Alpaca API recent SIP data error: choose delayed SIP or explicit IEX

Symptoms

A stock-data request returns JSON code 42210000 with subscription does not permit querying recent SIP data. This is an application error code, not an HTTP status number. The official FAQ shows this body for a latest SIP trade request without the required subscription. Record the actual HTTP status, endpoint, feed and interval separately; do not assume every 403 or 422 has this cause.

Cause

Basic real-time equities cover IEX, a single exchange; SIP combines exchange reporting. The plan overview distinguishes Basic from Algo Trader Plus. For historical SIP without that subscription, the FAQ requires end to be at least 15 minutes old. Latest and snapshot SIP requests have a subscription requirement; adding a historical cutoff to those endpoints is not a workaround.

Defaults are not a reliable application contract: the FAQ describes a subscription-dependent best feed, the bars reference lists a SIP default and plan-aware end, while SDK request documentation describes end as now. The pinned alpaca-py request source allows an omitted feed. Set both fields explicitly rather than inferring wire behavior from one default description.

Safe resolution

Choose the dataset before issuing a request:

1. For delayed consolidated history on Basic, use /v2/stocks/bars, explicit feed=sip, and an eligible end. Keep start no later than end.
2. If the product accepts a single-exchange view, deliberately choose feed=iex and label returned data as IEX-only. Do not compare its volume with a consolidated total as if coverage were identical.
3. If recent consolidated data is required, verify the account entitlement. Stop with an actionable subscription message rather than retrying the same denied request or silently substituting IEX.

This standard-library helper only plans Basic stock-bars requests. It rejects a recent SIP window instead of changing the requested feed or silently shortening the interval.

from datetime import datetime, timedelta, timezone


def stock_bar_request(*, symbols, start, end, feed, now):
    # Pure request planning: no credentials and no network calls.
    if feed not in {"sip", "iex"}:
        raise ValueError("Choose sip or iex explicitly")
    if not symbols or any(not isinstance(s, str) or not s.strip() for s in symbols):
        raise ValueError("Provide stock symbols")
    for value in (start, end, now):
        if value.tzinfo is None or value.utcoffset() is None:
            raise ValueError("Use timezone-aware datetimes")
    start, end, now = (v.astimezone(timezone.utc) for v in (start, end, now))
    if start > end or end > now:
        raise ValueError("Invalid or future interval")
    if feed == "sip" and end > now - timedelta(minutes=15):
        raise ValueError("Basic SIP end must be at least 15 minutes old")
    stamp = lambda value: value.isoformat().replace("+00:00", "Z")
    return {
        "url": "https://data.alpaca.markets/v2/stocks/bars",
        "params": {"symbols": ",".join(symbols), "timeframe": "1Min",
                   "start": stamp(start), "end": stamp(end),
                   "feed": feed, "adjustment": "raw", "limit": 1000},
        "coverage": "consolidated SIP" if feed == "sip" else "IEX only",
    }


now = datetime.now(timezone.utc)
end = now - timedelta(minutes=16)
request = stock_bar_request(symbols=["AAPL"], start=end - timedelta(hours=1),
                            end=end, feed="sip", now=now)

Pass the resulting URL and params to an authenticated server-side HTTP client with the documented key/secret headers and a finite timeout. Check its HTTP status and JSON error body before treating it as data. On 42210000, stop this request path and surface the entitlement choice; generic retry/backoff cannot grant permission. Continue historical pagination using next_page_token as the next request’s page_token, retaining all original query fields. The snippet is not a complete downloader.

For current Python SDK integrations, use alpaca-py request objects such as StockBarsRequest with feed=DataFeed.SIP or DataFeed.IEX and explicit aware timestamps. Pin and test the version used by your application. Keep feed, interval, timeframe, adjustment and observation time in cache provenance; never cache an IEX result under a SIP key.

Verification

Source review on 2026-10-16 confirms the documented entitlement boundary and request fields; no authenticated Alpaca API request or live SDK test was performed.

The companion repository test runs the published pure-Python helper with synthetic clock values only. Check a SIP request ending 16 minutes ago and the exact 15-minute boundary as positive controls. A request ending 14 minutes 59 seconds ago must fail; the same recent interval with explicitly chosen IEX must remain IEX-only. Also reject a missing/unknown feed, naive time, future end and reversed interval. These fixtures do not prove account entitlement or clock synchronization.

For a later authorized live check, compare the same symbol/window with explicit feeds and capture status, application code, returned timestamps and every continuation page without secrets. A Basic latest-SIP request is the documented negative control; eligible historical SIP and explicit IEX are entitlement-dependent positive controls. Do not interpret empty bars during a quiet interval as proof of failure. No live controls were run here.

Limitations

The legacy issue #394 was opened in March 2021 and is closed; its repository was archived in June 2026. It provides historical context for end-time confusion, not evidence of a current alpaca-py bug. No installed SDK version is claimed. The helper covers Basic US equities historical bars, not paid-SIP authorization, Broker API, options, crypto, WebSocket authentication or order execution. Its one-minute safety margin is an editorial implementation choice; synchronize clocks and recheck current entitlement rules. Source and offline fixture review do not establish real API success, production deployment, Search Console indexing or search demand. See the Alpaca provider profile for scoped pricing and limits.