Czar28
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Live — all systems operational

Historical options data,
straight into your AI.

Every US equity option, every trading day. Plug a single API key into Claude Code, Codex, Cursor, or any agent — and let it pull EOD quotes, intraday ticks, trade prints, and full chain snapshots on demand.

Start free — 1,000 requestsRead the docsSee pricing

No credit card required · Cancel anytime · 99.9% uptime

Works with

Claude CodeDrop your key in — Claude queries options data directly.
CodexAdd the API as a tool — Codex pulls quotes and chains on demand.
CursorWire it into an MCP or fetch tool — Cursor calls it inline.

Endpoints

EOD Quote Snapshot
curl https://api.czar28.com/v1/options/quote/eod \
  -H "Authorization: Bearer sopk_live_..." \
  -G --data-urlencode "root=AAPL" \
     --data-urlencode "exp=20260116" \
     --data-urlencode "strike=180" \
     --data-urlencode "right=C" \
     --data-urlencode "start_date=20250101" \
     --data-urlencode "end_date=20250601"

System Status

All systems operational
99.9% Uptime SLA →

Data quality

Institutional-grade

Low-latency historical options feed, sourced directly from US exchanges.

Coverage

12y+
History
5.2k
Tickers
1B+
Quotes served

Pricing

$0 / month to start

1,000 free requests every month. Upgrade when you need more.

Quickstart

Wire it into your agent in 30 seconds.

Pick your tool. Paste the prompt. Your agent now has a Bloomberg-grade options dataset on tap.

1. Expose your key once

In your shell: export CZAR28_API_KEY=sopk_live_… — Claude Code will pick it up via the Bash tool.

Drop-in prompt
You have access to the Czar28 historical options API at https://api.czar28.com/v1.
Auth: header "Authorization: Bearer $CZAR28_API_KEY".
Endpoints: /options/chain, /options/quote/eod, /options/quote/intraday, /options/trades.
When I ask about options pricing, IV, or chains, call the API with curl (or fetch in Node) and reason on the JSON. Use --data-urlencode for query params.

Task: Pull AAPL Jan 16 2026 180-strike call EOD quotes from Jan 1 to Jun 1, 2025, and tell me the realized IV range.
Tool call Claude will run
curl https://api.czar28.com/v1/options/quote/eod \
  -H "Authorization: Bearer $CZAR28_API_KEY" \
  -G --data-urlencode "root=AAPL" \
     --data-urlencode "exp=20260116" \
     --data-urlencode "strike=180" \
     --data-urlencode "right=C" \
     --data-urlencode "start_date=20250101" \
     --data-urlencode "end_date=20250601"

Replace sopk_live_… with your key from the dashboard. Full reference in the docs.

Get a key in 60 seconds.

  • Free tier forever
  • Bearer-token auth
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