> ## Documentation Index > Fetch the complete documentation index at: https://platform.trendlinelabs.ai/llms.txt > Use this file to discover all available pages before exploring further. # Get a market's price history bars > Price history bars (open, high, low, close) for a window you choose, at 1m to 1d. **The window** - `start` and `end` are unix milliseconds, inclusive, and must span fewer than 1000 bars at the chosen `resolution`. **The bars** - Prices are 0..1. `volume_usd` is null where the venue has no trade tape. `basis` names the price each venue's bars are built from. - Bars before 2026-10-05 23:42:28Z may pair one side's new quote with the other's old one. **Freshness** - `as_of_ms` and `cached`: when this answer was built, and whether it came from the cache. - `last_bar_ts_ms` is information, not a freshness signal: a quiet market adds no bars. **Errors** | Status | Code | When | |---|---|---| | 422 | `invalid_request` | Missing, non-integer, seconds or after-9999-12-30 bounds; start >= end; a span of 1000 bars or more; an unknown resolution. | | 422 | `venue_unsupported` | A venue whose price history is not served yet. Every venue has price history today. | | 404 | `not_found` | Unknown market. | | 404 | `venue_not_listed` | The market has no leg on that venue. | | 503 | `upstream_unavailable` | History unavailable for a venue, the market or history lookup failing or timed out, or busy (with `Retry-After`). | | 503 | `upstream_unavailable` | A bar failed our checks: a bar beyond the window's neighbouring grid points or not a finite number, a price outside 0..1, a malformed series or bar, a bar with no readable time, a bar with no price, a negative volume. | Any route can also answer 401, 403, 429, 500 or 503 `dependency_unavailable`, described on the Errors page. A failing venue is never dropped from a partial 200: the whole request is refused. ## OpenAPI ````yaml /openapi.json get /public/v1/markets/{universal_id}/candles openapi: 3.1.0 info: description: >- Read-only prediction-market data across Polymarket, Kalshi, Limitless and predict.fun over REST. Every request sends your key as `Authorization: Bearer tl_live_…`; try any endpoint from its page. title: TrendlineLabs Public API version: '1' servers: - description: Production url: https://systems.trendlinelabs.ai security: [] tags: - description: 'Read back the key you are calling with: its scopes, tier and rate limit.' name: Your key - description: Events group markets across venues; each carries a `universal_id`. name: Events - description: One market's order book, price history and trades on one venue. name: Markets - description: Current prices for a set of markets in one call. name: Prices - description: Live cross-venue price gaps on the same market. name: Opportunities paths: /public/v1/markets/{universal_id}/candles: get: tags: - Markets summary: Get a market's price history bars description: >- Price history bars (open, high, low, close) for a window you choose, at 1m to 1d. **The window** - `start` and `end` are unix milliseconds, inclusive, and must span fewer than 1000 bars at the chosen `resolution`. **The bars** - Prices are 0..1. `volume_usd` is null where the venue has no trade tape. `basis` names the price each venue's bars are built from. - Bars before 2026-10-05 23:42:28Z may pair one side's new quote with the other's old one. **Freshness** - `as_of_ms` and `cached`: when this answer was built, and whether it came from the cache. - `last_bar_ts_ms` is information, not a freshness signal: a quiet market adds no bars. **Errors** | Status | Code | When | |---|---|---| | 422 | `invalid_request` | Missing, non-integer, seconds or after-9999-12-30 bounds; start >= end; a span of 1000 bars or more; an unknown resolution. | | 422 | `venue_unsupported` | A venue whose price history is not served yet. Every venue has price history today. | | 404 | `not_found` | Unknown market. | | 404 | `venue_not_listed` | The market has no leg on that venue. | | 503 | `upstream_unavailable` | History unavailable for a venue, the market or history lookup failing or timed out, or busy (with `Retry-After`). | | 503 | `upstream_unavailable` | A bar failed our checks: a bar beyond the window's neighbouring grid points or not a finite number, a price outside 0..1, a malformed series or bar, a bar with no readable time, a bar with no price, a negative volume. | Any route can also answer 401, 403, 429, 500 or 503 `dependency_unavailable`, described on the Errors page. A failing venue is never dropped from a partial 200: the whole request is refused. operationId: getCandles parameters: - description: >- no control, format, private-use, unassigned, line or paragraph separator