# Candles · Elysium API · Femtos

> OHLCV of one pool in pair price, USD and market cap, ascending, UTC-aligned.

- Base URL: `https://api.femtos.xyz/v1` (REST) · `wss://api.femtos.xyz/v1/ws` (WebSocket) · MCP: `https://api.femtos.xyz/mcp`
- Auth: `Authorization: Bearer $FEMTOS_KEY`. Free key: https://femtos.xyz/accounts/ (browser), or with
  no browser: `GET https://femtos.xyz/accounts/agent/challenge`, solve its proof of work, then `POST https://femtos.xyz/accounts/agent/signup`
  (https://femtos.xyz/agents.md#agent-onboarding)
- Decimals are exact strings, times Unix milliseconds, addresses lowercase `0x`
- Whole API in one file: https://femtos.xyz/agents.md · OpenAPI: https://api.femtos.xyz/v1/openapi.json · Index: https://femtos.xyz/llms.txt
- Page with live calls: https://femtos.xyz/elysium/candles

## Candles — GET `/v1/candles`

OHLCV of one pool in pair price, USD and market cap, ascending, UTC-aligned.

| Param | In | Example or values |
|---|---|---|
| `layer` | query | `elysium` |
| `market` | query | `<pair>` |
| `tf` | query | `1s`, `15s`, `1m`, `5m`, `15m`, `1h`, `4h`, `1d` |
| `limit` | query | `288` |

```bash
curl -H "Authorization: Bearer $FEMTOS_KEY" "https://api.femtos.xyz/v1/candles?layer=elysium&market=<pair>&tf=5m&limit=288"
```

| Field | Type | Meaning |
|---|---|---|
| `t` | int | unit start (ms) |
| `o · h · l · c` | decimal | price in the quote token |
| `usd {o,h,l,c}` | decimal | same candle in USD |
| `mcap {o,h,l,c}` | decimal | same candle as market cap, USD |
| `v · vq` | decimal | volume in token, in quote |
| `n` | int | swaps in the unit |
| `vUsd` | decimal \| null | volume in USD |
| `mcUsd` | decimal | market cap at close; absent on filled candles |
| `from · to · fill` | query | window (ms) and flat candles for empty units (fill=1, default) |
| `asOf · height` | int | head the answer is cut at: every trade up to that block counted |

## Related (Market data)

- [Forming candle](https://femtos.xyz/elysium/ws-candles.md): The forming candle, pushed once per block where it changes.
- [Trades](https://femtos.xyz/elysium/trades.md): Latest swaps of one pool, newest first.
- [Trades stream](https://femtos.xyz/elysium/ws-trades.md): The swaps of one pool, one message per block that has some.
- [Daily token volume](https://femtos.xyz/elysium/volume.md): USD swap volume of a token per UTC day, both sides of every priced swap. Testnet pool prices.
- [Token transfers](https://femtos.xyz/elysium/transfers.md): ERC-20 Transfer events of one token, newest first.
- [Liquidity events](https://femtos.xyz/elysium/liquidity.md): Liquidity added to and removed from one pool, newest first.

All Elysium endpoints: https://femtos.xyz/elysium.md