Resources
Limits and versioning
Rate limits, the ticker cap, freshness, caching and the v1 contract.
The API serves a stored nightly artifact, so the limits are generous for reading and the data does not change between sessions. Plan around one fetch per ticker per day.
Rate limits
| Caller | Limit | On the limit |
|---|---|---|
| A key | 60 requests a minute and 10,000 a day | 429 rate_limited with details.retry_after_seconds |
| No key (families, universe, demo, keyless MCP tools) | 30 requests a minute per IP | 429 rate_limited |
REST calls and MCP tool calls share the key's counters. Two keys on one account have separate counters.
Tracked tickers
An account tracks up to 50 tickers during the beta; the cap is on every tickers response. Pattern, history and chart calls work only on tracked tickers.
Freshness and caching
Detection runs after each US session. as_of_session on every response is the date the answer describes; an answer fetched at 9 a.m. and one fetched at 3 p.m. on the same day are the same answer. Cache by as_of_session, and refetch when the date changes rather than on a timer.
setup_id is stable while a pattern stands. If the nightly build redraws a pattern, the id changes and lineage_id ties the two together, so store both if you keep setups across days.
Versioning
The base path carries the version: https://api.tradingpal.io/api/v1 is v1, and every response says api_version: "v1". Within v1, field names do not change and fields are only added. When a v2 ships, v1 stays available for at least twelve months afterwards. Breaking changes and additions are listed in the changelog.
Plans
During the beta, keys work on Premium accounts and the limits above apply to every key. Plans built on tickers tracked follow once the beta has measured how people use the API; the tracked-ticker count is the number that will matter, not calls.
Images and redistribution
chart.png is rendered from the same data as the JSON. Use images and data inside your own tools and reports. Republishing the nightly book as a whole, or offering it to third parties as a feed, is not covered by a key.