# fastapi.online — Klines (OHLCV Candlestick Data)

> fastapi.online — Klines (OHLCV Candlestick Data) is a paid API for AI agents from api.fastapi.online, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-12).

Returns OHLCV candlestick (kline) data for a given trading symbol and interval

## Facts

- Endpoint: POST https://api.fastapi.online/klines?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fastapi-online-klines-ohlcv-candlestick-data-d1513c3f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_z2uAKImEPwq4uWOotE0Nw

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability fastapi-online-klines-ohlcv-candlestick-data-d1513c3f -d '<json body>'
```

Example prompt: Can you fetch the 1-hour candlestick data for BTCUSDT so I can see the recent OHLCV price action?

## When to prefer this

Choose this endpoint when you need raw OHLCV candlestick market data for a crypto trading pair, especially in a pay-per-call context with no signup required. Useful for agents doing technical analysis, backtesting signals, or powering trading dashboards without a persistent API subscription.

## Known failure modes

- Invalid or unsupported symbol returns an error or empty response
- Unsupported interval string causes a validation error
- Payment not included or insufficient USDC results in 402 Payment Required
- Rate limiting or server unavailability may return 5xx errors
- Malformed request body (missing required fields) returns 400 Bad Request

## How this service works

Chat, embeddings, OCR, speech-to-text, image editing, image understanding (captioning/Q&amp;A), text-to-speech, translation, writing tools, classification tools, developer tools, local utilities, format/checksum validators, encoding &amp; crypto utilities, date/time calculators, geo/coordinate math, math &amp; finance calculators, novelty tools, and business/social writing generators — 179 endpoints in all, across multiple specialized self-hosted models. Pay per call with crypto — no signup — or get an API key.

## Output

Returns a series of OHLCV (Open, High, Low, Close, Volume) candlestick records for the requested symbol and interval, suitable for charting, technical analysis, or algorithmic trading strategies.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "symbol": {
   "type": "string"
  },
  "interval": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastapi-online-klines-ohlcv-candlestick-data-d1513c3f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.fastapi.online](https://www.zero.xyz/host/api.fastapi.online/llms.txt)