★ Flagship AI capability
Describe Any Indicator, Your AI Builds It
Tell your AI agent what you want to see, it invents the indicator, and renders it live on your MyLinedChart chart. Your whole chart toolkit, driven by conversation.
What is a custom formula indicator?
- MyLinedChart ships a full library of built-in indicators, MA, EMA, SMA, BOLL, MACD, RSI, VWAP, and many more
- A custom formula indicator goes beyond that library: one your AI agent invents on the spot from what you describe in plain language
Simply ask for…
“the gap between a 20 and 50 SMA”
“RSI smoothed by a 5-bar average”
“price minus its 21-period EMA”
“20-bar volatility of the close”
“the highest high of the last 20 bars”
“the 10-day average volume”
Your AI translates that into an indicator that renders on your chart exactly like a built-in indicator.
How the sandbox keeps it safe
A custom formula can reference your chart's own price data and indicators.
An unsupported or malformed indicator is rejected before it's ever written to your chart, with a specific error shown to you. The worst case if something is off is a wrong or mislabeled line on your chart.
How to use it
- Download the MyLinedChart desktop app and enable the direct connection.
- Point a connected AI agent, Claude Code, Codex, or any MCP client, at it.
- Describe the indicator you want in plain language and ask your agent to add it.
- Confirm the proposed change when prompted, it renders on your chart immediately after.
Further reading
See every built-in indicator, or the full MCP toolkit, including propose_chart_changes and its drawing and indicator capabilities. Explore every chart drawing tool and note type your AI can add, review the MyLinedChart product overview, or compare plans and pricing.
Custom Formula Indicators FAQ
What can a custom formula indicator actually do?
It computes a restricted math expression over your chart's own price data, open, high, low, close, volume, plus hl2, hlc3, and ohlc4, using window functions like sma, ema, wma, rsi, stdev, highest, lowest, and sum, a ref() look-back for earlier bars, and basic arithmetic. It renders as a line on your chart, same as a built-in indicator.
Can a custom formula indicator run arbitrary code?
No. There is no code execution, no eval, no scripting language, no access to anything outside the fixed set of price-data variables and window functions. An invalid or unsupported formula is rejected before it's ever written, with a specific parse error. Worst case if something is wrong, you get a mislabeled or incorrect line, never a trade, never account access, never a security risk.
Is my custom indicator synced to the cloud?
No. Custom formula indicators are local to your device. They render on your chart and are visible to your AI agent via the direct connection, but they are never uploaded to cloud sync.
What built-in indicators does MyLinedChart have?
A full library, MA, EMA, SMA, BOLL, MACD, RSI, KDJ, CCI, DMI, VWAP, and many more. Custom formula indicators go beyond that library, invented on demand from a formula when you need something the built-ins don't cover.
Does this add a new MCP tool?
No. Custom formula indicators are a capability of the existing propose_chart_changes tool, one of MyLinedChart's nine MCP tools. No new tool was added.