diff --git a/optlib/api.py b/optlib/api.py
index e69de29..958d115 100644
--- a/optlib/api.py
+++ b/optlib/api.py
@@ -0,0 +1,50 @@
+import subprocess
+import json
+
+ENDPOINT = "https://api.tdameritrade.com/v1/marketdata/chains"
+
+# ------------------------------
+# This class defines the Exception that gets thrown when the api input is bad.
+class API_InputError(Exception):
+    def __init__(self, mismatch):
+        Exception.__init__(self, mismatch)
+
+# ------------------------------
+# This function verifies that the required apikey and symbol arguments are provided.
+def _test_input(*args, **kwargs):
+    if ("apikey" not in kwargs.keys()) or ("symbol" not in kwargs.keys()):
+        raise API_InputError("Bad input. `apikey` and `symbol` are required.")
+
+def get(*args, **kwargs):
+    """Request an option chain from TDAmeritrade's API.
+
+    Args:
+        apikey (str):            API key to api.tdameritrade.com.
+        symbol (str):            Stock symbol to get the option chain for.
+        contractType (str):      Type of contracts to return in the chain. Can be CALL, PUT, or ALL. Default is ALL.
+        strikeCount (int):       The number of strikes to return above and below the at-the-money price.
+        includeQuotes (str):     Include quotes for options in the option chain. Can be TRUE or FALSE. Default is FALSE.
+        strategy (str):          Passing a value returns a Strategy Chain. Default is SINGLE.
+        interval (int):          Strike interval for spread strategy chains.
+        strike (int):            Provide a strike price to return options only at that strike price.
+        range (str):             Returns options for the given range. Default is ALL.
+        fromDate (str):          Only return expirations after this date.
+        toDate (str):            Only return expirations before this date.
+        volatility (float):      Volatility to use in calculations. Applies only to ANALYTICAL strategy chains.
+        underlyingPrice (float): Underlying price to use in calculations. Applies only to ANALYTICAL strategy chains.
+        interestRate (float):    Interest rate to use in calculations. Applies only to ANALYTICAL strategy chains.
+        daysToExpiration (int):  Days to expiration to use in calculations. Applies only to ANALYTICAL strategy chains.
+        expMonth (str):          Return only options expiring in the specified month. Example: JAN. Default is ALL.
+        optionType (str):        Type of contracts to return. Default is ALL.
+
+    Returns:
+        resp (dict): API response with option chain.
+    """
+    _test_input(*args, **kwargs)
+
+    url = "?".join([ENDPOINT, "&".join(f"{k}={v}" for k, v in kwargs.items())])
+    resp = json.loads(subprocess.check_output(["curl", "-gs", url]))
+    if resp.get("error"):
+        raise API_InputError("Bad query. Contains unknown query parameters.")
+
+    return resp