Indicators›Support, resistance & structure›TD Lines

GET/indicator/tdlines

TD Lines

Category: Support, resistance & structure · Updated November 2026

The TAAPI.IO TD Lines API returns open, high, low, close values for the TD Lines indicator as JSON, for crypto pairs and US stocks. Send an exchange, symbol and timeframe to get real-time or historical data, with no candles to download and no calculations to maintain.

Spec	Value
Endpoint	`GET https://v2.taapi.io/indicator/tdlines`
Outputs	`open`, `high`, `low`, `close`, `tdHigh`, `tdLow`
Markets	Binance, Binance Futures, Bybit, Gate.io, Kraken and US stocks
Timeframes	`1m` to `1w`
Delivery	REST, bulk and WebSocket

Get TD Lines with one API call

This request returns TD Lines for BTCUSDT on 1-hour Binance candles. Add your API key to run it here.

curl -G https://v2.taapi.io/indicator/tdlines \
  -H "Authorization: Bearer YOUR_API_KEY" \
  --data-urlencode "exchange=binance" \
  --data-urlencode "symbol=BTCUSDT" \
  --data-urlencode "timeframe=1h"

import requests

resp = requests.get(
    'https://v2.taapi.io/indicator/tdlines',
    headers={'Authorization': 'Bearer YOUR_API_KEY'},
    params={'exchange': 'binance', 'symbol': 'BTCUSDT', 'timeframe': '1h'},
)
print(resp.json())

const params = new URLSearchParams({"exchange": "binance", "symbol": "BTCUSDT", "timeframe": "1h"});
const res = await fetch(`https://v2.taapi.io/indicator/tdlines?${params}`, {
  headers: { Authorization: 'Bearer YOUR_API_KEY' },
});
console.log(await res.json());

TD Lines API response

This response came from the live API on 9 November 2026. Long lists are shortened here.

200 OK

{
  "open": 74288.01,
  "high": 74354.01,
  "low": 74058.45,
  "close": 74134.55,
  "tdHigh": 74244.28000000001,
  "tdLow": 73948.72000000002,
  "timestamp": [1794218400]
}

Field	Type	Description
`open`	number	Open
`high`	number	High
`low`	number	Low
`close`	number	Close
`tdHigh`	number	Td high
`tdLow`	number	Td low
`timestamp`	integer[]	Unix time of each candle, in seconds

TD Lines API parameters

Name	Type	Required	Default	Description
`exchange`	string	Yes	—	`binance`, `binancefutures`, `bybit`, `gateio`, `kraken` or `stocks`
`symbol`	string	Yes	—	Pair or ticker, e.g. `BTCUSDT` or `AAPL`
`timeframe`	string	Yes	—	`1m` `5m` `15m` `1h` `4h` `1d` `1w`
`results`	integer	No	1	Number of values to return, or `max`
`backtrack`	integer	No	0	Candles to skip from the most recent

What is TD Lines?

This endpoint returns Tom DeMark's projected high and low for the next period, calculated from the open, high, low and close of the reference candle. The candle's own prices are included in the response.

TD Lines formula

Output	Calculation
X, close below open	high + 2 × low + close
X, close above open	2 × high + low + close
X, close equals open	high + low + 2 × close
Projected high	X ÷ 2 − low
Projected low	X ÷ 2 − high

How to read TD Lines in your code

Signal	Meaning	Condition
Projected range	Expected high and low	`tdHigh` and `tdLow`
Upside break	Price beyond the projection	Close above `tdHigh`
Downside break	Price beyond the projection	Close below `tdLow`

Limitations: The projection is built from one candle, so a single unusual candle produces an unusual range. Nothing on this page is financial advice.

Read TD Lines from Python

Use backtrack=1 to read the result as of the last closed candle.

curl -G https://v2.taapi.io/indicator/tdlines \
  -H "Authorization: Bearer YOUR_API_KEY" \
  --data-urlencode "exchange=binance" \
  --data-urlencode "symbol=BTCUSDT" \
  --data-urlencode "timeframe=1h" \
  --data-urlencode "backtrack=1"

import requests

resp = requests.get(
    'https://v2.taapi.io/indicator/tdlines',
    headers={'Authorization': 'Bearer YOUR_API_KEY'},
    params={'exchange': 'binance', 'symbol': 'BTCUSDT', 'timeframe': '1h', 'backtrack': 1},
)
data = resp.json()
print(data['open'])

Get historical TD Lines values

Add results to return a series for backtesting or charting. The last element is the most recent candle.

curl -G https://v2.taapi.io/indicator/tdlines \
  -H "Authorization: Bearer YOUR_API_KEY" \
  --data-urlencode "exchange=binance" \
  --data-urlencode "symbol=BTCUSDT" \
  --data-urlencode "timeframe=1h" \
  --data-urlencode "results=100"

Get TD Lines for multiple symbols

Combine TD Lines with other indicators in one request. Each exchange, symbol and timeframe combination is one construct: Basic allows 1 per request, Pro 3 and Expert 10.

POST/bulk

curl -X POST https://v2.taapi.io/bulk \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "constructs": [
    {
      "id": "btc_1h",
      "exchange": "binance",
      "symbol": "BTCUSDT",
      "timeframe": "1h",
      "indicators": [
        {
          "id": "tdlines",
          "indicator": "tdlines"
        },
        {
          "id": "rsi",
          "indicator": "rsi"
        }
      ]
    }
  ]
}'

Stream TD Lines in real time

Subscribe over WebSocket to receive new values every 5 seconds while the candle is forming. Streaming supports 1m, 5m, 15m and 1h, and uses interval where REST uses timeframe.

WSSwss://v2.taapi.io/streaming

{
  "type": "subscribe",
  "id": "tdlines",
  "exchange": "binance",
  "symbol": "BTCUSDT",
  "interval": "1m",
  "indicator": "tdlines"
}

TD Lines API FAQ

What does the TD Lines API return?

It returns open, high, low, close, tdHigh, tdLow, plus a timestamp for the request. Results are JSON.

Is the latest TD Lines value final?

No. The newest value belongs to the candle still forming and can change until it closes. Add backtrack=1 to read the last closed candle.

Can I get TD Lines for US stocks?

Yes. Use exchange=stocks with a ticker such as AAPL. US stocks are included on the Pro plan and above.

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