character in: path name: universal_id required: true schema: description: >- no control, format, private-use, unassigned, line or paragraph separator character maxLength: 256 minLength: 1 title: Universal Id type: string - description: the bar width in: query name: resolution required: true schema: description: the bar width enum: - 1m - 5m - 15m - 1h - 6h - 1d title: Resolution type: string - description: window start, unix milliseconds, inclusive in: query name: start required: true schema: description: window start, unix milliseconds, inclusive title: Start type: integer - description: window end, unix milliseconds, inclusive in: query name: end required: true schema: description: window end, unix milliseconds, inclusive title: End type: integer - description: one venue's series only; omit for every venue that lists the market in: query name: venue required: false schema: anyOf: - enum: - kalshi - polymarket - limitless - predictfun type: string - type: 'null' description: >- one venue's series only; omit for every venue that lists the market title: Venue responses: '200': content: application/json: example: as_of_ms: 1791270100000 cached: false end_ms: 1791270000000 resolution: 1h series: kalshi: bars: - close: 0.42 high: 0.43 low: 0.4 open: 0.41 ts_ms: 1791266400000 volume_usd: 1250 - close: 0.41 high: 0.42 low: 0.41 open: 0.42 ts_ms: 1791270000000 volume_usd: 310 basis: yes_ask exists: true last_bar_ts_ms: 1791270000000 venue_market_id: KXBTC-26DEC31-B100000 start_ms: 1791266400000 universal_id: mk-btc-100k-2026 schema: $ref: '#/components/schemas/PublicCandles' description: Successful Response headers: Cache-Control: description: no-store on every answer schema: type: string X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '401': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: 'unauthorized: no key, or a key that is unknown, revoked or expired.' headers: Cache-Control: description: no-store on every answer schema: type: string WWW-Authenticate: description: Bearer realm="public-api" schema: type: string X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '403': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: >- insufficient_scope: the key lacks the scope this route needs; ip_not_allowed: the request came from an address outside the key's allowlist; tier_required: the key owner's plan does not include API access; access_not_granted: API access is free but granted on request; request it on https://trendlinelabs.ai/developer. headers: Cache-Control: description: no-store on every answer schema: type: string X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '404': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: >- not_found: no such event, market or key; venue_not_listed: the market has no leg on that venue. headers: Cache-Control: description: no-store on every answer schema: type: string X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '422': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: >- invalid_request: a parameter is missing, unknown, malformed or out of bounds, or a cursor does not match; venue_unsupported: the route does not serve that venue. headers: Cache-Control: description: no-store on every answer schema: type: string X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '429': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: >- rate_limited: too many requests, or too many failed authentications; wait Retry-After seconds. headers: Cache-Control: description: no-store on every answer schema: type: string Retry-After: description: seconds to wait before retrying schema: type: integer X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '500': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: >- internal_error: an unexpected failure on our side; quote the request id. The body may instead be text/plain with no envelope and no X-RateLimit-* headers when a failure escapes the route's own handling. headers: Cache-Control: description: no-store on every answer schema: type: string X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '503': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: >- dependency_unavailable: one of our own stores could not be read; retry later; upstream_unavailable: the data source is unreadable, absent or older than its bound; never an empty 200. headers: Cache-Control: description: no-store on every answer schema: type: string Retry-After: description: seconds to wait before retrying schema: type: integer X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string security: - HTTPBearer: [] x-codeSamples: - label: cURL lang: bash source: > #!/bin/sh # getCandles: Get a market's price history bars. