Platforms
Pine Script
Also called: Pine, invite-only script, TradingView indicator
Pine Script is TradingView's own programming language for writing custom indicators and strategies that run on TradingView charts.
Pine Script is the language TradingView provides for custom indicators and strategies. Scripts are written in the Pine Editor and run on TradingView's servers, not on your computer. That is why the same indicator works in a browser on Windows or Mac, in the desktop app and in the mobile app, with nothing to install.
A Pine script runs once on every historical bar, from the oldest to the newest, and then on each update of the live bar. An indicator script plots lines, labels, shapes and tables such as a corner panel. A strategy script also simulates orders, which the Strategy Tester turns into a back-test report. The language is versioned, and the version is declared at the top of the script.
Published scripts come in three kinds. Open-source scripts show their code to everyone. Protected scripts can be added by anyone but the code is hidden. Invite-only scripts have hidden code and work only for TradingView usernames the author has granted access to. Paid indicators are normally invite-only, and access can be given or removed without touching your computer.
For Indian traders the appeal is simple: TradingView supplies the chart and the price data, so there is no separate software to set up. The limits are TradingView's own: how many indicators per chart, how many alerts, and whether a symbol's data is real-time all depend on your TradingView plan and the exchange.
The common mistake is trusting a script that repaints. Code that pulls higher-timeframe data carelessly, or acts on the live bar before it closes, can show signals in history that did not exist at the time. Watch a script live, note what it shows, and compare with the chart after a reload.
Worked example
How invite-only access works
Illustrative case. Your TradingView username is trader_sk. The author adds it to the script's access list. The script then appears in the Indicators window under Invite-only scripts, on every device where you are logged in. You add it to a 15-minute Bank Nifty chart near 56,000 and it plots like any indicator. You cannot open the source code. Under a different username the script is not there.
In WizeBuySell
All eight WizeBuySell strategies are invite-only Pine indicators. We add your TradingView username to the access list, and the script appears under Invite-only scripts in about 5 minutes, on any Windows or Mac computer and in the mobile app. Nothing is installed. It shows what to buy or sell, the strike and expiry for options, and the targets and stop-loss. TradingView's own alert features and plan limits apply.