community: Add stock market tools from financialdatasets.ai (#25025)

**Description:**
In this PR, I am adding three stock market tools from
financialdatasets.ai (my API!):
- get balance sheets
- get cash flow statements
- get income statements

Twitter handle: [@virattt](https://twitter.com/virattt)

---------

Co-authored-by: Erick Friis <erick@langchain.dev>

libs/community/langchain_community/utilities/financial_datasets.py

@@ -0,0 +1,135 @@
+"""
+Util that calls several of financial datasets stock market REST APIs.
+Docs: https://docs.financialdatasets.ai/
+"""
+
+import json
+from typing import Any, List, Optional
+
+import requests
+from langchain_core.pydantic_v1 import BaseModel
+from langchain_core.utils import get_from_dict_or_env
+
+FINANCIAL_DATASETS_BASE_URL = "https://api.financialdatasets.ai/"
+
+
+class FinancialDatasetsAPIWrapper(BaseModel):
+    """Wrapper for financial datasets API."""
+
+    financial_datasets_api_key: Optional[str] = None
+
+    def __init__(self, **data: Any):
+        super().__init__(**data)
+        self.financial_datasets_api_key = get_from_dict_or_env(
+            data, "financial_datasets_api_key", "FINANCIAL_DATASETS_API_KEY"
+        )
+
+    def get_income_statements(
+        self,
+        ticker: str,
+        period: str,
+        limit: Optional[int],
+    ) -> Optional[dict]:
+        """
+        Get the income statements for a stock `ticker` over a `period` of time.
+
+        :param ticker: the stock ticker
+        :param period: the period of time to get the balance sheets for.
+            Possible values are: annual, quarterly, ttm.
+        :param limit: the number of results to return, default is 10
+        :return: a list of income statements
+        """
+        url = (
+            f"{FINANCIAL_DATASETS_BASE_URL}financials/income-statements/"
+            f"?ticker={ticker}"
+            f"&period={period}"
+            f"&limit={limit if limit else 10}"
+        )
+
+        # Add the api key to the headers
+        headers = {"X-API-KEY": self.financial_datasets_api_key}
+
+        # Execute the request
+        response = requests.get(url, headers=headers)
+        data = response.json()
+
+        return data.get("income_statements", None)
+
+    def get_balance_sheets(
+        self,
+        ticker: str,
+        period: str,
+        limit: Optional[int],
+    ) -> List[dict]:
+        """
+        Get the balance sheets for a stock `ticker` over a `period` of time.
+
+        :param ticker: the stock ticker
+        :param period: the period of time to get the balance sheets for.
+            Possible values are: annual, quarterly, ttm.
+        :param limit: the number of results to return, default is 10
+        :return: a list of balance sheets
+        """
+        url = (
+            f"{FINANCIAL_DATASETS_BASE_URL}financials/balance-sheets/"
+            f"?ticker={ticker}"
+            f"&period={period}"
+            f"&limit={limit if limit else 10}"
+        )
+
+        # Add the api key to the headers
+        headers = {"X-API-KEY": self.financial_datasets_api_key}
+
+        # Execute the request
+        response = requests.get(url, headers=headers)
+        data = response.json()
+
+        return data.get("balance_sheets", None)
+
+    def get_cash_flow_statements(
+        self,
+        ticker: str,
+        period: str,
+        limit: Optional[int],
+    ) -> List[dict]:
+        """
+        Get the cash flow statements for a stock `ticker` over a `period` of time.
+
+        :param ticker: the stock ticker
+        :param period: the period of time to get the balance sheets for.
+            Possible values are: annual, quarterly, ttm.
+        :param limit: the number of results to return, default is 10
+        :return: a list of cash flow statements
+        """
+
+        url = (
+            f"{FINANCIAL_DATASETS_BASE_URL}financials/cash-flow-statements/"
+            f"?ticker={ticker}"
+            f"&period={period}"
+            f"&limit={limit if limit else 10}"
+        )
+
+        # Add the api key to the headers
+        headers = {"X-API-KEY": self.financial_datasets_api_key}
+
+        # Execute the request
+        response = requests.get(url, headers=headers)
+        data = response.json()
+
+        return data.get("cash_flow_statements", None)
+
+    def run(self, mode: str, ticker: str, **kwargs: Any) -> str:
+        if mode == "get_income_statements":
+            period = kwargs.get("period", "annual")
+            limit = kwargs.get("limit", 10)
+            return json.dumps(self.get_income_statements(ticker, period, limit))
+        elif mode == "get_balance_sheets":
+            period = kwargs.get("period", "annual")
+            limit = kwargs.get("limit", 10)
+            return json.dumps(self.get_balance_sheets(ticker, period, limit))
+        elif mode == "get_cash_flow_statements":
+            period = kwargs.get("period", "annual")
+            limit = kwargs.get("limit", 10)
+            return json.dumps(self.get_cash_flow_statements(ticker, period, limit))
+        else:
+            raise ValueError(f"Invalid mode {mode} for financial datasets API.")