add plaid link endpoints

plaid_client.py

@@ -1,8 +1,129 @@
+import os
+from datetime import date, timedelta
+from plaid.api import plaid_api
+from plaid.configuration import Configuration
+from plaid.api_client import ApiClient
+from plaid.model.products import Products
+from plaid.model.country_code import CountryCode
+from plaid.model.accounts_balance_get_request import AccountsBalanceGetRequest
+from plaid.model.transactions_get_request import TransactionsGetRequest
+from plaid.model.transactions_get_request_options import TransactionsGetRequestOptions
 from plaid.model.link_token_create_request import LinkTokenCreateRequest
 from plaid.model.link_token_create_request_user import LinkTokenCreateRequestUser
 from plaid.model.item_public_token_exchange_request import ItemPublicTokenExchangeRequest
 
+# ---------- Client setup ----------
+
+def _make_client():
+    env = os.environ.get("PLAID_ENV", "sandbox")
+    host = {
+        "sandbox":     "https://sandbox.plaid.com",
+        "development": "https://development.plaid.com",
+        "production":  "https://production.plaid.com",
+    }[env]
+
+    config = Configuration(
+        host=host,
+        api_key={
+        "clientId": os.environ["PLAID_CLIENT_ID"],   # reads from .env
+        "secret":   os.environ["PLAID_SECRET"]
+        }
+    )
+    return plaid_api.PlaidApi(ApiClient(config))
+
+plaid_client = _make_client()
+
+
+# ---------- Balances ----------
+
+def get_balances(access_token: str) -> str:
+    """Returns formatted balance snapshot for the LLM prompt."""
+    request = AccountsBalanceGetRequest(access_token=access_token)
+    response = plaid_client.accounts_balance_get(request)
+
+    lines = ["USER'S CURRENT ACCOUNT BALANCES:"]
+    for account in response['accounts']:
+        name     = account['name']
+        subtype  = account['subtype']       # 'checking', 'credit card', etc.
+        current  = account['balances']['current']
+        
+        if subtype == 'credit card':
+            limit     = account['balances']['limit'] or 0
+            available = account['balances']['available'] or (limit - current)
+            lines.append(
+                f"- {name} (Visa/Credit): "
+                f"${current:.2f} owing, ${available:.2f} available"
+            )
+        else:
+            lines.append(f"- {name} (Chequing): ${current:.2f}")
+
+    return "\n".join(lines)
+
+
+# ---------- Transactions ----------
+
+def get_transactions(access_token: str, days: int = 30) -> str:
+    """Returns formatted transaction summary for the LLM prompt."""
+    end_date   = date.today()
+    start_date = end_date - timedelta(days=days)
+
+    request = TransactionsGetRequest(
+        access_token=access_token,
+        start_date=start_date,
+        end_date=end_date,
+        options=TransactionsGetRequestOptions(
+            count=100,
+            include_personal_finance_category=True
+        )
+    )
+    response = plaid_client.transactions_get(request)
+    transactions = response['transactions']
+
+    if not transactions:
+        return "No transactions found in the last 30 days."
+
+    # Python does the math — never let the LLM calculate
+    category_totals: dict[str, float] = {}
+    for txn in transactions:
+        if txn['amount'] <= 0:
+            continue   # skip deposits/refunds
+        category = txn.get('personal_finance_category', {}).get('primary', 'OTHER')
+        category_totals[category] = category_totals.get(category, 0) + txn['amount']
+
+    # Format for prompt
+    lines = [f"SPENDING SUMMARY (last {days} days):"]
+    for category, total in sorted(category_totals.items(), key=lambda x: -x[1]):
+        readable = category.replace("_", " ").title()
+        lines.append(f"- {readable}: ${total:.2f}")
+
+    lines.append(f"\nTotal spent: ${sum(category_totals.values()):.2f}")
+    lines.append(f"\nRECENT TRANSACTIONS (last 10):")
+    for txn in transactions[:10]:
+        lines.append(
+            f"- {txn['date']}  {txn['name']:<30}  ${txn['amount']:.2f}"
+        )
+
+    return "\n".join(lines)
+
+
+# ---------- Combined snapshot ----------
+
+def get_financial_snapshot(access_token: str) -> str:
+    """
+    Returns full financial context string to inject into the LLM prompt.
+    Combines balances + transaction summary.
+    """
+    try:
+        balances     = get_balances(access_token)
+        transactions = get_transactions(access_token)
+        return f"{balances}\n\n{transactions}"
+    except Exception as e:
+        return f"Unable to fetch account data: {str(e)}"
+
+
+
 def create_link_token(user_id: str) -> str:
+    """Creates a Plaid Link token for the given user."""
     request = LinkTokenCreateRequest(
         user=LinkTokenCreateRequestUser(client_user_id=user_id),
         client_name="FISCAL",
@@ -14,6 +135,7 @@ def create_link_token(user_id: str) -> str:
     return response["link_token"]
 
 def exchange_public_token(public_token: str) -> str:
+    """Exchanges a public token for a permanent access token."""
     request = ItemPublicTokenExchangeRequest(public_token=public_token)
     response = plaid_client.item_public_token_exchange(request)
     return response["access_token"]