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base. curl -sS "${TRENDLINE_API_BASE:-https://systems.trendlinelabs.ai}/public/v1/markets/mk-btc-100k-2026/candles?resolution=1h&start=1791266400000&end=1791270000000&venue=kalshi" \ -H "Authorization: Bearer $TRENDLINE_API_KEY" - label: Python lang: python source: > """getCandles: Get a market's price history bars. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base.""" import os import requests BASE = os.environ.get("TRENDLINE_API_BASE", "https://systems.trendlinelabs.ai") KEY = os.environ["TRENDLINE_API_KEY"] r = requests.get(f"{BASE}/public/v1/markets/mk-btc-100k-2026/candles", params={"resolution": "1h", "start": "1791266400000", "end": "1791270000000", "venue": "kalshi"}, headers={"Authorization": f"Bearer {KEY}"}, timeout=10) r.raise_for_status() print(r.json()) - label: JavaScript lang: javascript source: > // getCandles: Get a market's price history bars. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base. const BASE = process.env.TRENDLINE_API_BASE ?? "https://systems.trendlinelabs.ai"; const KEY = process.env.TRENDLINE_API_KEY; const r = await fetch(`${BASE}/public/v1/markets/mk-btc-100k-2026/candles?resolution=1h&start=1791266400000&end=1791270000000&venue=kalshi`, { headers: { Authorization: `Bearer ${KEY}` } }); console.log(r.status, await r.json()); components: schemas: PublicCandles: properties: as_of_ms: description: when the history was read, unix milliseconds title: As Of Ms type: integer cached: description: true when served from a recent identical read title: Cached type: boolean end_ms: description: the window end, unix milliseconds title: End Ms type: integer resolution: description: the bar width enum: - 1m - 5m - 15m - 1h - 6h - 1d title: Resolution type: string series: additionalProperties: $ref: '#/components/schemas/PublicCandleSeries' description: one series per venue that lists the market propertyNames: enum: - kalshi - polymarket - limitless - predictfun title: Series type: object start_ms: description: the window start, unix milliseconds title: Start Ms type: integer universal_id: description: the market universal id title: Universal Id type: string required: - universal_id - resolution - start_ms - end_ms - as_of_ms - cached - series title: PublicCandles type: object PublicError: properties: error: $ref: '#/components/schemas/PublicErrorBody' description: the refusal required: - error title: PublicError type: object PublicCandleSeries: properties: bars: default: [] description: the bars in the window, oldest first items: $ref: '#/components/schemas/PublicCandle' title: Bars type: array basis: description: 'which price the bars track: the YES ask, the YES bid, or their mid' enum: - yes_ask - yes_bid - mid title: Basis type: string exists: description: false when the venue has no history for this market title: Exists type: boolean last_bar_ts_ms: anyOf: - type: integer - type: 'null' description: information only, not a liveness signal title: Last Bar Ts Ms venue_market_id: description: the market's id on this venue title: Venue Market Id type: string required: - venue_market_id - exists - basis title: PublicCandleSeries type: object PublicErrorBody: properties: code: description: >- a machine-readable code from x-known-codes; a new code may be added, so handle an unknown one by its status title: Code type: string x-known-codes: - access_not_granted - dependency_unavailable - insufficient_scope - internal_error - invalid_request - ip_not_allowed - market_closed - not_found - rate_limited - tier_required - unauthorized - upstream_unavailable - venue_not_listed - venue_unsupported message: description: a human-readable explanation; never parse it title: Message type: string request_id: description: >- this request's id, also sent as the X-Request-Id header; quote it when asking for help title: Request Id type: string required: - code - message - request_id title: PublicErrorBody type: object PublicCandle: properties: close: description: the last price in the bar, 0..1 title: Close type: number high: description: the highest price in the bar, 0..1 title: High type: number low: description: the lowest price in the bar, 0..1 title: Low type: number open: description: the first price in the bar, 0..1 title: Open type: number ts_ms: description: the bar's start, unix milliseconds title: Ts Ms type: integer volume_usd: anyOf: - type: number - type: 'null' description: >- traded volume in USD in the bar; null where the venue has no trade tape title: Volume Usd required: - ts_ms - open - high - low - close title: PublicCandle type: object securitySchemes: HTTPBearer: description: 'Authorization: Bearer tl_live_…' scheme: bearer type: http ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.