meta"]["txid"] = data.txid
 
@@ -2174,24 +2174,10 @@ async def api_get_user_wallet(
     user_id: str,
     auth: AuthContext = Depends(require_super_user),
 ) -> dict:
-    """Get user's wallet settings (super user only)
+    """Get user's wallet settings (super user only)"""
 
-    Supports both full UUIDs and truncated 8-char IDs (from Beancount accounts).
-    """
-    from .crud import get_user_wallet_settings_by_prefix
-
-    # First try exact match
     user_wallet = await get_user_wallet(user_id)
-
-    # If not found and user_id looks like a truncated ID (8 chars), try prefix match
-    if not user_wallet or not user_wallet.user_wallet_id:
-        if len(user_id) <= 8:
-            stored_wallet = await get_user_wallet_settings_by_prefix(user_id)
-            if stored_wallet and stored_wallet.user_wallet_id:
-                user_wallet = stored_wallet
-                user_id = stored_wallet.id  # Use the full ID
-
-    if not user_wallet or not user_wallet.user_wallet_id:
+    if not user_wallet:
         return {"user_id": user_id, "user_wallet_id": None}
 
     # Get invoice key for the user's wallet (needed to generate invoices)
@@ -2650,7 +2636,6 @@ async def api_approve_expense_entry(
 
     This updates the transaction in the Beancount file via Fava API.
     """
-    import httpx
     from .fava_client import get_fava_client
 
     fava = get_fava_client()
@@ -2659,6 +2644,7 @@ async def api_approve_expense_entry(
     all_entries = await fava.get_journal_entries()
 
     # 2. Find the entry with matching castle ID in links
+    target_entry_hash = None
     target_entry = None
 
     for entry in all_entries:
@@ -2670,86 +2656,51 @@ async def api_approve_expense_entry(
                 link_clean = link.lstrip('^')
                 # Check if this entry has our castle ID
                 if link_clean == f"castle-{entry_id}" or link_clean.endswith(f"-{entry_id}"):
+                    target_entry_hash = entry.get("entry_hash")
                     target_entry = entry
                     break
-            if target_entry:
+            if target_entry_hash:
                 break
 
-    if not target_entry:
+    if not target_entry_hash:
         raise HTTPException(
             status_code=HTTPStatus.NOT_FOUND,
             detail=f"Pending entry {entry_id} not found in Beancount ledger"
         )
 
-    # Get entry metadata for file location
-    meta = target_entry.get("meta", {})
-    filename = meta.get("filename")
-    lineno = meta.get("lineno")
-    date_str = target_entry.get("date", "")
+    # 3. Get the entry context (source text + sha256sum)
+    context = await fava.get_entry_context(target_entry_hash)
+    source = context.get("slice", "")
+    sha256sum = context.get("sha256sum", "")
 
-    if not filename or not lineno:
+    if not source:
         raise HTTPException(
             status_code=HTTPStatus.INTERNAL_SERVER_ERROR,
-            detail="Entry metadata missing filename or lineno"
+            detail="Could not retrieve entry source from Fava"
         )
 
-    # 3. Get the source file from Fava
-    async with httpx.AsyncClient(timeout=fava.timeout) as client:
-        response = await client.get(
-            f"{fava.base_url}/source",
-            params={"filename": filename}
+    # 4. Change flag from ! to *
+    # Replace the first occurrence of the date + ! pattern
+    import re
+    date_str = target_entry.get("date", "")
+    old_pattern = f"{date_str} !"
+    new_pattern = f"{date_str} *"
+
+    if old_pattern not in source:
+        raise HTTPException(
+            status_code=HTTPStatus.INTERNAL_SERVER_ERROR,
+            detail=f"Could not find pending flag pattern '{old_pattern}' in entry source"
         )
-        response.raise_for_status()
-        source_data = response.json()["data"]
 
-        sha256sum = source_data["sha256sum"]
-        source = source_data["source"]
-        lines = source.split('\n')
+    new_source = source.replace(old_pattern, new_pattern, 1)
 
-        # 4. Find and modify the entry at the specified line
-        # Line numbers are 1-indexed, list is 0-indexed
-        entry_line_idx = lineno - 1
-
-        if entry_line_idx >= len(lines):
-            raise HTTPException(
-                status_code=HTTPStatus.INTERNAL_SERVER_ERROR,
-                detail=f"Line {lineno} not found in source file"
-            )
-
-        entry_line = lines[entry_line_idx]
-
-        # Check if the line contains the pending flag pattern
-        old_pattern = f"{date_str} !"
-        if old_pattern not in entry_line:
-            raise HTTPException(
-                status_code=HTTPStatus.INTERNAL_SERVER_ERROR,
-                detail=f"Line {lineno} does not contain expected pattern '{old_pattern}'. Found: {entry_line}"
-            )
-
-        # Replace the flag
-        new_pattern = f"{date_str} *"
-        new_line = entry_line.replace(old_pattern, new_pattern, 1)
-        lines[entry_line_idx] = new_line
-
-        # 5. Write back the modified source
-        new_source = '\n'.join(lines)
-
-        update_response = await client.put(
-            f"{fava.base_url}/source",
-            json={
-                "file_path": filename,
-                "source": new_source,
-                "sha256sum": sha256sum
-            },
-            headers={"Content-Type": "application/json"}
-        )
-        update_response.raise_for_status()
-
-    logger.info(f"Entry {entry_id} approved (flag changed to *)")
+    # 5. Update the entry via Fava API
+    await fava.update_entry_source(target_entry_hash, new_source, sha256sum)
 
