All values in the addSymbols response and tick/bar events arrive as strings, not numbers. Always use parseFloat() or parseInt() before doing math or comparisons.

const ltp = data[2];
// "1332.9" — math/comparison fails

const ltp = parseFloat(data[2]);
// 1332.9

Always pass the symbol name string, e.g. "RELIANCE", "NIFTY 50". Never pass numeric symbolIds.

await TD.Feed.addSymbols([100001262]);

await TD.Feed.addSymbols(["RELIANCE"]);

addSymbols, removeSymbols, setCell, setCellRange, getCell, getCellRange are all async. Missing await causes race conditions and unpredictable behavior.

TD.Feed.addSymbols(["RELIANCE"]);

await TD.Feed.addSymbols(["RELIANCE"]);

In the tick event, data[0] is the symbolId (e.g. "100001262"), NOT the symbol name. To match by name, build a lookup map during onStart.

if (data[0] === "RELIANCE") { ... }
// data[0] is "100001262", not the name

const symbolMap = {}; // { symbolId: symbolName }

TD.onStart = async () => {
  const response = await TD.Feed.addSymbols(["RELIANCE"]);
  for (const sym of response.symbollist) {
    symbolMap[sym[1]] = sym[0];
  }
};

TD.on("tick", (data) => {
  const name = symbolMap[data[0]]; // "RELIANCE"
});

The response has the shape { success, message, symbollist }. Access response.symbollist[0], not response[0].

const data = response[0]; // undefined

const data = response.symbollist[0];

If the symbol name is invalid or the feed fails, success is false and symbollist is empty. Accessing symbollist[0] without checking will crash.

const response = await TD.Feed.addSymbols(["RELIANCE"]);
if (!response.success) {
  TD.log("Subscribe failed: " + response.message);
  return;
}
const data = response.symbollist[0];

Event listeners must be at the top level of the script — not inside onStart, onStop, or any function.

TD.onStart = async () => {
  TD.on("tick", (data) => { ... });
  // inside a hook — wrong
};

TD.on("tick", (data) => { ... }); // top level

TD.onStart = async () => {
  await TD.Feed.addSymbols(["RELIANCE"]);
};

Every symbol subscribed in onStart must be unsubscribed in onStop to avoid memory leaks.

TD.onStop = async () => {
  await TD.Feed.removeSymbols(["RELIANCE", "NIFTY 50"]);
};

Do not use or invent other Sheet methods. The only available ones are setCell, setCellRange, getCell, getCellRange. See Sheet Read / Write for full usage.

TD.Analytics.* and TD.Historical.* are async and must be awaited inside TD.onStart, or an async function called from it.

Subscribe using the full TD option symbol format: "NIFTY26062323500CE" (symbol + YYMMDD + strike + CE/PE). Do not pass the base symbol like "NIFTY" or "NIFTY 50".

await TD.Feed.addSymbols(["NIFTY"]);
// base symbol won't produce greeks

await TD.Feed.addSymbols(["NIFTY26062323500CE"]);

The option chain API needs the mapped short symbol, not the display name. This mapping applies only to these five indices — every other symbol (e.g. "RELIANCE") passes through unchanged.

await TD.OptionChain.getOptionChain({
  symbol: "NIFTY 50",
  expiry: "23-06-2026",
});
// "NIFTY BANK" / "BANK NIFTY" also wrong

await TD.OptionChain.getOptionChain({
  symbol: "NIFTY",
  expiry: "23-06-2026",
});

Always pass expiry in "DD-MM-YYYY" format, e.g. "23-06-2026".

These Historical functions use different segment strings than Analytics functions. Do not use "EQ" here.

await TD.Historical.getTopNGainers({
  segment: "EQ", topn: 5
});

await TD.Historical.getTopNGainers({
  segment: "NSEEQ", topn: 5
});

Always wrap async calls in try/catch and log errors via TD.log().

TD.onStart = async () => {
  try {
    const response = await TD.Feed.addSymbols(["RELIANCE"]);
    if (!response.success) throw new Error(response.message);
  } catch (err) {
    TD.log("Error: " + err.message);
  }
};

In Historical, Analytics, and Option Chain responses, records[0] is always the header row. Data rows start at records[1]. Never process records[0] as data.

const records = data.records;
const headers = records[0]; // header row — skip this
for (let i = 1; i < records.length; i++) {
  const row = records[i]; // actual data
}