Charting ⚠️ CRITICAL: DO NOT CALL DATA TOOLS NEVER call price_chart , get_coin_ohlc_range_by_id , twelvedata_time_series , or ANY market data tools when creating charts. Chart scripts fetch data internally. Calling these tools floods your context with 78KB+ of unnecessary data. Workflow (4 steps): Read template from skills/charting/scripts/ Write script to scripts/ Run script with bash Call read_file on the output PNG, then display it using markdown image syntax: You generate TradingView-quality candlestick charts. Dark theme, clean layout, professional colors. Every chart is a standalone Python script — no internal imports. Additional Rules: Chart scripts run in workspace and cannot import from core . Use requests library directly, NOT proxied_get() . Templates include proxy auto-configuration. If PROXY_HOST env var exists, scripts automatically configure HTTP_PROXY / HTTPS_PROXY . Tools: write_file , bash , read_file When to Use Which Chart Simple price action → Candlestick with no indicators. Good for "show me BTC this month." Trend analysis → Add EMA/SMA overlays. Good for "is ETH in an uptrend?" Momentum check → Add RSI or MACD as subplots. Good for "is SOL overbought?" Full technical view → Candles + Bollinger Bands + RSI + MACD. Good for "give me the full picture on BTC." Volume analysis → Requires separate fetch from market_chart endpoint (OHLC endpoint has no volume). Asset comparison → Line chart comparing two assets (BTC vs Gold, ETH vs S&P500, etc.). Use comparison template for normalized or percentage-based comparisons. How to Build Charts Read and customize the template scripts in skills/charting/scripts/ : chart_template.py — Baseline candlestick chart with TradingView styling (crypto via CoinGecko) chart_with_indicators.py — RSI, MACD, Bollinger Bands, EMA/SMA examples (crypto via CoinGecko) chart_stock_template.py — Stock/forex chart using Twelve Data API chart_comparison_template.py — Compare two assets (crypto vs commodity, stock vs crypto, etc.) Copy the relevant template to scripts/ , customize the config section (coin, days, indicators), and run it. The templates handle all data fetching internally with retry logic and error handling. Note: These templates are for market data visualization (price charts, indicators). For backtest result charts (equity curves, drawdowns, performance dashboards), add matplotlib charting directly to your backtest script — the data is already there, no need to re-fetch or create a separate file. TradingView Color Palette Element Color Hex Up candles Teal

26a69a

Down candles Red

ef5350

Background Dark

131722

Grid Subtle dotted

1e222d

Text / axes Light gray

d1d4dc

MA lines Blue / Orange

2196f3

/

ff9800

RSI line Purple

b39ddb

MACD line Blue

2196f3

Signal line Orange

ff9800

Do not deviate from this palette unless the user asks. Data Source APIs CoinGecko (Crypto Only) Endpoint: https://pro-api.coingecko.com/api/v3/coins/{coin_id}/ohlc/range Auth: Header x-cg-pro-api-key: {COINGECKO_API_KEY} Use for: BTC, ETH, SOL, and all cryptocurrencies Example: url = f"https://pro-api.coingecko.com/api/v3/coins/ { COIN_ID } /ohlc/range" params = { "vs_currency" : "usd" , "from" : from_ts , "to" : now , "interval" : "daily" } headers = { "x-cg-pro-api-key" : os . getenv ( "COINGECKO_API_KEY" ) } resp = requests . get ( url , params = params , headers = headers ) raw = resp . json ( )

[[timestamp_ms, open, high, low, close], ...]

Twelve Data (Stocks, Forex, Commodities) Endpoint: https://api.twelvedata.com/time_series Auth: Query param apikey={TWELVEDATA_API_KEY} Use for: Stocks (AAPL, MSFT), Forex (EUR/USD), Commodities (XAU/USD for gold) Common Symbols: Stocks: AAPL , MSFT , GOOGL , TSLA , SPY Forex: EUR/USD , GBP/JPY , USD/CHF Commodities: XAU/USD (gold), XAG/USD (silver), CL/USD (crude oil) Intervals: 1min , 5min , 15min , 30min , 1h , 4h , 1day , 1week , 1month Example: url = "https://api.twelvedata.com/time_series" params = { "symbol" : "XAU/USD" ,

Gold spot price

"interval" : "1day" , "outputsize" : 90 ,

Number of candles

"apikey" : os . getenv ( "TWELVEDATA_API_KEY" ) } resp = requests . get ( url , params = params ) data = resp . json ( )

data["values"] = [{"datetime": "2024-01-01", "open": "2050.00", "high": "2060.00", ...}, ...]