     return {
         "message": f"Entry {entry_id} approved successfully",
         "entry_id": entry_id,
+        "entry_hash": target_entry_hash,
         "date": date_str,
         "description": target_entry.get("narration", "")
     }
@@ -2766,7 +2717,6 @@ async def api_reject_expense_entry(
     Adds #voided tag for audit trail while keeping the '!' flag.
     Voided transactions are excluded from balances but preserved in the ledger.
     """
-    import httpx
     from .fava_client import get_fava_client
 
     fava = get_fava_client()
@@ -2775,6 +2725,7 @@ async def api_reject_expense_entry(
     all_entries = await fava.get_journal_entries()
 
     # 2. Find the entry with matching castle ID in links
+    target_entry_hash = None
     target_entry = None
 
     for entry in all_entries:
@@ -2786,77 +2737,58 @@ async def api_reject_expense_entry(
                 link_clean = link.lstrip('^')
                 # Check if this entry has our castle ID
                 if link_clean == f"castle-{entry_id}" or link_clean.endswith(f"-{entry_id}"):
+                    target_entry_hash = entry.get("entry_hash")
                     target_entry = entry
                     break
-            if target_entry:
+            if target_entry_hash:
                 break
 
-    if not target_entry:
+    if not target_entry_hash:
         raise HTTPException(
             status_code=HTTPStatus.NOT_FOUND,
             detail=f"Pending entry {entry_id} not found in Beancount ledger"
         )
 
-    # Get entry metadata for file location
-    meta = target_entry.get("meta", {})
-    filename = meta.get("filename")
-    lineno = meta.get("lineno")
-    date_str = target_entry.get("date", "")
+    # 3. Get the entry context (source text + sha256sum)
+    context = await fava.get_entry_context(target_entry_hash)
+    source = context.get("slice", "")
+    sha256sum = context.get("sha256sum", "")
 
-    if not filename or not lineno:
+    if not source:
         raise HTTPException(
             status_code=HTTPStatus.INTERNAL_SERVER_ERROR,
-            detail="Entry metadata missing filename or lineno"
+            detail="Could not retrieve entry source from Fava"
         )
 
-    # 3. Get the source file from Fava
-    async with httpx.AsyncClient(timeout=fava.timeout) as client:
-        response = await client.get(
-            f"{fava.base_url}/source",
-            params={"filename": filename}
-        )
-        response.raise_for_status()
-        source_data = response.json()["data"]
+    # 4. Add #voided tag (keep ! flag as per convention)
+    date_str = target_entry.get("date", "")
 
-        sha256sum = source_data["sha256sum"]
-        source = source_data["source"]
+    # Add #voided tag if not already present
+    if "#voided" not in source:
+        # Find the transaction line and add #voided to the tags
+        # Pattern: date ! "narration" #existing-tags
         lines = source.split('\n')
+        for i, line in enumerate(lines):
+            if date_str in line and '"' in line and '!' in line:
+                # Add #voided tag to the transaction line
+                if '#' in line:
+                    # Already has tags, append voided
+                    lines[i] = line.rstrip() + ' #voided'
+                else:
+                    # No tags yet, add after narration
+                    lines[i] = line.rstrip() + ' #voided'
+                break
+        new_source = '\n'.join(lines)
+    else:
+        new_source = source
 
-        # 4. Find and modify the entry at the specified line - add #voided tag
-        entry_line_idx = lineno - 1
-
-        if entry_line_idx >= len(lines):
-            raise HTTPException(
-                status_code=HTTPStatus.INTERNAL_SERVER_ERROR,
-                detail=f"Line {lineno} not found in source file"
-            )
-
-        entry_line = lines[entry_line_idx]
-
-        # Add #voided tag if not already present
-        if "#voided" not in entry_line:
-            # Add #voided tag to the transaction line
-            new_line = entry_line.rstrip() + ' #voided'
-            lines[entry_line_idx] = new_line
-
-            # 5. Write back the modified source
-            new_source = '\n'.join(lines)
-
-            update_response = await client.put(
-                f"{fava.base_url}/source",
-                json={
-                    "file_path": filename,
-                    "source": new_source,
-                    "sha256sum": sha256sum
-                },
-                headers={"Content-Type": "application/json"}
-            )
-            update_response.raise_for_status()
-            logger.info(f"Entry {entry_id} rejected (added #voided tag)")
+    # 5. Update the entry via Fava API
+    await fava.update_entry_source(target_entry_hash, new_source, sha256sum)
 
     return {
         "message": f"Entry {entry_id} rejected (marked as voided)",
         "entry_id": entry_id,
+        "entry_hash": target_entry_hash,
         "date": date_str,
         "description": target_entry.get("narration", "")
     }