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 scan and 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 200 tickers, the same list as its watchlist on the site; the cap is on every tickers response. Pattern, history and chart calls work on any ticker, tracked or not, and history returns the last five occurrences per ticker. The scan needs no tracked ticker.
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
API and MCP access requires Premium+ subscription at $30/month; it includes all of the benefits in Premium plus API and MCP access. The limits above apply to every key on the account; two keys have separate counters. Premium alone does not unlock them.
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.