IMPORTANT: Twelve Data returns data in reverse chronological order (newest first). Always reverse the list before creating a DataFrame: values = data [ "values" ] [ : : - 1 ]

Reverse to oldest-first

Interval Selection Strategy

The templates now auto-select optimal intervals to minimize data volume while maintaining visual quality:

Time Range

Auto-Selected Interval

Rationale

≤31 days

Hourly

High granularity for short-term analysis

32-365 days

Daily

Sufficient detail, lower data volume

>365 days

Daily

Daily is optimal for long-term trends

Override:

Set

INTERVAL = "daily"

or

INTERVAL = "hourly"

in the config to override auto-selection.

Key Gotchas

savefig

facecolor

You MUST set

facecolor='#131722'

and

edgecolor='#131722'

in

savefig

, or the saved PNG reverts to white background.

Title spacing

Prefix titles with

\n

to add spacing from the top edge.

returnfig=True

Use when you need post-plot customization (price formatting, annotations). When using it, call

fig.savefig()

manually — don't pass

savefig

to

mpf.plot()

.

No volume in OHLC

CoinGecko OHLC endpoint returns

[timestamp_ms, open, high, low, close]

only. Use

volume=False

or fetch volume separately from

coin_chart

endpoint.

Panel ratios

Set

panel_ratios

when adding indicator subplots. E.g.,

(4, 1, 2)

for candles + volume + one indicator,

(5, 1, 2, 2)

for two indicators.

Figure size

Default (14, 8) . Increase to (14, 10) or (14, 12) when adding subplots. Rules Paths are relative to workspace. Write to scripts/foo.py , not workspace/scripts/foo.py . The bash CWD is already workspace. Always save to output/ directory. Use os.makedirs("output", exist_ok=True) . Always run the script with bash("python3 scripts/.py") to verify it works. Always call read_file on the generated PNG, then use markdown image syntax to display it: Scripts must be standalone. Use requests + os.getenv() . No internal imports, no dotenv. CRITICAL: Do NOT use proxied_get() in chart scripts. Chart scripts are standalone and run in the workspace - they cannot import from core.http_client . Always use requests.get() and requests.post() directly. This is an exception to the PLATFORM.md proxy rules because these scripts execute outside the main Star Child process. The templates demonstrate the correct pattern. Env vars are inherited. os.getenv("COINGECKO_API_KEY") works directly. Default to dark theme unless user asks for light. Filename should describe the chart. e.g. btc_30d_candles.png , eth_7d_rsi_macd.png . Data sources: Use CoinGecko API for crypto (BTC, ETH, etc). Use Twelve Data API for stocks, forex, and commodities (AAPL, EUR/USD, XAU/USD for gold). Never mix APIs - keep scripts focused on one data source. Think about what you're measuring: Before creating a chart, ask yourself: "What question is the user trying to answer?" A normalized chart (all start at 100) shows relative trends but hides actual gain magnitude. If the user wants to know "which gained more" or is comparing investment performance, they need the actual multipliers (e.g., 50x vs 10x), not just lines that look similar. Troubleshooting 401 Unauthorized Errors Templates auto-configure proxy from PROXY_HOST / PROXY_PORT env vars. If 401 errors occur: Check environment: bash ( "env | grep -E 'PROXY|REQUESTS_CA'" ) Expected vars: PROXY_HOST / PROXY_PORT - Proxy address (templates use these to set HTTP_PROXY/HTTPS_PROXY) REQUESTS_CA_BUNDLE - Proxy CA cert for SSL COINGECKO_API_KEY / TWELVEDATA_API_KEY - Can be fake in proxied environments If vars are missing, this is an environment configuration issue, not a script issue.