API reference · Reference markets

Get reference bars

GET/v1/reference/bars

One reference market's bars on the same clock as the venues' markets, oldest first, paged by time, with any gaps in the recording.

On this page

Auth. An API token: Authorization: Bearer lb_… (create one). Signed-in web sessions work too.

Limits. One history query per call (500 a day on Free; unlimited on Builder and Standard).

Parameters

Query parameters

Name	Type	Required	Description
`symbol`	string	yes	`BTC-USD`, `ETH-USD`, `UST-10Y`, … or `source:symbol`.
`source`	string	no	The source to read when several record the symbol.
`period`	string	no	Seconds, or `1s`, `1m` or `1d`; default the finest stored.
`since`	integer	no	ms epoch; bars whose period ends at or after it.
`until`	integer	no	ms epoch; bars whose period ends at or before it.
`limit`	integer	no	Bars per page. 1 to 5000. Default `1000`.

Request

Terminal

curl "https://api.langbot.ai/v1/reference/bars?symbol=UST-10Y&since=1793682000000&limit=2" \
  -H "Authorization: Bearer $LANGBOT_API_TOKEN"

Python

from langbot import LangbotClient

async with LangbotClient() as lb:  # reads LANGBOT_API_TOKEN
    page = await lb.reference_bars("UST-10Y", since=1793682000000, limit=2)
    for b in page.bars:
        print(b.as_of, b.close)

TypeScript

import { LangbotClient } from "@langbotai/sdk";

const lb = new LangbotClient(); // reads LANGBOT_API_TOKEN
const page = await lb.referenceBars("UST-10Y", { since: 1793682000000, limit: 2 });

Response

200 OK

JSON

{
  "symbol": "UST-10Y",
  "source": "treasury",
  "source_name": "U.S. Treasury daily par yield curve",
  "rights": "public_domain",
  "period_s": 86400,
  "periods_available": [86400],
  "since": 1793682000000,
  "until": null,
  "count": 2,
  "bars": [
    { "ts": 1793768400000, "open": null, "high": null, "low": null, "close": 4.95, "volume": null, "trades": null, "bid_close": null, "ask_close": null, "as_of": "2026-11-03" },
    { "ts": 1793854800000, "open": null, "high": null, "low": null, "close": 4.90, "volume": null, "trades": null, "bid_close": null, "ask_close": null, "as_of": "2026-11-04" }
  ],
  "gaps": [],
  "next_since": 1793854800001
}

ts is the end of each bar, so the close is known at ts. Crypto bars: USD prices, volume in coins, trades fills, bid_close/ask_close the last top of book; prices are null for a period with quotes and no trade. Daily series: as_of is the date the value is for and ts when it was known; yields and rates are percent. gaps lists holes in the recording that overlap the page (disconnect, sequence with missed_trades, stale). Pass next_since back as since for the next page.

Errors

Status	`code`	When
404	`not_found`	No reference series with that symbol, or none at `period`.
401	`auth_required`	No token was sent.
401	`token_invalid`	The token was not recognised (mistyped, revoked or expired).
422	`validation_error`	A parameter failed validation; `detail[].loc` names it.
429	`quota_exceeded`	Today's history queries are spent; `quota.resets_at` says when they reset.
429	`rate_limited`	Over your request budget; wait `Retry-After` seconds.

Every error body is {"detail": …, "code": "…"}; branch on code. All codes: Errors.